MINI Cooper 1969-2001, Cooper S 1969-2001, 1000 1969-2001 User Manual

1
Chapter 1
Routine maintenance and servicing
Air cleaner element renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Air pump drivebelt check and renewal . . . . . . . . . . . . . . . . . . . . . . . 9
Brake fluid renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Carburettor idle speed and mixture adjustment . . . . . . . . . . . . . . . . 26
Contact breaker points check and adjustment . . . . . . . . . . . . . . . . . 20
Control box cleaning and inspection . . . . . . . . . . . . . . . . . . . . . . . . . 24
Coolant renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Distributor cap, rotor arm and HT lead check . . . . . . . . . . . . . . . . . . 32
Distributor lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Door, boot and bonnet check and lubrication . . . . . . . . . . . . . . . . . . 27
Driveshaft gaiter check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Drum brake adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Emission control equipment check . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Engine/transmission oil and filter renewal . . . . . . . . . . . . . . . . . . . . . 13
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Fan belt check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Front brake wear check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Fuel filter renewal (fuel injection models) . . . . . . . . . . . . . . . . . . . . . . 37
Fuel system components, checks and lubrication . . . . . . . . . . . . . . 19
Handbrake check and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Ignition timing check and adjustment . . . . . . . . . . . . . . . . . . . . . . . . 25
Intensive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Rear brake wear check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Road test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Spark plug renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Underbody and fuel/brake line check . . . . . . . . . . . . . . . . . . . . . . . . 6
Underbonnet check for fluid leaks and hose condition . . . . . . . . . . . 18
Valve clearance adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1•1
Contents
Easy, suitable for
novice with little experience
Fairly easy, suitable for beginner with some experience
Fairly difficult,
suitable for competent DIY mechanic
Difficult, suitable for experienced DIY mechanic
Very difficult,
suitable for expert DIY or professional
Degrees of difficulty
5
4
3
2
1
1•2 Servicing specifications
Lubricants and fluids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Refer to end of “Weekly Checks
Capacities
Engine oil with filter change
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 litres
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0 litres
Engine oil without filter change (approximate)
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 litres
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 litres
Cooling system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 litres
Fuel tank
Saloon and Clubman (approximate):
Early models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 litres
Later models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 litres
Estate, Van and Pick-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 litres
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 litres
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 litres
Engine
Oil filter type:
Pre-1973 models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion X101 (cartridge type)
1974-on models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion C103 (canister type)
Cooling system
Fan belt adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.0 mm deflection of belt between crankshaft and dynamo/alternator
pulleys
Specified antifreeze mixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30% antifreeze/70% water
Note: Refer to Chapter 3 for further details.
Fuel system - carburettor models
Air cleaner element type:
Pre-1973 models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion W131
1974-on models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion W125
1990-on 1275 cc models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion W250
Fuel system - fuel injection models
Air cleaner element type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion type not available
Fuel filter type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion type not available
Exhaust and emission control systems
Air pump drivebelt adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.0 mm deflection of belt between pulleys
Ignition system
Spark plugs:*
Type:
All models up to 1987 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion RN9YCC or RN9YC
998 cc engine models, 1987 to 1989 . . . . . . . . . . . . . . . . . . . . . . . Champion N12YCC or N12YC
998 cc engine models (1989-on) . . . . . . . . . . . . . . . . . . . . . . . . . . Champion RN12YCC or RN12YC
1275 cc engine models (1990-on) . . . . . . . . . . . . . . . . . . . . . . . . . Champion RN9YCC or RN9YC
Electrode gap:
All Champion plug types except RN9YC and N12YC . . . . . . . . . . 0.8 mm
Champion RN9YC and N12YC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.6 mm
HT leads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion LS-02, boxed set
*Spark plug types and electrode gaps are as recommended by Champion Spark Plug. If alternative plugs are used, refer to their manufacturer’s recommendations.
Clutch
Clutch return stop clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.50 mm
Brakes
Minimum brake shoe lining thickness . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 mm
Minimum brake pad thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 mm
Handbrake lever travel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 clicks of ratchet
Tyres
Tyre pressures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See “Weekly checks”
Torque wrench settings Nm lbf ft
Engine/transmission oil drain plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 25
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Roadwheel nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 45
Maintenance schedule 1•3
1
Every 250 miles (400 km) or weekly
mm Refer to “Weekly Checks”
Every 3000 miles (5000 km) or 3 months, whichever comes first
In addition to the items listed above, carry out the following:
mm Adjust the front and rear drum brakes (Section 3) mm Check the operation of the handbrake and adjust if
necessary (Section 4)
mm Check the condition and security of the steering
and suspension components (Section 5)
mm Inspect the underbody and the brake hydraulic
pipes and hoses (Section 6)
mm Check the condition of the fuel lines (Section 6) mm Check the condition and security of the exhaust
system (Section 7)
mm Check the condition of the fan belt and renew if
necessary (Section 8)
mm Check the condition of the air pump drivebelt
(where applicable) and renew if necessary (Section 9)
mm Inspect the clutch hydraulic components
(Section 10)
mm Check the condition of the seats and seat belts
(Section 11)
mm Check the headlight beam alignment (Section 12)
Every 6000 miles (10 000 km) or 6 months, whichever comes first
In addition to the items listed above, carry out the following:
mm Renew the engine/transmission oil and filter
(Section 13)
mm Check the condition of the front brake shoes and/or
pads, and renew if necessary (Section 14)
mm Check the condition of the driveshaft gaiters
(Section 15)
mm Lubricate the suspension and steering grease
points (Section 16)
mm Check the condition of the rear brake shoes and
renew if necessary (Section 17)
mm Check all underbonnet components and hoses for
fluid leaks (Section 18)
mm Check and if necessary top up the carburettor
piston dashpot and lubricate the linkage (Section 19)
Every 6000 miles (10 000 km) or 6 months, whichever comes first (continued)
mm Check the condition of the contact breaker points
and adjust or renew (Section 20)
mm Lubricate the distributor (Section 21) mm Check and if necessary adjust the clutch return
stop (Section 22)
mm Lubricate the dynamo bearing - early models
(Section 23)
mm Clean and inspect the dynamo charging system
control box (Section 24)
mm Check and if necessary adjust the ignition timing
(Section 25)
mm Check and if necessary adjust the carburettor idle
speed and mixture settings (Section 26)
mm Lubricate the locks and hinges (Section 27) mm Check the condition of the exterior trim and
paintwork (Section 28)
mm Road test (Section 29)
Note: Renewal of the engine/transmission oil and filter at this service interval is only necessary on pre-1985 models. On all other models, oil and filter renewal is recommended at 12 000 miles/12 months.
Every 12 000 miles (20 000 km) or 12 months, whichever comes first
In addition to the items listed above, carry out the following:
mm Renew the air cleaner element (Section 30) mm Check and if necessary adjust the valve clearances
(Section 31)
mm Inspect the distributor cap, rotor arm and HT leads
(Section 32)
mm Renew the spark plugs (Section 33) mm Check the emission control equipment (Section 34)
Every 24 000 miles (40 000 km) or twenty four months, whichever comes first
In addition to the items listed above, carry out the following:
mm Renew the coolant (Section 35) mm Renew the brake fluid (Section 36) mm Renew the fuel filter - fuel injection models
(Section 37)
The maintenance intervals in this manual are provided with the assumption that you, not the dealer, will be carrying out the work. These are the average maintenance intervals recommended by the manufacturer for vehicles driven daily under normal conditions. Obviously some variation of these intervals
may be expected depending on territory of use, and conditions encountered. If you wish to keep your vehicle in peak condition at all times, you may wish to perform some of these procedures more often. We encourage frequent maintenance because it enhances the efficiency, performance and resale value
of your vehicle.
If the vehicle is driven in dusty areas, used to tow a trailer, driven frequently at slow speeds (idling in traffic) or on short journeys, more frequent maintenance intervals are recommended.
1•4 Maintenance - component location
Underbonnet view of a 998 cc Mini 1000 Saloon
1 Brake master cylinder reservoir 2 Clutch master cylinder reservoir 3 Fuse block 4 Carburettor piston damper 5 Air cleaner
6 Windscreen wiper motor 7 Radiator pressure cap 8 Engine/transmission oil filler cap 9 Alternator 10 Engine/transmission oil dipstick
11 Distributor 12 Ignition coil 13 Vehicle identification plate 14 Clutch slave cylinder 15 Windscreen washer reservoir
Maintenance - component location 1•5
1
Underbonnet view of a 1275 cc Mini Cooper Saloon
(air cleaner removed for clarity)
1 Alternator 2 Ignition coil 3 Engine/transmission oil dipstick 4 Engine management (fuel
injection/ignition) ECU
5 Radiator pressure cap
6 Brake fluid reservoir cap 7 Brake system vacuum servo unit 8 Relay module 9 Fuel cut-off inertia switch 10 Manifold absolute pressure (MAP)
sensor fuel trap
11 Fuel return pipe 12 Fuel feed pipe 13 Accelerator cable 14 Throttle body assembly 15 Heater coolant valve 16 Charcoal canister purge valve
1•6 Maintenance - component location
Front underside view of a 998 cc Mini 1000 Saloon
1 Engine/transmission oil drain plug 2 Oil filter 3 Front suspension tie-bar 4 Disc brake caliper 5 Driveshaft outer CV joint
6 Front subframe 7 Subframe rear mounting 8 Offset sphere type inner CV joint 9 Gearchange extension rod 10 Battery positive cable
11 Steering tie-rod outer balljoint 12 Lower suspension arm 13 Exhaust bracket
Maintenance - component location 1•7
1
Rear underside view of a 998 cc Mini 1000 Saloon
1 Rear subframe 2 Rear brake wheel cylinder attachment
3 Exhaust rear silencer 4 Battery box 5 Exhaust mounting
6 Handbrake cable guide 7 Battery positive cable
1 Introduction
1 This Chapter is designed to help the home
mechanic maintain his/her vehicle for safety, economy, long life and peak performance. 2 This Chapter contains a master maintenance schedule, followed by Sections dealing specifically with each task in the schedule. Visual checks, adjustments, component renewal and other helpful items are included. Refer to the accompanying illustrations of the engine compartment and the underside of the vehicle for the locations of the various components. 3 Servicing your vehicle in accordance with the mileage/time maintenance schedule and the following Sections will provide a planned maintenance programme, which should result in a long and reliable service life. This is a comprehensive plan, so maintaining some items but not others at the specified service intervals will not produce the same results. 4 As you service your vehicle, you will discover that many of the procedures can ­and should - be grouped together, because of the particular procedure being performed, or because of the close proximity of two otherwise-unrelated components to one another. For example, if the vehicle is raised for any reason, the exhaust should be inspected at the same time as the suspension and steering components. 5 The first step of this maintenance programme is to prepare yourself before the actual work begins. Read through all the Sections relevant to the work to be carried out, then make a list and gather together all
the parts and tools required. If a problem is encountered, seek advice from a parts specialist or a dealer service department.
2 Intensive maintenance
1 If, from the time the vehicle is new, the
routine maintenance schedule is followed closely, and frequent checks are made of fluid levels and high-wear items, as suggested throughout this manual, the engine will be kept in relatively good running condition, and the need for additional work will be minimised. 2 It is possible that there will be some times when the engine is running poorly due to the lack of regular maintenance. This is even more likely if a used vehicle, which has not received regular and frequent maintenance checks, is purchased. In such cases, additional work may need to be carried out, outside of the regular maintenance intervals. 3 If engine wear is suspected, a compression test (refer to Chapter 2A) will provide valuable information regarding the overall performance of the main internal components. Such a test can be used as a basis to decide on the extent of the work to be carried out. If, for example, a compression test indicates serious internal engine wear, conventional maintenance as described in this Chapter will not greatly improve the performance of the engine, and may prove a waste of time and money, unless extensive overhaul work (Chapter 2B) is carried out first. 4 The following series of operations are those often required to improve the performance of a generally poor-running engine:
Primary operations
a) Clean, inspect and test the battery (See
“Weekly checks”).
b) Check all the engine-related fluids (See
“Weekly checks”).
c) Check and if necessary adjust the valve
clearances (Section 31).
d) Check the condition of the fan belt
(Section 8).
e) Top up the carburettor piston damper
(Section 19)
f) Check the condition and adjustment of
the contact breaker points (Section 20).
g) Inspect the distributor cap, rotor arm and
HT leads (Section 32). h) Renew the spark plugs (Section 33). i) Check and if necessary adjust the ignition
timing (Section 25). j) Check the condition of the air cleaner
filter element and renew if necessary
(Section 30). k) Check and if necessary adjust the
carburettor idle speed and mixture
settings (Section 26). l) Renew the fuel filter - fuel injection
models (Section 37). m)Check the condition of all hoses, and
check for fluid leaks (Section 18).
5 If the above operations do not prove fully effective, carry out the following operations:
Secondary operations
All the items listed under “Primary operations”, plus the following:
a) Check the charging system (Chapter 5A). b) Check the ignition system (Chapter 5B). c) Check the fuel system (Chapter 4A and B). d) Renew the distributor cap and rotor arm
(Section 32). e) Renew the ignition HT leads (Section 32).
3 Drum brake adjustment
2
1 As wear takes place on the brake shoe friction material, the clearance between the friction material and the inner circumference of the brake drum will increase, resulting in excessive brake pedal travel before the brakes are applied. To compensate for this, adjusters are provided at the rear of each brake backplate, enabling the clearance between the brake shoe and drum to be kept to a minimum. 2 At the front two adjusters are fitted to each brake backplate. At the rear a single adjuster is located at the top of each brake backplate.
Front brakes
3 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”).
4 Each front brake has two adjusters of the eccentric cam type, accessible from the rear of each brake backplate. One of these adjusters is located behind the steering arm and insufficient clearance exists to enable an ordinary brake adjusting spanner to be used. Providing the adjuster is not excessively tight or partially seized in the backplate, a 5⁄16 in AF open-ended spanner can be used quite successfully to turn the adjuster. 5 Begin by turning one of the adjusters in the forward direction of wheel rotation until the wheel is locked (see illustration). Now back it off slightly, until the wheel turns freely. The brake drum may rub slightly in one or two places as the wheel is turned. This is acceptable providing the wheel does not bind.
Caution: If, when attempting to adjust the brakes, the square-headed adjuster is reluctant to turn, it is quite likely that it has become seized in its housing. If this is the case do not force it, or you will probably break off the square head, necessitating
renewal of the complete backplate assembly. Apply liberal amounts of penetrating oil to the rear of the adjuster and allow it to soak in. Now turn the adjuster back and forth slightly, using gentle force if necessary, increasing the movement each time. When the adjuster turns easily apply a multipurpose grease to
1•8 Maintenance procedures
Every 3000 miles or 3 months
3.5 Adjusting one of the front brake
adjusters with a brake adjusting spanner
the exposed portion of the adjuster at the rear of the backplate and then turn it through its entire travel. Preferably do this with the brake drum removed.
6 Turn the second adjuster also in the direction of forward wheel rotation until the drum locks again. Now back the adjuster off until the wheel turns freely once more. 7 Repeat this procedure for the other front wheel and then lower the car to the ground.
Rear brakes
8 Chock the front wheels then jack up the rear of the car and support it on axle stands (see “Jacking and vehicle support”). Ensure that the handbrake is off. 9 Using a brake adjusting spanner, turn the square-headed adjuster in a clockwise direction (viewed from the rear of the backplate) until the wheel is locked (see illustration). The adjusters on the rear brakes are even more prone to seizure than those at the front. If the adjuster is reluctant to turn attempt to free it off as described above. If this fails, remove the rear brake drums and brake shoes as described in Chapter 9, and clean and lubricate the adjuster thoroughly. When all is well, refit the brake assemblies and start the adjustment procedure again. 10 Now turn the adjuster back a quarter of a
turn at a time until the wheel turns freely without binding. A slight rubbing may be felt when the wheel is turned slowly, indicating a high spot on the drum or dust on the linings. This is acceptable providing the drum does not bind. 11 Repeat this procedure for the other rear brake then, before lowering the car to the ground, check the handbrake adjustment as described in the following Section.
4 Handbrake check and
adjustment
2
1 Adjustment of the handbrake cables is usually only necessary after high mileage when a slight stretching of the cables will have taken place, or if the cables have been removed. 2 Before adjusting the handbrake check that the footbrake is correctly adjusted as described in Section 3. 3 Chock the front wheels then jack up the rear of the car and support it on axle stands (see “Jacking and vehicle support”). 4 Apply the handbrake lever to the third notch of the ratchet and check that the rear wheels are locked. If not, adjust the handbrake as follows. 5 With the handbrake still applied to the third click of the ratchet, tilt the front seats forward, and on models having twin cables, tighten the cable adjusting nuts at the base of the lever until the rear wheels can only just be turned by heavy hand pressure. On models having a single front cable, slacken the locknut and rotate the cable adjusting nut. When the wheels can only just be turned by heavy hand pressure, tighten the locknut (see
illustrations). 6 Release the handbrake lever and ensure
that the wheels rotate freely. If satisfactory lower the car to the ground.
5 Steering and suspension
check
2
Steering
1 First check for wear in the steering tie-rod outer balljoints. Turn the steering to left or right lock sufficiently to allow the joints to be observed. Now have an assistant turn the steering wheel back and forth slightly. If there is any side movement in the balljoint it must be renewed. Similarly place your hand over the rubber gaiter at the end of the rack housing and feel for any excess free play of the inner balljoint. If the condition of this joint is suspect, a further investigation should be carried out with the gaiter removed as described in Chapter 10. 2 Check the tightness of the steering column clamp bolt at the base of the column. Any slackness at this joint can also show up as free play at the steering wheel.
Front suspension
3 To inspect the front suspension, chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). 4 Visually inspect the balljoint dust covers and the steering gear gaiters for splits, chafing or deterioration. Any wear of these components will cause loss of lubricant, together with dirt and water entry, resulting in rapid deterioration of the balljoints or steering gear. 5 Grasp the roadwheel at the 12 o’clock and 6 o’clock positions and try to rock it. If any movement is felt it is likely to be in one or more of the following areas:
Hub bearings
6 Continue rocking the wheel while your
assistant depresses the footbrake. If the
Every 3000 miles or 3 months 1•9
1
3.9 Adjusting the rear brakes
4.5a Handbrake adjustment on models with twin cables 4.5b Handbrake cable adjusting nut on models with a single front cable
movement disappears or becomes less severe, then the wheel hub bearings in the swivel hub are at fault. Any perceptible movement at all indicates wear in the hub bearings, and they should be renewed as described in Chapter 10.
Swivel hub balljoints
7 Wear of the swivel hub balljoints is fairly
common on Minis and will be quite obvious on inspection because the whole swivel hub will appear to move in relation to the suspension arms as the wheel is rocked. If this is the case, the balljoints should be adjusted, or if badly worn, renewed; these procedures are contained in Chapter 10.
Suspension arm mountings
8 Check for wear of the lower arm inner
mounting bushes where the arm is bolted to the subframe. If the bushes are worn, the arm will appear to move in and out as the wheel is rocked. 9 The upper arm inner roller bearings cannot be inspected without partially dismantling the suspension because the rubber cone spring or displacer unit holds the arm in tension and any wear will not be evident. It can be removed for closer inspection if required as described in Chapter 10; however, wear of the upper arm and its bearings is uncommon. 10 With the brakes still firmly applied, try to rotate the wheel back and forth. If any movement is now felt, examine the tie-bar between the lower suspension arm and subframe for wear or deterioration of the rubber bushes.
Rear suspension
11 To check the rear suspension for wear, chock the front wheels then jack up the rear of the car and support it on axle stands (see “Jacking and vehicle support”). 12 Wear of the rear suspension components can often be felt when driving the car as a tendency for the rear of the vehicle to wander over uneven road surfaces or when cornering.
To isolate the worn components, grasp the roadwheel at the 12 o’clock and 6 o’clock positions and try to rock it. If any movement is felt, it is likely to be in one of the following areas:
Hub bearings
13 Continue rocking the wheel while an
assistant depresses the footbrake. If the movement disappears or becomes less pronounced, then the bearings in the rear hub are at fault. The bearings should be renewed if there is any appreciable movement whatsoever.
Radius arm bearings
14 With the footbrake still applied, continue
rocking the wheel and observe the front of the radius arm. If it can be seen to move appreciably up and down, then wear has taken place in the roller or plain bearing in the radius arm, or on the pivot shaft. If this is the case, the radius arm should be removed for overhaul as described in Chapter 10.
6 Underbody and fuel/brake
line check
1
1 With the vehicle raised and supported on axle stands (see “Jacking and vehicle support”), or over an inspection pit, thoroughly inspect the underbody and wheel arches for signs of damage and corrosion. In particular, examine the bottom of the side sills, and any concealed areas where mud can collect. Where corrosion and rust is evident, press and tap firmly on the panel with a screwdriver, and check for any serious corrosion which would necessitate repairs. If
the panel is not seriously corroded, clean away the rust, and apply a new coating of underseal. Refer to Chapter 11 for more details of body repairs. 2 At the same time, inspect the treated lower body panels for stone damage and general condition. 3 Examine the subframes carefully, particularly the side members of the rear subframe. Corrosion here is a common occurrence on Minis, particularly older models, and is one of the main causes of MOT test failure on these cars (see illustration). Where corrosion has reached an advanced stage, renewal of the subframe is the only satisfactory cure. 4 Inspect all of the fuel and brake lines on the underbody for damage, rust, corrosion and leakage. Also make sure that they are correctly supported in their clips. The battery positive cable which runs under the car from front to rear is a common problem area as it is prone to damage or chafing if not properly routed or secured. 5 Inspect the flexible brake hoses in the vicinity of the backplates or front calipers, where they are subjected to most movement (see illustration). Bend them between the fingers (but do not actually bend them double, or the casing may be damaged) and check that this does not reveal previously hidden cracks, cuts or splits.
7 Exhaust system check
1
1 With the engine cold (at least three hours after the vehicle has been driven), check the complete exhaust system, from its starting point at the engine to the end of the tailpipe. Ideally, this should be done on a hoist, where unrestricted access is available; if a hoist is not available, raise and support the vehicle on axle stands (see “Jacking and vehicle support”).
1•10 Every 3000 miles or 3 months
6.3 Advanced state of corrosion on rear subframe side member 6.5 Inspect the flexible brake hoses in the vicinity of the backplates
Wear in the rear hub bearings can often be confirmed by slowly turning the wheel with
your hand on the tyre. Worn bearings usually exhibit a roughness which can be felt as the wheel is turned.
2 Check the pipes and connections for evidence of leaks, severe corrosion, or damage. Make sure that all brackets and rubber mountings are in good condition, and tight; if any of the mountings are to be renewed, ensure that the replacements are of the correct type. Failure of the rear mounting rubber blocks on the rear subframe is a common problem - check these carefully (see illustrations). Leakage at any of the joints or in other parts of the system will usually show up as a black sooty stain in the vicinity of the leak. 3 At the same time, inspect the underside of the body for holes, corrosion, open seams, etc. which may allow exhaust gases to enter the passenger compartment. Seal all body openings with silicone or body putty. 4 Rattles and other noises can often be traced to the exhaust system, especially the rubber mountings. Try to move the system, silencer(s) and catalytic converter. If any components can touch the body or suspension parts, secure the exhaust system with new mountings.
8 Fan belt check and renewal
2
Note: If the car is fitted with exhaust emission control equipment it will first be necessary to remove the air pump drivebelt as described in Section 9 to allow access to the fan belt.
Check and adjustment
1 Release the three retaining lugs and remove the engine ignition shield, if fitted. Rotate the crankshaft so that the entire length of the fan belt can be examined. On manual transmission models, the engine can be rotated quite easily by engaging top gear and moving the car backwards or forwards to allow the belt to be inspected. This should only be done on level ground; and make sure that the car cannot run away! An alternative
method, and the method that should be used on automatic transmission models, is to press the fan belt midway between the water pump pulley and dynamo or alternator pulley and then turn the fan blades.
2 Examine the belt for cracks, splitting, fraying or damage. Check also for signs of glazing (shiny patches) and for separation of the belt plies. Renew the fan belt if worn or damaged. 3 If the condition of the belt is satisfactory, check the adjustment as follows. 4 It is most important to keep the fan belt correctly adjusted; If the belt is too loose it will slip and wear rapidly, resulting in inefficient operation of the water pump and dynamo or alternator. If it is too tight, it will impose excessive strain on the bearings of the water pump, dynamo or alternator causing premature failure of these components. 5 The fan belt tension is correct when there is 13 mm of fan belt deflection, using light finger pressure, at a point midway between
the crankshaft and dynamo or alternator pulleys. 6 To adjust the fan belt, slacken the mounting bolts of the dynamo or alternator, and also the nut on the adjusting arm located below the water pump (see illustration). Now move the unit either in or out until the correct tension is obtained. It is easier if the adjusting arm nut is only slackened a little so it requires some force to move the dynamo or alternator. In this way the tension of the belt can be arrived at more quickly than by making frequent adjustments. If difficulty is experienced in moving the dynamo or alternator away from the engine, a long spanner or bar placed behind the unit and resting against the block serves as a very good lever and can be held in position while the adjusting and mounting bolts are fully tightened. When levering on an alternator, only lever on the drive end or damage may occur. 7 When the tension is correct, tighten the adjusting arm nut first, followed by the mounting bolts.
Renewal
8 To remove the fan belt, slacken the two dynamo or alternator upper mountings and the nut on the adjusting arm below the water pump (see illustrations).
Every 3000 miles or 3 months 1•11
1
8.6 Dynamo adjusting arm nut located below the water pump
7.2a Exhaust front mounting block . . . 7.2b . . . and rear mounting block on rear subframe
8.8a Dynamo mountings and adjustment points
1 Adjustment arm retaining nuts 2 Securing nut and bolt (rear)
3 Securing nut and bolt (front)
When checking the exhaust, pay particular attention to the mounting on the transmission.
Movement of the engine causes this mounting to work loose, causing an annoying squeak or rattle when accelerating and decelerating.
Turning the engine will be easier if the spark plugs are removed first - see Section 33.
9 Push the dynamo or alternator toward the engine and lift the old belt off the three pulleys. Feed the belt over each fan blade in turn and withdraw it from behind the fan cowling at the special gap just below the top hose (see illustration). 10 Fit the new belt over the fan blades in the same way and then place it in position on the three pulleys. 11 Adjust the fan belt tension as described previously then refit the air pump drivebelt, where applicable, as described in the following Section. Note: After fitting a new fan
belt, check and if necessary readjust the tension after 250 miles (400 km).
9 Air pump drivebelt check
and renewal
2
Check and adjustment
1 The checks and adjustment procedure for the air pump drivebelt are basically the same as described in Section 9 for the fan belt. Adjust the tension of the drivebelt so that there is 13 mm deflection of the belt, using thumb pressure, at a point midway between the two pulleys.
Renewal
2 Release the three retaining lugs and remove the engine ignition shield, if fitted. 3 Undo and remove the two bolts securing the radiator upper mounting bracket to the radiator.
4 Unscrew the radiator filler cap and slacken the top hose securing clips. Carefully ease the radiator as far as possible toward the wing valance. Place a container beneath the engine to catch the small quantity of coolant that will be lost as the top hose is released.
Warning: If the engine is hot, take precautions against scalding.
5 Slacken the air pump pivot and adjusting link bolts, push the pump in toward the engine, and slip the drivebelt off the two pulleys. 6 Feed the belt between the fan blades and the radiator cowling at the top as the blades are rotated. Now pull the belt out from between the fan and radiator. 7 Refitting the drivebelt is the reverse sequence to removal, adjusting the tension as described previously. Top up the cooling system as described in “Weekly Checks” on completion.
10 Clutch hydraulic check
1
1 Check that the clutch pedal moves smoothly and easily through its full travel, and that the clutch itself functions correctly, with no trace of slip or drag. 2 Apply a few drops of light oil to the clutch pedal pivot. 3 From within the engine compartment check the condition of the fluid lines and hoses.
Check for signs of fluid leaks around the slave cylinder rubber boot or from the feed pipe and hose. Apply a few drops of oil to the clutch operating lever clevis pin and the pivot on the flywheel housing.
11 Seats and seat belt check
1
1 Check that the seats are securely attached to the floor crossmember and that there is no sign of corrosion anywhere near the mountings. Check that the seats release and then lock in place when the release mechanism is operated. 2 Check the seat belts for satisfactory operation and condition. Inspect the webbing for fraying and cuts. Check that they retract smoothly and without binding into their reels. 3 Check the seat belt mountings, ensuring that all the bolts are securely tightened.
12 Headlight beam alignment
check
5
Accurate adjustment of the headlight beam is only possible using optical beam-setting equipment, and this work should therefore be carried out by a Rover dealer or service station with the necessary facilities.
Basic adjustments can be carried out in an emergency, and further details are given in Chapter 12.
1•12 Every 3000 miles or 3 months
8.8b Alternator mounting and adjustment points
1 Adjustment arm fixings 2 Securing nut and bolt (rear)
3 Securing nut and bolt (front)
8.9 The gap in the radiator shroud of early models (arrowed) to allow removal and refitting of the fan belt
13 Engine/transmission oil and
filter renewal
2
1 Frequent oil changes are the best preventive maintenance the home mechanic can give the engine, because ageing oil becomes diluted and contaminated, which leads to premature engine wear. 2 Make sure that you have all the necessary tools before you begin this procedure. You should also have plenty of rags or newspapers handy, for mopping up any spills. The oil should preferably be changed when the engine is still fully warmed-up to normal operating temperature, just after a run; warm oil and sludge will flow out more easily. Take care, however, not to touch the exhaust or any other hot parts of the engine when working under the vehicle. To avoid any possibility of scalding, and to protect yourself from possible skin irritants and other harmful contaminants in used engine oils, it is advisable to wear gloves when carrying out this work. Access to the underside of the vehicle is greatly improved if the vehicle can be lifted on a hoist, driven onto ramps, or supported by axle stands. (see “Jacking and vehicle support”). Whichever method is chosen, make sure that the vehicle remains level, or if it is at an angle, that the drain point is at the lowest point.
Oil draining
3 Position the draining container under the drain plug on the side of the transmission casing, and unscrew the plug (see illustration). If possible, try to keep the plug pressed into the sump while unscrewing it by hand the last couple of turns.
4 Allow the oil to drain into the container (see Haynes Hint), and check the condition of the
plug’s sealing washer; renew it if worn or damaged. Also wipe off any metal particles that may have accumulated on the magnet. 5 Allow some time for the old oil to drain, noting that it may be necessary to reposition the container as the oil flow slows to a trickle; when the oil has completely drained, wipe clean the drain plug and its threads in the transmission and refit the plug, tightening it to the specified torque.
Oil filter renewal
6 The oil filter is located underneath the dynamo or alternator on the forward-facing side of the engine. On early manual transmission models the filter is of the disposable cartridge type contained within an aluminium bowl. On later models a throwaway canister is used. All automatic transmission models utilise the cartridge type filter. To renew the filter proceed as follows.
Cartridge type
7 Reposition the draining container under the
oil filter then undo and remove the long centre bolt securing the bowl to the housing (see illustration). On some models it may be advantageous to remove the grille panel, as space is rather limited. 8 With the bolts released, carefully lift away the filter bowl, which contains the filters and will also be full of oil. 9 Discard the old filter element but first make sure that the metal pressure plate has not stuck to the bottom of it. Now thoroughly clean out the filter bowl, the bolt, and the parts associated with it, using paraffin or a suitable solvent (see illustration) Dry with a lint free cloth 10 A rubber sealing ring is located in a groove round the head of the filter housing and forms an effective leak-proof joint between the housing and the filter bowl. A new rubber sealing ring is supplied with each new filter element. 11 Carefully prise out the old sealing ring from the locating groove. If the ring has become hard and is difficult to move take
great care not to damage the sides of the sealing ring groove. 12 With the old ring removed, fit the new ring in the groove at four equidistant points and press it home a segment at a time. Do not insert the ring at just one point and work round the groove pressing it home as, using this method, it is easy to stretch the ring and be left with a small loop of rubber which will not fit into the locating groove (see
illustration). 13 Reassemble the oil filter assembly by first
passing up the bolt through the hole in the bottom of the bowl, with a steel washer under the bolt’s head and a rubber or felt washer on top of the steel washer and next to the filter bowl. 14 Slide the spring over the bolt followed by the other steel washer, the remaining rubber washer and finally the filter pressure plate concave face downwards. 15 After fitting the new element to the bowl, position the bowl on the rubber sealing ring then insert and hand tighten the bolt. Before finally tightening the centre bolt, ensure that the lip of the filter bowl is resting squarely on the rubber sealing ring and is not offset or seated off the ring. If the bowl is not seating properly, rotate it until it is. Run the engine and check the bowl for leaks.
Every 6000 miles or 6 months 1•13
1
13.3 Engine/transmission oil drain plug (arrowed)
13.7 Cartridge type oil filter and retaining bolt as seen from below
13.12 Fitting a new cartridge type oil filter sealing ring
13.9 Components of the cartridge type oil filter
Keep the drain plug pressed into the sump while unscrewing it by hand the last couple of turns. As the plug releases, move it away sharply so the stream of oil issuing from the sump runs into the container, not up your sleeve!
Canister type
16 Reposition the draining container under
the oil filter then, using a suitable filter removal tool if necessary, slacken the canister initially, then unscrew it by hand the rest of the way; be prepared for some oil spillage (see illustration). Empty the oil in the old canister into the container. 17 Using a clean, lint-free rag, wipe clean the cylinder block around the filter housing. Check the old canister to make sure that the rubber sealing ring hasn’t stuck to the filter housing; if it has, carefully remove it. 18 Apply a light coating of clean engine oil to the sealing ring on the new canister. Screw the canister into position on the housing until it seats, then tighten it firmly by hand only - do
not use any tools. 19 Remove the old oil and all tools from
under the vehicle, then lower the vehicle to the ground.
Oil filling
20 Remove the dipstick and the oil filler cap from the engine. Fill the engine with oil, using the correct grade and type of oil, (see Specifications). Pour in half the specified quantity of oil first, then wait a few minutes for the oil to fall to the transmission casing. Take care during this operation, particularly in cold weather as it is all to easy to fill up the rocker cover before the oil drains down into the engine, with very messy results as it overflows out of the filler neck. Continue adding oil a small quantity at a time, until the level is up to the lower mark on the dipstick. Adding approximately 0.5 litres will raise the level to the upper mark on the dipstick. 21 Start the engine. The oil pressure warning light will take a few seconds to go out while the new filter fills with oil; do not race the engine while the light is on. Run the engine for a few minutes, while checking for leaks around the oil filter seal and the drain plug. 22 Switch off the engine, and wait a few minutes for the oil to settle in the transmission once more. With the new oil circulated and the filter now completely full, recheck the level on the dipstick, and add more oil as necessary. 23 Dispose of the used engine oil safely and in accordance with environmental regulations (see “General repair procedures”).
14 Front brake wear check
1
Warning: The dust created by wear of the shoes may contain asbestos, which is a health hazard. Never
blow it out with compressed air, and don’t inhale any of it. An approved filtering mask should be worn when working on the brakes. DO NOT use petrol or petroleum­based solvents to clean brake parts; use brake cleaner or methylated spirit only.
Drum brake models
1 After high mileage the friction linings on the brake shoes will have worn, and it will therefore be necessary to fit replacement shoes with new linings. 2 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). Remove the front roadwheels. 3 Slacken off the brake shoe adjuster(s) from behind the backplate, and then undo and remove the two brake drum retaining screws. 4 Remove the brake drum from the wheel hub. If the drum is tight, gently tap its circumference with a soft-faced mallet. 5 Brush and wipe away all traces of asbestos dust from the brake shoes, wheel cylinders and backplate, and also from the inner circumference of the brake drum. 6 Inspect the friction material and renew the brake shoes as described in Chapter 9 if they have worn down to less than the specified minimum thickness. 7 The brake shoes must also be renewed if there is any sign of hydraulic fluid contamination of the linings due to a leaking brake wheel cylinder. If this is the case, the cause of the leak must be traced and rectified before fitting new brake shoes. 8 Brake shoes should always be renewed as complete sets (four shoes to a set), otherwise uneven braking and pulling to one side may occur. 9 It is advisable to check that the brake wheel cylinders are operating correctly before proceeding further. To do this hold the brake shoes in position using two screwdrivers while an assistant very slowly depresses the brake pedal slightly. Check that the wheel cylinder pistons move out as the pedal is depressed, and return when the pedal is released. If this is not the case, it is quite likely that one of the wheel cylinder pistons is seized and the cylinder should therefore be renewed (Chapter 9).
10 Also check the condition of the brake drum, If it is deeply scored on its inner circumference it may be possible to have it skimmed at an engineering works. If the scoring is severe, renewal will be necessary
Disc brake models
11 Jack up the front or rear of the vehicle in turn, and support it on axle stands (see “Jacking and vehicle support”). 12 For better access to the brake calipers, remove the roadwheels. 13 Look through the opening in the front of the caliper, and check that the thickness of the friction lining material on each of the pads is not less than the recommended minimum thickness given in the Specifications (see Haynes Hint). If any one of the brake pads has worn down to, or below, the specified limit, all four pads must be renewed as a set (ie all the front pads).
14 For a comprehensive check, the brake pads should be removed and cleaned. The operation of the brake calipers can then be checked, and the brake discs can be fully examined. Refer to Chapter 9 for details.
15 Driveshaft gaiter check
1
With the vehicle raised and securely supported on stands (see “Jacking and vehicle support”), turn the steering onto full lock, then slowly rotate the roadwheel. Inspect the condition of the outer constant velocity (CV) joint rubber gaiters, squeezing the gaiters to open out the folds. Check for signs of cracking, splits or deterioration of the rubber, which may allow the grease to escape, and lead to water and grit entry into the joint. Also check the security and condition of the retaining clips. Repeat these checks on the inner CV joints where offset sphere type joints are fitted. If any damage or deterioration is found, the gaiters should be renewed as described in Chapter 8.
At the same time, check the general condition of the CV joints themselves by first holding the
1•14 Every 6000 miles or 6 months
13.16 Canister type oil filter
1 Housing 2 Sealing ring
3 Filter
Look through the opening in the caliper and check the thickness of the friction lining material on the brake pads
driveshaft and attempting to rotate the wheel. Repeat this check by holding the inner joint and attempting to rotate the driveshaft. Any appreciable movement indicates wear in the joints, wear in the driveshaft splines, or a loose driveshaft retaining nut.
16 Steering and suspension
lubrication
1
1 Unlike most modern cars, there are a number of steering and suspension joints on the Mini which require regular attention. Provision for lubrication of these joints is by means of a grease nipple, to which a grease gun can be engaged. The grease nipples are located in the following areas (see illustrations):
a) Steering swivel hub; two nipples, one
upper and one lower on each side.
b) Upper suspension arm inner pivot; one
nipple on each arm.
c) Rear radius arm pivot; one nipple on each
pivot. Remove the rubber blanking plug to expose the nipple on early models.
2 When lubricating the front grease nipples it is preferable to raise the front of the car and support it on axle stands (see “Jacking and vehicle support”) so that the load is taken off the suspension. This will allow the grease to penetrate into the joints more effectively. The rear radius arm pivots can be lubricated with the car on its roadwheels if wished. 3 With the car raised and suitably supported, wipe clean the area all round the grease nipple and the nipple itself. Engage the head of a grease gun, filled with the specified grease, squarely onto the nipple, keeping it pushed fully home. Operate the gun until grease can be seen to appear from under the dust cover over the joint or from around the side of the pivot bushes. 4 When lubricating the rear radius arm pivots, a generous amount of grease will be needed each side, quite a bit more than was required for the front suspension joints. It probably won’t be possible to tell when sufficient has been applied, unless you look underneath at the inner attachment on the subframe, it may be possible to see it appear around the inner pivot; add a bit more if in doubt .This is a vitally important area on the Mini and it must be well lubricated.
5 Although not actually part of the steering and suspension, the handbrake cable guides and the moving sectors on the rear subframe should be lubricated at this time to ensure smooth operation. There are no grease nipples, so the grease should be applied with a wooden spatula or similar tool to lubricate these areas thoroughly.
17 Rear brake wear check
1
The procedure for checking the rear brake components is the same as described in Section 14 for models with drum brakes.
18 Underbonnet check for fluid
leaks and hose condition
1
General
1 High temperatures in the engine compartment can cause the deterioration of the rubber and plastic hoses used for engine, accessory and emission systems operation. Periodic inspection should be made for cracks, loose clamps, material hardening and leaks. 2 Carefully check the large top and bottom radiator hoses, along with the other smaller­diameter cooling system hoses and metal pipes; do not forget the heater hoses/pipes which run from the engine to the bulkhead. Inspect each hose along its entire length, replacing any that are cracked, swollen or shows signs of deterioration. Cracks may become more apparent if the hose is squeezed (see Haynes Hint). 3 Make sure that all hose connections are tight. If the spring clamps that are used to secure some of the hoses appear to be slackening, they should be renewed to prevent the possibility of leaks. 4 Some other hoses are secured to their fittings with screw type clips. Where screw type clips are used, check to be sure they haven’t slackened, allowing the hose to leak. If clamps or screw type clips aren’t used,
make sure the hose has not expanded and/or hardened where it slips over the fitting, allowing it to leak. 5 Check all fluid reservoirs, filler caps, drain plugs and fittings etc, looking for any signs of leakage of oil, transmission and/or brake hydraulic fluid or coolant. If the vehicle is regularly parked in the same place, close inspection of the ground underneath it will soon show any leaks. As soon as a leak is detected, its source must be traced and rectified. Where oil has been leaking for some time, it is usually necessary to use a steam cleaner, pressure washer or similar, to clean away the accumulated dirt, so that the exact source of the leak can be identified.
Vacuum hoses
6 It’s quite common for vacuum hoses, especially those in the emissions system, to be numbered or colour-coded, or to be identified by coloured stripes moulded into them. Various systems require hoses with different wall thicknesses, collapse resistance and temperature resistance. When renewing hoses, be sure the new ones are made of the same material. 7 Often the only effective way to check a hose is to remove it completely from the vehicle. If more than one hose is removed, be sure to label the hoses and fittings to ensure correct installation. 8 When checking vacuum hoses, be sure to include any plastic T-fittings in the check.
Every 6000 miles or 6 months 1•15
1
16.1a Lubricating the swivel hub upper grease nipple . . .
16.1b . . . the upper suspension arm inner pivot grease nipple . . .
16.1c . . . and the rear radius arm pivot grease nipple
A leak in the cooling system will usually show up as white or rust coloured deposits on the area adjoining the leak
Inspect the fittings for cracks, and check the hose where it fits over the fitting for distortion, which could cause leakage. 9 A small piece of vacuum hose can be used as a stethoscope to detect vacuum leaks. Hold one end of the hose to your ear, and probe around vacuum hoses and fittings, listening for the “hissing” sound characteristic of a vacuum leak.
Warning: When probing with the vacuum hose stethoscope, be very careful not to come into contact with moving engine
components such as the fan or fan belt.
Fuel hoses
Warning: Before carrying out the following operation, refer to the precautions given in “Safety
first!” at the beginning of this manual, and follow them implicitly. Petrol is a highly dangerous and volatile liquid, and the precautions necessary when handling it cannot be overstressed.
10 Check all fuel hoses for deterioration and chafing. Check especially for cracks in areas where the hose bends, and also just before fittings, such as where a hose attaches to the carburettor. 11 Spring-type clamps are commonly used on fuel lines. These clamps often lose their tension over a period of time, and can be “sprung” during removal. Replace all spring­type clamps with screw clips whenever a hose is replaced.
Metal lines
12 Sections of metal piping are often used for fuel line between the fuel tank, filter and the engine. Check carefully to be sure the piping has not been bent or crimped, and that cracks have not started in the line. 13 If a section of metal fuel line must be renewed, only seamless steel piping should be used, since copper and aluminium piping don’t have the strength necessary to withstand normal engine vibration. 14 Check the metal brake lines where they enter the master cylinder for cracks in the lines or loose fittings. Any sign of brake fluid leakage calls for an immediate and thorough inspection of the brake system.
19 Fuel system components,
checks and lubrication
1
1 Sparingly apply a few drops of light oil to the throttle spindles, accelerator cable and the pedal pivot. Similarly lubricate the exposed ends of the choke cable (where fitted). 2 Check that there is a small amount of slackness in the cable so that the throttle linkage closes fully with the accelerator pedal released. Also check that full throttle can be obtained with the accelerator pedal fully depressed. 3 If there is any doubt about the cable adjustment, refer to the relevant Parts of
Chapter 4 for the full adjustment procedure. 4 On carburettor models, unscrew the piston damper cap from the top of the carburettor dashpot (see illustration) . Top up the damper with engine oil until the level is 13.0 mm above the top of the hollow piston rod. 5 Slowly push the damper back into the piston and screw on the cap taking care not to cross-thread it.
20 Contact breaker points
check and adjustment
3
Refer to Chapter 5B.
21 Distributor lubrication
1
1 It is important that the distributor cam is lightly lubricated with general purpose grease, and that the contact breaker arm, centrifugal advance weights and cam spindle are also very lightly lubricated. 2 Great care should be taken not to use too much lubricant, as any excess that might find its way onto the contact breaker points could cause burning and misfiring. 3 If an ignition shield is fitted over the front of the engine, release the three plastic retaining lugs and lift away the shield. Detach the two spring clips or undo the two screws securing the distributor cap to the distributor body and lift off the cap. 4 To gain access to the cam spindle, lift away the rotor arm. Drop no more than two drops of
engine oil onto the felt pad or screw head (see illustration). This will run down the spindle when the engine is hot and lubricate the bearings. The centrifugal advance weights can be lubricated by dropping two or three drops of engine oil through one of the holes or slots in the distributor baseplate. No more than one drop of oil should be applied to the contact breaker arm pivot post. 5 Refit the rotor arm, distributor cap and ignition shield on completion.
22 Clutch return stop
adjustment
1
Note: As friction linings of the clutch disc wear, the distance between the clutch release bearing and the clutch thrust plate will decrease. The pressure plate will then move in closer to the clutch disc to compensate for wear. Unless the wear is taken up by adjustment of the stop located between the flywheel housing and the
1•16 Every 6000 miles or 6 months
19.4 Top up the piston damper on carburettor models
21.4 Distributor lubrication points
1 Contact breaker cam 2 Contact breaker pivot post
3 Centrifugal weights lubrication point 4 Cam spindle
operating lever, the clutch will start to slip. On later models fitted with the verto type clutch, the assembly is self-adjusting and the following procedure will not be necessary.
1 To carry out the adjustment, first disconnect the clutch operating lever return spring. 2 Pull the operating lever away from the engine until all the free play is eliminated. 3 Hold the lever in this position and measure the gap between the lever and the head of the stop using feeler blades (see illustration). 4 If necessary, slacken the locknut and adjust the stop bolt until the specified gap is achieved. Then tighten the locknut.
23 Dynamo check and
lubrication
1
Dynamo checks and lubrication consist simply of checking the fan belt condition and tension (Section 8) and adding a few drops of engine oil to the dynamo rear bearing lubricating hole.
24 Control box cleaning and
inspection
1
On dynamo equipped models, remove the control box cover and check the cut-out and regulator contacts. If they are dirty or rough or burnt, place a piece of fine glasspaper (do not use emery paper or carborundum paper) between the cut-out contacts, close them manually, and draw the glasspaper through several times.
Clean the regulator contacts in exactly the same way, but use emery or carborundum paper and not glasspaper. Carefully clean both sets of contacts from all traces of dust with a rag moistened in methylated spirit. Refit the cover on completion.
25 Ignition timing check and
adjustment
3
Refer to Chapter 5B.
26 Carburettor idle speed and
mixture adjustment
3
Refer to Chapter 4A.
27 Door, boot and bonnet
check and lubrication
1
1 Check that the doors, bonnet and boot lid close securely. Check that the bonnet safety
catch operates correctly. Check the operation of the door check straps. 2 Lubricate the hinges, door check straps, the striker plates and the bonnet catch sparingly with a little oil or grease. 3 If any of the doors, bonnet or boot lid do not close effectively or appear not to be flush with the surrounding panels, carry out the adjustment procedures contained in Chapter 11.
28 Bodywork, paint and exterior
trim check
1
1 The best time to carry out this check is after the car has been washed so that any surface blemish or scratch will be clearly evident and not hidden by a film of dirt. 2 Starting at one front corner check the paintwork all around the car, looking for minor scratches or more serious dents. Check all the trim and make sure that it is securely attached over its entire length. 3 Check the security of all door locks, door mirrors, badges, bumpers, front grille and wheel trim. Anything found loose, or in need of further attention should be done with reference to the relevant Chapters of this manual. 4 Rectify any problems noticed with the paintwork or body panels (see Chapter 11).
29 Road test
1
Check the operation and performance of the braking system
1 Make sure that the vehicle does not pull to one side when braking, and that the wheels do not lock when braking hard. 2 Check that there is no vibration through the steering when braking. 3 Check that the handbrake operates correctly, without excessive movement of the lever, and that it holds the vehicle stationary on a slope. 4 With the engine switched off, test the operation of the brake servo unit (where fitted)
as follows. Depress the footbrake four or five times to exhaust the vacuum, then start the engine. As the engine starts, there should be a noticeable “give” in the brake pedal as vacuum builds up. Allow the engine to run for at least two minutes, and then switch it off. If the brake pedal is now depressed again, it should be possible to detect a hiss from the servo as the pedal is depressed. After about four or five applications, no further hissing should be heard, and the pedal should feel considerably harder.
Steering and suspension
5 Check for any abnormalities in the steering, suspension, handling or road “feel”. 6 Drive the vehicle, and check that there are no unusual vibrations or noises. 7 Check that the steering feels positive, with no excessive sloppiness or roughness, and check for any suspension noises when cornering and driving over bumps.
Drivetrain
8 Check the performance of the engine, transmission and driveline. 9 Check that the engine starts correctly, both when cold and when hot. 10 Listen for any unusual noises from the engine and transmission. 11 Make sure that the engine runs smoothly when idling, and that there is no hesitation when accelerating. 12 On manual transmission models, check that all gears can be engaged smoothly without noise, and that the gear lever action is not abnormally vague or “notchy”. 13 On automatic transmission models, make sure that the drive seems smooth without jerks or engine speed “flare-ups”. Check that all the gear positions can be selected with the vehicle at rest.
Clutch
14 Check that the clutch pedal moves smoothly and easily through its full travel, and that the clutch itself functions correctly, with no trace of slip or drag. If the movement is uneven or stiff in places, check the system components with reference to Chapter 6.
Instruments and electrical equipment
15 Check the operation of all instruments and electrical equipment. 16 Make sure that all instruments read correctly, and switch on all electrical equipment in turn, to check that it functions properly. 17 Test the operation of the brake failure warning system (where fitted) by pressing the test switch located next to the heated rear window switch. When pressed, the switch should light and go out when released. 18 If the light should come on when driving, the brake fluid level should be checked (and topped up, if necessary), as soon as possible.
Every 6000 miles or 6 months 1•17
1
22.3 Using feeler blades to measure the clutch return stop clearance
30.13b Lift off the lid and remove the element
30 Air cleaner element renewal
1
Carburettor models except Cooper S
1 On models with an air intake duct over the top of the engine, unscrew the two nuts securing the duct to the rocker cover studs. Release the clip and disconnect the duct from the air cleaner body. 2 Undo and remove the single wing nut and washer on early models, or the twin wing bolts and washers on later models, securing the air cleaner to the carburettor 3 If the air cleaner is retained by a single wing nut lift off the air cleaner top cover. Detach the rocker cover hose, then lift the air cleaner body off the carburettor, tip it up at the front and slide it sideways until it is clear of the long retaining stud and can be lifted away. Recover the sealing ring. 4 If the air cleaner is retained by two wing nuts, detach the hot air duct (where fitted) and then lift the air cleaner body off the carburettor. 5 With the air cleaner removed from the engine, recover the rubber sealing ring if it stayed behind on the carburettor flange. 6 Lift off the air cleaner cover and withdraw the paper element. On the later type moulded plastic air cleaners the cover is removed by prising it off with a screwdriver inserted in the slots on the periphery of the cover (see
illustrations). 7 Thoroughly clean the inside of the air
cleaner body. 8 Refit the air cleaner and element using a reverse of the removal procedure. Make sure that where an alignment arrow is stamped on the top cover, it is pointing toward the location lug on the air cleaner body (see illustration). Ensure also that the rubber sealing ring is in position before refitting the air cleaner. 9 If the air cleaner body incorporates an adjustable air intake spout, this should be positioned adjacent to the exhaust manifold in winter and away from it in summer.
Cooper S carburettor models
10 Undo and remove the two wing bolts and washers and lift off the air cleaner top cover. Lift out the paper elements and thoroughly clean the inside of the air cleaner body. 11 The air cleaner body may be removed if necessary after disconnecting the engine breather pipe and the throttle return spring. Take care not to lose the two rubber sealing washers from the carburettor flanges. 12 Refitting the air cleaner and elements is the reverse of the removal procedure.
Fuel injection models
13 Release the four retaining clips, then slacken and remove the three screws securing the air cleaner assembly to the throttle body, and lift off the air cleaner lid. Remove the filter element (see illustrations). 14 Wipe the body of the air cleaner clean, then fit the new element, ensuring that it is correctly seated. 15 Refit the air cleaner lid, and secure it in position with the retaining screws (tightening them securely) and clips.
31 Valve clearance adjustment
2
Refer to Chapter 2A.
32 Distributor cap, rotor arm
and HT lead check
1
Warning: Voltages produced by an electronic ignition system are considerably higher than those
produced by conventional ignition systems. Extreme care must be taken when working on the system if the ignition is switched on. Persons with surgically-implanted cardiac pacemaker devices should keep well clear of the ignition circuits, components and test equipment.
1 The spark plug (HT) leads should be inspected one at a time, to prevent mixing up the firing order, which is essential for proper engine operation. Gain access to the leads and disconnect them as described for the spark plug check and renewal. 2 Check inside the boot for corrosion, which will look like a white crusty powder. Clean this off as much as possible; if it is excessive, or if cleaning leaves the metal connector too badly corroded to be fit for further use, the lead must be renewed. Push the lead and boot back onto the end of the spark plug. The boot should fit tightly onto the end of the plug - if it doesn’t, remove the lead and use pliers carefully to crimp the metal connector inside the boot until the fit is snug. 3 Using a clean rag, wipe the entire length of the lead to remove built-up dirt and grease.
1•18 Every 12 000 miles or 12 months
30.6b . . . and lift out the element30.6a Prise off the later type air cleaner
moulded plastic cover . . .
30.8 Make sure the alignment arrow is toward the lug on the air cleaner body
30.13a On fuel injection models, release the clips (three arrowed) and remove the
screws
Once the lead is clean, check for burns, cracks and other damage. Do not bend the lead sharply, because the conductor might break. 4 Inspect the remaining spark plug (HT) leads, ensuring that each is securely fastened at the distributor cap and spark plug when the check is complete. If any sign of arcing, severe connector corrosion, burns, cracks or other damage is noticed, obtain new spark plug (HT) leads, renewing them as a set.
5 Spring back the retaining clips or undo the two screws and remove the distributor cap. Thoroughly clean it inside and out with a dry lint-free rag. 6 Examine the HT lead segments inside the cap. If they appear badly burned or pitted renew the cap. Also check the carbon brush in the centre of the cap, ensuring that it is free to move and stands proud of its holder. Make sure that there are no signs of cracks or black “tracking” lines running down the inside of the cap, which will also mean renewal if evident. 7 Inspect the rotor arm checking it for security and also for signs of deterioration as described above.
8 Refit the distributor cap on completion.
33 Spark plug renewal
1
1 It is vital for the correct running, full performance and proper economy of the engine that the spark plugs perform with maximum efficiency. The most important factor in ensuring this, is that the plugs fitted are appropriate for the engine (a suitable type is specified at the end of this Chapter). If this type is used and the engine is in good condition, the spark plugs should not need attention between scheduled renewal intervals. Spark plug cleaning is rarely
necessary, and should not be attempted unless specialised equipment is available, as damage can easily be caused to the firing ends. 2 Spark plug removal and refitting requires a spark plug socket, with an extension which can be turned by a ratchet handle or similar. This socket is lined with a rubber sleeve, to protect the porcelain insulator of the spark plug, and to hold the plug while you insert it into the spark plug hole. You will also need a wire-type feeler gauge, to check and adjust the spark plug electrode gap, and a torque wrench to tighten the new plugs to the specified torque. 3 To remove the spark plugs, open the bonnet, where fitted, release the three plastic retaining lugs and lift the ignition shield off the front of the engine 4 If the marks on the original-equipment HT leads cannot be seen, mark the leads 1 to 4, to correspond to the cylinder the lead serves. 5 Pull the leads from the plugs by gripping the rubber boot, not the lead, otherwise the lead connection may be fractured (see
illustration). 6 Unscrew the spark plugs, ensuring that the
socket is kept in alignment with each plug - if the socket is forcibly moved to either side, the porcelain top of the plug may be broken off. If any undue difficulty is encountered when unscrewing any of the spark plugs, carefully check the cylinder head threads and sealing surfaces for signs of wear, excessive corrosion or damage; if any of these conditions is found, seek the advice of a dealer as to the best method of repair. 7 As each plug is removed, examine it as follows - this will give a good indication of the condition of the engine. If the insulator nose of the spark plug is clean and white, with no deposits, this is indicative of a weak mixture. 8 If the tip and insulator nose are covered with hard black-looking deposits, then this is indicative that the mixture is too rich. Should the plug be black and oily, then it is likely that the engine is fairly worn, as well as the mixture being too rich. 9 If the insulator nose is covered with light tan to greyish-brown deposits, then the mixture is
correct, and it is likely that the engine is in good condition. 10 The spark plug electrode gap is of considerable importance as, if it is too large or too small, the size of the spark and its efficiency will be seriously impaired. The gap should be set to the value given in the Specifications. 11 To set the electrode gap, measure the gap with a feeler blade or adjusting tool, and then bend open, or closed, the outer plug electrode until the correct gap is achieved (see illustration). The centre electrode should never be bent, as this may crack the insulation and cause plug failure, if nothing worse. If the outer electrode is not exactly over the centre electrode, bend it gently to align them. 12 Before fitting the spark plugs, check that the threaded connector sleeves at the top of the plugs are tight, and that the plug exterior surfaces and threads are clean (see Haynes
Hint). 13 On installing the spark plugs, first check
that the cylinder head thread and sealing surface are as clean as possible; use a clean rag wrapped around a paintbrush to wipe clean the sealing surface. Ensure that the spark plug threads are clean and dry then screw them in by hand where possible. Take extra care to enter the plug threads correctly. 14 When each spark plug is started correctly on its threads, screw it down until it just seats lightly, then tighten it to the specified torque wrench setting. 15 Reconnect the HT leads in their correct order, using a twisting motion on the boot until it is firmly seated. Finally, refit the ignition shield.
Every 12 000 miles or 12 months 1•19
1
33.5 Pull the leads off the spark plugs by gripping the rubber boot
33.11 Adjusting a spark plug electrode gap
It is very often difficult to insert spark plugs into their holes without cross­threading them. To avoid this possibility, fit a short length of 5/16 inch internal diameter rubber hose over the end of the spark plug. The flexible hose acts as a universal joint to help align the plug with the plug hole. Should the plug begin to cross-thread, the hose will slip on the spark plug, preventing thread damage to the aluminium cylinder head
If new spark plug leads are to be fitted, remove the leads one at a time and fit each new lead in exactly the
same position as the old one.
34 Emission control equipment
check
1
1 Of the emission control systems that may be fitted, only the air pump drivebelt (where
applicable), the crankcase ventilation system and the evaporative emission control systems require regular checking, and even then, the components of these systems require minimal attention. 2 Checks and adjustment of the air pump drivebelt are contained in Section 9. 3 The crankcase ventilation system filter in
the oil filler cap should be renewed by simply renewing the cap (the new cap is supplied with filter inside). Checks of the other system components are contained in Chapter 4C. 4 Should it be felt that the other systems are not functioning correctly, the advice of a dealer should be sought.
35 Coolant renewal
2
Warning: Wait until the engine is cold before starting this procedure. Do not allow
antifreeze to come into contact with your skin, or with painted surfaces of the vehicle. Rinse off spills immediately with plenty of water. Never leave antifreeze lying around in an open container, or in a puddle in the driveway or on the garage floor. Children and pets are attracted by its sweet smell, but antifreeze can be fatal if ingested.
Note: If coolant to Rover specification, in the correct ratio, has been continuously maintained in the system, then coolant renewal will not normally be necessary. However, to be absolutely sure about the integrity of the antifreeze and anti-corrosion properties of the coolant, periodic renewal is to be recommended.
Cooling system draining
1 To drain the system, first remove the expansion tank filler cap (see “Weekly checks”). Move the heater temperature control to the hot position.
2 If there is anti-freeze in the system, place clean bowls beneath the radiator and at the rear of the engine to collect the coolant for re-use. 3 Undo and remove the radiator drain plug and cylinder block drain plug, and allow the coolant to drain. If fitted, the radiator drain plug is located at the bottom of the radiator nearest the grille, and the cylinder block drain plug (if fitted) can be found at the rear of the block, beneath the engine tie-bar (see
illustration). 4 On later models the radiator does not
incorporate a drain plug, and it is therefore necessary to detach the bottom hose to drain the coolant. To do this slacken the bottom hose retaining clip and pull the hose off the radiator outlet. The hose clip is very inaccessible and a long thin screwdriver is quite useful here. If the hose proves difficult to remove from the radiator outlet, it is possible to gently push it off from the access hole under the wheel arch. 5 When the coolant has stopped running, probe the orifices, particularly the cylinder block orifice, with a short piece of wire to dislodge any particles of rust or sediment which may be preventing the coolant from completely draining out.
Cooling system flushing
6 With time, the cooling system may
gradually lose its efficiency if the radiator core becomes choked with rust, scale deposits from the water, and other sediment. This is especially likely if an inferior grade of antifreeze has been used that has not been regularly renewed. To minimise this, as well as using only the specified type of antifreeze and clean soft water, the system should be flushed as follows whenever any part of it is disturbed, and/or when the coolant is renewed. 7 With the coolant drained, close the drain taps and refill the system with fresh water. Refit the radiator cap, start the engine and warm it up to normal operating temperature, then stop it and (after allowing it to cool down completely) drain the system again. Repeat as necessary until only clean water can be seen to emerge, then refill finally with the specified coolant mixture. 8 If only clean, soft water and good-quality antifreeze has been used, and the coolant has been renewed at the specified intervals, the above procedure will be sufficient to keep the system clean for a considerable length of time. If, however, the system has been neglected, a more thorough operation will be required, as follows. 9 To flush the system first drain the coolant as described in the previous Section. Place a garden hose in the radiator filler cap neck and allow water to run through the system for ten to fifteen minutes. 10 To flush the engine, remove the thermostat (see Chapter 3), insert the garden hose into the thermostat housing, and allow water to circulate until it runs clear from the bottom hose. If, after a reasonable period, the water still does not run clear, the radiator should be flushed with a good proprietary cleaning agent. 11 In severe cases of contamination, reverse-flushing of the radiator may be necessary. To do this, remove the radiator (see Chapter 3), invert it, and insert the garden hose into the bottom outlet. Continue flushing until clear water runs from the top hose outlet. A similar procedure can be used to flush the heater matrix. 12 The use of chemical cleaners should be necessary only as a last resort. Normally, regular renewal of the coolant will prevent excessive contamination of the system.
1•20 Every 12 000 miles or 12 months
Every 24 000 miles or 24 months
35.3 Cylinder block coolant drain tap or plug location (arrowed)
Cooling system filling
13 Refit the cylinder block and radiator drain plugs or bottom hose connection as applicable. 14 Prepare a sufficient quantity of coolant mixture (water and antifreeze), in the specified concentration, to allow for a surplus, so as to have a reserve supply for topping-up. Note:
On models with no cylinder block drain plug, it is not possible to fully drain the coolant. To
establish a suitable antifreeze concentration it will be necessary to pour adequate antifreeze directly into the radiator and then top-up with water. Subsequent topping-up should be done with an antifreeze/water mixture. 15 Set the heater control knob to the maximum heat position and then fill the cooling system slowly. Slow filling reduces the possibility of air being trapped and forming air-locks. It helps also, if the large radiator hoses are gently squeezed during the filling procedure. 16 Do not fill the system higher than within 12 mm of the filler orifice. Overfilling will merely result in coolant loss down the overflow pipe due to expansion. 17 When the system is full, refit the filler cap and turn it firmly clockwise to lock it in position. Start the engine and run it at idle speed, until it has warmed-up to normal operating temperature. 18 Stop the engine, allow it to cool down completely (overnight, if possible), then remove the radiator filler cap and top-up if necessary. Refit the filler cap, tightening it securely, and wash off any spilt coolant from the engine compartment and bodywork. 19 After refilling, always check carefully all components of the system (but especially any unions disturbed during draining and flushing) for signs of coolant leaks. Fresh antifreeze has a searching action, which will rapidly expose any weak points in the system.
36 Brake fluid renewal
3
Warning: Brake hydraulic fluid can harm your eyes and damage painted surfaces, so use
extreme caution when handling and pouring it. Do not use fluid that has been standing open for some time as it absorbs moisture from the air. Excess moisture can cause a dangerous loss of braking effectiveness.
The procedure is similar to that for the bleeding of the hydraulic system as described in Chapter 9, except that the brake fluid reservoir should be emptied by siphoning, and allowance should be made for the old fluid to be removed from the circuit when bleeding a section of the circuit.
37 Fuel filter renewal (fuel
injection models)
3
Warning: Before carrying out the following operation, refer to the precautions given in “Safety
first!” at the beginning of this manual, and follow them implicitly. Petrol is a highly dangerous and volatile liquid, and the precautions necessary when handling it cannot be overstressed.
1 Disconnect the battery negative lead. 2 Chock the front wheels then jack up the
rear of the car and support it on axle stands (see “Jacking and vehicle support”).
3 To minimise fuel loss during the following operation, working inside the luggage compartment, remove the top stud, then pivot the fuel tank trim panel downwards and fit a hose clamp to the fuel tank feed hose. 4 Refer to the information on fuel system depressurisation contained in Chapter 4B, Section 6. 5 From underneath the vehicle, slacken the union nuts and disconnect the inlet and outlet pipes from the fuel filter, whilst retaining the union adapter/filter with an open-ended spanner (see illustrations). 6 Remove the two bolts securing the filter mounting bracket to the subframe, and remove the filter assembly from the car. 7 Slacken and remove the outlet pipe adapter and O-ring from the filter, then slacken the clamp bolt and slide the filter out of the mounting bracket, noting which way the arrow stamped on the filter is pointing. 8 Remove the plugs from the filter, then fit the outlet pipe adapter (using a new O-ring), and tighten it securely. Ensuring that the arrow is pointing in the direction of the flow of fuel, slide the filter into position in the mounting bracket, and securely tighten the clamp bolt. 9 Refit the filter assembly to the car, tightening its mounting bolts securely. 10 Refit the inlet and outlet pipes to the filter, and securely tighten their union nuts. 11 Lower the car to the ground, then remove the clamp from the fuel tank feed hose, and secure the trim panel in position with its retaining stud. Reconnect the battery, then start the engine and check the filter unions for leakage.
Warning: Dispose of the old filter safely; it will be highly flammable and may explode if thrown on a fire.
Every 24 000 miles or 24 months 1•21
1
37.5a Fuel filter inlet union “A”, outlet union “B” and mounting bracket retaining bolts “C”
37.5b Slacken the union nuts whilst retaining the union adapter/filter with an open-ended spanner
Old hydraulic fluid is invariably much darker in colour than the new, making it easy to distinguish between the two.
2A
Chapter 2 Part A:
Engine in-car repair procedures
Engine general
Code and displacement:
85H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 848 cc
99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 998 cc
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1098 cc
12H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1275 cc
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1275 cc
Bore:
85H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.94 mm
99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.59 mm
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.59 mm
12H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70.61 mm
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70.61 mm
Stroke:
85H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68.25 mm
99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76.20 mm
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.72 mm
12H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81.28 mm
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81.28 mm
Compression ratio:
85H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3:1
99H:
Pre-1983 manual transmission models . . . . . . . . . . . . . . . . . . . . . 8.3:1
1983 to 1987 manual transmission models . . . . . . . . . . . . . . . . . . 10.3:1
Automatic transmission models . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.9:1
1988-on (category C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.6:1
1989-on (low compression) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3:1
1989-on (high compression) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.6:1
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5:1
12H:
1275 GT models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.8:1
Cooper S Mk III models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.75:1
12A:
Cooper models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.0:1
All other models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4:1
Direction of crankshaft rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Clockwise (viewed from left-hand side of vehicle)
Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3-4-2 (No 1 cylinder next to radiator)
Compression test - description and interpretation . . . . . . . . . . . . . . 2
Cylinder head (carburettor engines) - removal and refitting . . . . . . . 7
Cylinder head (fuel injection engines) - removal and refitting . . . . . . 8
Distributor driveshaft - removal and refitting . . . . . . . . . . . . . . . . . . . 13
Engine oil level check . . . . . . . . . . . . . . . . . . . . . .See “Weekly Checks”
Engine/transmission mountings - renewal . . . . . . . . . . . . . . . . . . . . 12
Flywheel (manual transmission models) - removal and refitting . . . . 10
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Oil cooler - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Oil filter housing and delivery pipe - removal and refitting . . . . . . . . 15
Oil pressure relief valve - removal, inspection and refitting . . . . . . . . 14
Rocker shaft assembly - removal, inspection and refitting . . . . . . . . 6
Timing chain, tensioner and sprockets - removal, inspection and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Top Dead Centre (TDC) for number one piston - locating . . . . . . . . . 3
Torque converter (automatic transmission models) - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Valve clearances - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2A•1
Specifications
Contents
Easy, suitable for
novice with little experience
Fairly easy, suitable for beginner with some experience
Fairly difficult,
suitable for competent DIY mechanic
Difficult, suitable for experienced DIY mechanic
Very difficult,
suitable for expert DIY or professional
Degrees of difficulty
5
4
3
2
1
Valve clearances
Inlet and exhaust (engine cold):
All engine types except 12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 mm
12A engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.33 to 0.38 mm
Torque wrench settings Nm lbf ft
Cylinder head nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 50
Rocker shaft pedestal nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 24
Crankshaft pulley bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 75
Camshaft nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 65
Torque converter centre bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 112
Torque converter (six central bolts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 21
Timing cover and front plate:
1
4 in UNF bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5
5
16 in UNF bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 12
Rocker cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 3.5
Engine mountings:
3
8 in UNC bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 30
M8 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 22
M10 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 33
M12 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 53
1 General information
How to use this Chapter
This Part of Chapter 2 describes those repair procedures that can reasonably be carried out on the engine while it remains in the car. If the engine has been removed from the car and is being dismantled as described in Part B, any preliminary dismantling procedures can be ignored.
Part B describes the removal of the engine/transmission from the vehicle, and the full overhaul procedures that can then be carried out.
Engine description
The Mini engine is a four-cylinder, water­cooled, overhead valve type of 848, 998, 1098, or 1275 cc displacement, depending on model and year of manufacture. The engine is bolted to the transmission assembly, which also forms the engine sump, and the complete power unit is supported, via rubber mountings, in the front subframe.
The cast iron cylinder head contains two valves per cylinder, mounted vertically and running in pressed-in valve guides. The valves are operated by rocker arms and pushrods via tubular cam followers from the camshaft, located in the left-hand side of the cylinder block.
The inlet and exhaust manifolds are attached to the left-hand side of the cylinder head and are linked to the valves via five inlet and exhaust ports of siamese configuration.
The pistons are of anodised aluminium alloy with three compression rings and an oil control ring on all engines except later 1275 cc units. These engines only have two compression rings. The gudgeon pin is retained in the small­end of the connecting rod by a pinch-bolt on 848 cc engines, by circlips on 1098 cc and early 998 cc engines and by an interference fit
in the connecting rod small-end bore on 1275 cc and later 998 cc engines. At the other end of the connecting rod, renewable big-end shell bearings are fitted.
At the front of the engine, a single row chain drives the camshaft via the camshaft and crankshaft sprockets. On 1275 cc Cooper S models a duplex (twin row) timing chain is fitted. On the 848 cc engine, the camshaft is supported by three bearings, two being bored directly in the cylinder block while a white metal bearing (which is renewable) is fitted at the timing chain end. On the 998 cc, 1098 cc and 1275 cc units three steel-backed metal camshaft bearings are fitted.
The statically and dynamically balanced forged steel crankshaft is supported by three renewable shell type main bearings. Crankshaft endfloat is controlled by four semi­circular thrustwashers located in pairs on either side of the centre main bearing.
A forced feed system of lubrication is used, with oil circulated round the engine from the transmission casing/sump. The level of engine oil in the sump is indicated on the dipstick, which is fitted on the right-hand side of the engine. The oil in the transmission casing/ sump is also used to lubricate the transmission and differential.
The oil pump is mounted at the end of the cylinder block and is driven by the camshaft.
Oil is drawn from the sump through a gauze screen in the oil strainer and is sucked up the pick-up pipe and drawn into the oil pump. From the oil pump it is forced under pressure along a gallery on the right-hand side of the engine, and through drillings to the big-end, main and camshaft bearings. A small hole in each connecting rod allows a jet of oil to lubricate the cylinder wall with each revolution.
From the camshaft front bearing, oil is fed through drilled passages in the cylinder block and head to the front rocker pedestal where it enters the hollow rocker shaft. Holes drilled in the shaft allow for the lubrication of the rocker arms, and the valve stems and pushrod ends.
This oil is at a reduced pressure to the oil delivered to the crankshaft bearings. Oil from the front camshaft bearing also lubricates the timing chain. Oil returns to the sump by various passages the tappets being lubricated by oil returning via the pushrod drillings in the block.
On all models a full-flow oil filter is fitted, and all oil passes through this filter before it reaches the main oil gallery. The oil is passed directly from the oil pump across the block to an external pipe on the right-hand side of the engine which feeds into the filter head. Cooper S and certain later 1275 cc models are fitted with an oil cooler.
The water pump and fan are driven together with the dynamo or alternator by a V-belt from the crankshaft pulley.
Both the distributor and oil pump are driven off the camshaft: the distributor via skew gears on the right-hand side, and the oil pump via a slotted drive or splined coupling from the rear.
Repair operations possible with the engine in the car
The following work can be carried out with the engine in the car:
a) Compression pressure - testing. b) Valve clearances - adjustment. c) Timing chain, tensioner and sprockets -
removal and refitting.
d) Rocker shaft assembly - removal and
refitting
e) Cylinder head and valve gear - removal
and refitting.
f) Cylinder head and pistons -
decarbonising. g) Crankshaft oil seals - renewal. h) Flywheel/torque converter - removal and
refitting. i) Engine mountings - renewal. j) Oil pressure relief valve - removal,
inspection and refitting. k) Oil filter housing and delivery pipe -
removal and refitting. l) Oil cooler - removal and refitting
2A•2 Engine in-car repair procedures
2 Compression test -
description and interpretation
2
1 When engine performance is down, or if misfiring occurs which cannot be attributed to the ignition or fuel systems, a compression test can provide diagnostic clues as to the engine’s condition. If the test is performed regularly, it can give warning of trouble before any other symptoms become apparent. 2 The engine must be fully warmed-up to normal operating temperature, the battery must be fully charged, and all the spark plugs must be removed (Chapter 1). The aid of an assistant will also be required. 3 Disable the ignition system by disconnecting the ignition coil HT lead from the distributor cap and earthing it on the cylinder block. Use a jumper lead or similar wire to make a good connection. 4 Fit a compression tester to the No 1 cylinder spark plug hole - the type of tester which screws into the plug thread is to be preferred. 5 Have the assistant hold the throttle wide open, and crank the engine on the starter motor; after one or two revolutions, the compression pressure should build up to a maximum figure, and then stabilise. Record the highest reading obtained. 6 Repeat the test on the remaining cylinders, recording the pressure in each. 7 All cylinders should produce very similar pressures; a difference of more than 2 bars between any two cylinders indicates a fault. Note that the compression should build up quickly in a healthy engine; low compression on the first stroke, followed by gradually­increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes,
indicates leaking valves or a blown head gasket (a cracked head could also be the cause). Deposits on the undersides of the valve heads can also cause low compression. 8 If the pressure in any cylinder is low, carry out the following test to isolate the cause. Introduce a teaspoonful of clean oil into that cylinder through its spark plug hole, and repeat the test. 9 If the addition of oil temporarily improves the compression pressure, this indicates that bore or piston wear is responsible for the pressure loss. No improvement suggests that leaking or burnt valves, or a blown head gasket, may be to blame. 10 A low reading from two adjacent cylinders is almost certainly due to the head gasket having blown between them; the presence of coolant in the engine oil will confirm this. 11 If one cylinder is about 20 percent lower than the others and the engine has a slightly rough idle, a worn camshaft lobe could be the cause.
12 If the compression reading is unusually high, the combustion chambers are probably coated with carbon deposits. If this is the case, the cylinder head should be removed and decarbonised. 13 On completion of the test, refit the spark plugs and reconnect the ignition coil HT lead.
3 Top Dead Centre (TDC) for
number one piston - locating
1
1 Top dead centre (TDC) is the highest point in the cylinder that each piston reaches as the crankshaft turns. Each piston reaches its TDC position at the end of its compression stroke and then again at the end of its exhaust stroke. For the purpose of engine timing, TDC refers to the position of No 1 piston at the end of its compression stroke. On the engines covered by this manual, No 1 piston is at the timing chain end of the engine. It is necessary to set the engine in this position when carrying out many of the operations in this Chapter. To do so, proceed as follows. 2 Where fitted, release the three plastic retaining lugs and lift the ignition shield off the front of the engine. 3 Spring back the two distributor cap retaining clips or undo the screws then place the distributor cap to one side. 4 Gain access to the ignition timing marks by undoing the two bolts securing the inspection plate to the top of the flywheel housing and lifting off the plate. On automatic transmission models, withdraw the rubber grommet from the top of the converter housing (see illustrations). On later models there is a timing scale on the timing cover, together with a notch or pointer on the crankshaft pulley
(see illustration). 5 Turn the engine over until No 1 piston is
approaching TDC on the compression stroke.
Engine in-car repair procedures 2A•3
2A
3.4a Timing mark locations - early manual transmission models
1 Inspection cover 2 Timing marks 3 Pointer A Detail showing alternative
timing marks
B Insert screwdriver to turn
torque converter
3.4b Timing mark locations - automatic transmission models
3.4c Timing scale on timing cover of later manual transmission models
This can be checked by removing No 1 spark plug and feeling the pressure being developed in the cylinder as the piston rises, or by removing the rocker cover and noting when the valves of No 4 cylinder are rocking, ie the inlet valve just opening and the exhaust valve just closing. On manual transmission models, the engine can be turned over quite easily by engaging top gear and moving the car forwards. This should only be done on level ground; and make sure that the car cannot run away! An alternative method, and the method that should be used on automatic transmission models, is to press the fan belt midway between the water pump pulley and dynamo or alternator pulley and then turn the fan blades. Fine positioning of the torque converter can be done by inserting a screwdriver through the access hole and turning the ring gear.
6 Continue turning the engine, in the correct direction of rotation, until No 1 piston is at TDC on the compression stroke. Verify this by checking that the timing marks are aligned. The timing marks on the flywheel (or torque converter), and the pointer on the housing, can be viewed through the inspection aperture using a small mirror. The 1/4 mark on the flywheel or torque converter indicates TDC and should be aligned with the pointer in the housing. On later models with a timing scale on the timing cover, the notch in the crankshaft pulley should be aligned with the 0 pointer on the timing cover scale. 7 The distributor rotor arm should now be pointing towards the No 1 spark plug HT lead segment in the distributor cap indicating that the crankshaft is correctly positioned with number 1 cylinder at TDC on its compression stroke. Temporarily place the cap in position to verify this if necessary. If the rotor arm is pointing at the No 4 HT lead segment in the cap, rotate the crankshaft one full turn (360º) until the TDC timing marks are realigned and the rotor arm is pointing at the No 1 segment.
4 Valve clearances -
adjustment
2
1 The valve adjustments should be made with the engine cold. The importance of correct rocker arm/valve stem clearances cannot be overstressed as they vitally affect the performance of the engine. If the clearances are set too wide, the efficiency of the engine is reduced as the valves open later and close earlier than was intended. If, on the other hand the clearances are set too close there is danger that the stems will expand upon heating and not allow the valves to close properly, which will cause burning of the valve head and seat, and possible warping.
2 To gain access to the rocker arms, remove the ignition shield (where fitted) from the front of the engine then undo the two rocker cover retaining bolts. Lift out the bolts along with the ignition shield brackets and lift the rocker cover and gasket away. Collect the rocker cover retaining bolt dished washers from the top of the two rubber seals. 3 It is important that the clearance is set when the tappet of the valve being adjusted is on the heel of the cam, (ie opposite the peak). Turn the engine until valve No 8 (nearest the flywheel end of the engine) is fully open. With the engine in this position, valve No 1 will be fully closed and ready to be checked. On manual transmission models, the engine can be turned over quite easily by engaging top gear and moving the car forwards. This should only be done on level ground; and make sure that the car cannot run away! An alternative method, and the method that should be used on automatic transmission models, is to press the fan belt midway between the water pump pulley and dynamo or alternator pulley and then turn the fan blades.
4 A feeler blade of the correct thickness should now be inserted between the valve stem and rocker arm. When the clearance is correct the feeler blade should be a smooth stiff sliding fit between the valve stem and rocker arm. The correct valve clearances are given in the Specifications at the start of this Chapter. 5 If the feeler blade is a tight or loose fit then the clearance must be adjusted. To do this, loosen the locknut of the adjustment stud and screw the adjuster stud in or out until the feeler blade can be felt to drag slightly when drawn from the gap (see illustration). 6 Hold the adjuster firmly in this position and tighten the locknut. Recheck the gap on completion to ensure that it has not altered when locking the nut and stud. 7 Check each valve clearance in turn in the following sequence (which also avoids turning
the crankshaft more than necessary). The valves are numbered from the timing chain end of the engine.
Valve fully open Check and adjust
Valve No 8 Valve No 1 Valve No 6 Valve No 3 Valve No 4 Valve No 5 Valve No 7 Valve No 2 Valve No 1 Valve No 8 Valve No 3 Valve No 6 Valve No 5 Valve No 4 Valve No 2 Valve No 7
8 When all the valves have been checked and adjusted, refit the rocker cover using a new gasket and secure with the retaining bolts. Where applicable, remember to fit the ignition shield brackets with the retaining bolts. Avoid over-tightening the rocker cover bolts. 9 Refit the spark plugs, HT leads and ignition shield.
5 Timing chain, tensioner and
sprockets - removal,
inspection and refitting
3
Removal
1 Disconnect the battery negative lead. 2 Refer to Chapter 1 and remove the fan belt. 3 Refer to Chapter 3 and remove the radiator. 4 Undo the bolts securing the fan to the water
pump spindle, and remove the fan. 5 On later models, it may be necessary to remove the lower radiator mounting bracket to gain the necessary clearance to allow removal of the crankshaft pulley. To do this, undo the two nuts and bolts, accessed from underneath the wheel arch, securing the left­hand engine mounting to the subframe. Position a jack with interposed block of wood beneath the engine/transmission and carefully lift the jack until the engine/transmission is raised slightly. Undo the nuts and through­bolts securing the mounting bracket to the transmission, and remove the bracket assembly from the vehicle (see illustration). 6 Bend back the locking tab of the crankshaft pulley locking washer under the crankshaft pulley retaining bolt, prising it back with a cold
2A•4 Engine in-car repair procedures
5.5 Left-hand mounting bracket
attachment bolts (arrowed) on later
manual transmission models
4.5 Adjusting the valve clearances
Turning the engine will be easier if the spark plugs are removed first - see Chapter 1.
Turning the engine will be easier if the spark plugs are removed first - see Chapter 1.
chisel or screwdriver through the radiator grille in the wing. Using a suitable socket or spanner remove the bolt and locking washer. This bolt is sometimes very difficult to shift, and hitting the free end of the spanner with a heavy hammer is often the only way to start it. Engage top gear and apply the handbrake hard to prevent the engine from turning. Alternatively, remove the starter motor (Chapter 5A) and lock the flywheel with a screwdriver or similar tool engaged with the ring gear teeth. 7 Once the bolt has been slackened, set the engine at TDC for No 1 piston as described in Section 3. 8 Placing two large screwdrivers behind the crankshaft pulley at 180º to each other, carefully lever the pulley off. It is preferable to use a proper pulley extractor if this is available, but large screwdrivers or tyre levers are quite suitable, providing care is taken not to damage the pulley flange. 9 Remove the Woodruff key from the crankshaft nose with a pair of pliers and store it safely as it is a very small part and can easily be mislaid. 10 Unscrew the bolts holding the timing cover to the block. Note: Four of the bolts are
larger than the others and each bolt makes use of a large flat washer as well as a spring washer.
11 Take off the timing cover and gasket. If fitted, detach the engine breather hose from the cover.
12 With the timing cover removed, slide off the oil thrower. Note: The concave side faces forward. 13 Bend back the locking tab on the washer under the camshaft retaining nut and unscrew the nut, noting how the locking washer locating tag fits in the camshaft sprocket keyway (see illustration). 14 To remove the camshaft and crankshaft sprockets complete with chain, ease each sprocket forward a little at a time, levering behind each one in turn with two large screwdrivers at 180º to each other. If the sprockets are locked solid, it will be necessary to use a suitable puller. With both sprockets removed, extract the Woodruff keys from the crankshaft and camshaft with a pair of pliers and store them safely. Note that
there may be a number of very thin packing washers behind the crankshaft sprocket; if so carefully remove them. 15 On later models, unscrew the timing chain tensioner retaining bolt and remove the bolt and tensioner. Note that there is a washer on each side of the tensioner arm.
Inspection
16 Thoroughly clean all the components with paraffin or a suitable solvent and dry thoroughly. Pay particular attention to the timing cover and the mating face on the engine front plate, ensuring that all traces of old gasket are removed. 17 Examine the teeth on both the crankshaft and camshaft sprockets for wear. Each tooth forms an inverted “V” with the sprocket periphery and, if worn, the side of each tooth under tension will be slightly concave in shape when compared with the other side of the tooth. If any sign of wear is present the sprockets must be renewed. 18 Examine the links of the chain for side slackness and renew the chain if any slackness is noticeable when compared with a new chain. It is a sensible precaution to renew the chain at about 60 000 miles, and at a lesser mileage if the engine is dismantled for a major overhaul. The actual rollers on a very badly worn chain may be slightly grooved. Cooper S type engines use duplex chains. 19 Also check the rubber tension rings in the camshaft sprocket, where fitted. It is quite likely that the rubber will have become hard due to heat and oil contamination and it is advisable to renew them as a matter of course. The rings are simply prised out with a screwdriver and new rings stretched over the sprocket flanges and into the grooves (see illustration). A spring-loaded rubber tensioning pad may be fitted to the timing cover on Cooper S type and later engines in place of the tensioning rings. If the rubber pad is grooved where it bears against the chain, it should also be renewed. 20 It is advisable to renew the timing cover oil seal at this stage. Drive out the old seal and tap in the new one using the old seal to spread the load. Ensure that the open side of the seal faces inward, towards the chain.
Refitting
Note: Before reassembly begins check that the original packing washers are in place on the crankshaft nose. If new sprockets are being fitted it may be necessary to fit additional washers (see paragraph 25). These washers ensure that the crankshaft sprocket lines up correctly with the camshaft sprocket.
21 Refit the Woodruff keys in their respective slots in the crankshaft and camshaft, and ensure that they are fully seated. If their edges are burred they must be cleaned with a fine file. 22 Lay the two sprockets on a clean surface so that the timing dots are adjacent to each other. Slip the timing chain over them and pull
Engine in-car repair procedures 2A•5
2A
5.19 Fitting a new tensioning ring to the camshaft
5.13 Timing sprocket and chain assembly - later type with tensioner arm
1 Camshaft sprocket 2 Crankshaft sprocket 3 Timing chain
4 Oil thrower 5 Lockwasher 6 Nut
7 Tensioner retaining
bolt
8 Tensioner
the sprockets back into mesh with the chain so that the timing dots, although further apart are still adjacent to each other (see
illustrations). 23 Check that the engine is still positioned at
TDC for No 1 piston (Section 3). In this position the crankshaft Woodruff key should be at the 12 o’clock position and the camshaft Woodruff key should be at the 2 o’clock position. 24 Fit the timing chain and sprocket assembly onto the camshaft and crankshaft, keeping the timing marks adjacent. If the camshaft and crankshaft have been positioned accurately, it will be found that the keyways on the sprockets will match the position of the keys, although it may be necessary to rotate the camshaft a fraction to ensure accurate lining­up of the camshaft sprocket.
25 Press the sprockets into position on the crankshaft and camshaft as far as they will go.
Note: If new sprockets are being fitted they should be checked for alignment before being finally fitted to the engine. Place the sprockets
in position without the timing chain and place the straight edge of a steel ruler from the side of the camshaft gear teeth to the crankshaft sprocket and measure the gap between the steel rule and the sprocket (see illustration). If a gap exists a suitable number of packing washers must be placed on the crankshaft nose to bring the crankshaft sprocket onto the same plane as the camshaft sprocket. 26 Fit the oil thrower to the crankshaft with the concave side forward. 27 Fit the locking washer to the camshaft sprocket with its locating tab in the sprocket keyway. 28 Screw on the camshaft sprocket retaining nut and tighten securely. 29 Bend up the locking tab of the locking washer to hold the camshaft retaining nut securely. 30 On engines with a separate timing chain tensioner, refit the tensioner and retaining bolt ensuring that there is a washer on each side of the tensioner arm.
31 Generously oil the chain and sprockets. 32 Apply a bead of RTV sealant to each side
of the new gasket, on the lower half of the gasket only. Place the gasket on the timing cover then quickly position the timing cover on the engine.
33 Screw in the timing cover retaining bolts with the flat washer next to the cover flange and under the spring washer. Tighten the respective bolts to the specified torque. 34 Fit the crankshaft pulley to the nose of the crankshaft, ensuring that the keyway engages with the Woodruff key. 35 Fit the crankshaft retaining bolt locking washer and screw in the crankshaft pulley retaining bolt. Tighten to the specified torque while using the same method to prevent crankshaft rotation as was used for removal. 36 Where removed, refit the radiator lower mounting bracket and secure the bracket to the engine/transmission and subframe. Remove the jack under the engine. 37 Refit the fan to the water pump spindle and secure with the four bolts securely tightened. 38 Refit the radiator as described in Chapter 3 and the fan belt as described in Chapter 1. 39 Refit the components removed when setting the engine at TDC, then reconnect the battery.
6 Rocker shaft assembly -
removal, inspection and refitting
3
General information
1 The rocker shaft assembly is secured to the top of the cylinder head by the cylinder head inner studs and nuts. Although in theory it is possible to undo the head nuts and remove the rocker shaft assembly without removing the head, in practice, this is not recommended.
2A•6 Engine in-car repair procedures
5.22a Timing dots on sprockets aligned with chain fitted
5.22b Timing mark locations relative to keyways
1 Timing dot on camshaft sprocket 2 Timing dot on crankshaft sprocket
5.25 Timing sprocket alignment ­double row type shown
1 Camshaft sprocket 2 Woodruff key 3 Straight edge
4 Crankshaft
sprocket
5 Inset: shims
Note that with single row type, it is important to align the sides of the teeth and not the raised hub of the sprocket
Once the nuts have been removed, the head gasket will be disturbed, and the gasket will almost certainly leak or blow after refitting. For this reason, removal of the rocker shaft assembly cannot be done without removing the cylinder head and renewing the head gasket.
Removal
2 Remove the cylinder head as described in Section 7 or 8 as applicable. 3 To dismantle the rocker shaft assembly, release the rocker shaft locating screw, remove the split pins, flat washers, and spring washers from each end of the shaft and slide from the shaft the pedestals, rocker arms, and rocker spacing springs (see illustration). Keep all the components in order and make a note of each component’s correct fitted position and orientation as it is removed, to ensure it is fitted correctly on reassembly.
Inspection
4 Check the rocker arms for wear of the rocker bushes, for wear at the rocker arm face which bears on the valve stem, and for wear of the adjusting ball-ended screws. Wear in the rocker arm bush can be checked by gripping the rocker arm tip and holding the rocker arm in place on the shaft, noting if there is any lateral rocker arm shake. If shake is present, and the arm is very loose on the shaft, remedial action must be taken. Pressed steel valve rockers cannot be renovated by renewal of the rocker arm bush. It is necessary to fit new rocker arms. Forged rocker arms which have worn bushes may be taken to a Rover dealer or engine reconditioning specialist to have the old bush drawn out and a new bush fitted. Forged rockers and pressed steel rockers are interchangeable in sets of eight, but, where one or two pressed steel rockers only require renewal, it is not advised to replace them with the forged type. 5 Check the tip of the rocker arm where it bears on the valve head for cracking or serious wear on the case hardening. If none is present re-use the rocker arm. Check the lower half of the ball on the end of the rocker arm adjusting screw. On high performance mini engines, wear on the ball and top of the
pushrod is easily noted by the unworn “pip” which fits in the small central oil hole on the ball. The larger this “pip” the more wear has taken place to both the ball and the pushrod. Check the pushrods for straightness by rolling them on the bench. Renew any that are bent.
Refitting
6 To reassemble the rocker shaft fit the split pin, flat washer and spring washer at the rear end of the shaft and then slide on the rocker arms, rocker shaft pedestals, and spacing springs in the same order in which they were removed. 7 With the front pedestal in position, screw in the rocker shaft locating screws and slip the locating plate into position. Finally, fit to the front of the shaft the spring washer, plain washer, and split pin, in that order. 8 Refit the cylinder head as described in Section 7 or 8.
7 Cylinder head (carburettor
engines) - removal and
refitting
3
Note: If working on a pre-1990 engine fitted with emission control equipment, it will be necessary to first remove the diverter valve, air pump and associated hoses before proceeding with the removal sequence. Detailed removal procedures for these components will be found in Chapter 4C.
Removal
1 Disconnect the battery negative lead. For improved working clearance, remove the bonnet as described in Chapter 11. 2 Drain the cooling system as described in Chapter 1. 3 Slacken the clips securing the radiator top hose and remove the hose. 4 On models fitted with an ignition shield over the front of the engine, release the three retaining lugs and lift off the shield. 5 Make a note of the electrical connections at the ignition coil and disconnect them. Now undo and remove the nut securing the coil bracket to the cylinder head and lift away the coil. 6 Undo and remove the nuts or bolts securing
the radiator upper support bracket to the thermostat housing and radiator. Remove the bracket. 7 Refer to Chapter 4A and remove the air cleaner assembly and carburettor(s). 8 Undo and remove the retaining nuts and bolts, and lift off the clamps securing the exhaust front pipe to the manifold. On Cooper S models, undo and remove the nuts and flat washers securing the inlet and exhaust manifolds to the cylinder head. Lift off the inlet manifold, ease the exhaust manifold back off the cylinder head studs and tie it securely in this position. 9 Slacken the water pump-to-cylinder head bypass hose retaining clips. 10 Slacken the securing clip and remove the heater hose from the heater valve on the cylinder head. Now disconnect the control cable from the valve. 11 Make a note of their positions and then remove the HT leads from the spark plugs. 12 Detach the temperature gauge electrical lead from the sender unit. 13 Undo the two rocker cover retaining bolts. Lift out the bolts along with the ignition shield brackets and lift the rocker cover and gasket away. Collect the rocker cover retaining bolt dished washers from the top of the two rubber seals. 14 Slacken the four rocker pedestal nuts and the nine main cylinder head nuts, half a turn at a time, in the reverse sequence to that shown (see illustration 7.31). On some 1275 cc engines an additional nut and bolt are located at the front and rear of the cylinder head, and these must be released first. When the tension is released from all the nuts, they may then be removed, one at a time, from their studs. 15 Recover the pedestal plate (where fitted) the lift off the rocker shaft assembly complete and place it to one side (see illustrations). 16 Lift out the pushrods, keeping them in order according to their respective valves (see illustration).
Engine in-car repair procedures 2A•7
2A
6.3 Rocker shaft components dismantled for inspection
7.15a Recover the pedestal plate (where fitted) . . .
7.15b . . . then lift off the rocker shaft assembly
The easiest way to keep the pushrods in order is to push them through a sheet of
thick paper or thin card, in the correct sequence, then number them 1 to 8.
17 The cylinder head can now be removed by lifting upwards. If the head is jammed, try to rock it to break the seal. Under no circumstances try to prise it apart from the block with a screwdriver or cold chisel, as damage may be done to the faces of the head or block. If other methods fail to work, strike the head sharply with a plastic or wooden headed hammer, or with a metal hammer with an interposed piece of wood to cushion the blows. Under no circumstances must you hit the head directly with a metal hammer, as this may cause the iron casting to fracture. Several sharp taps with the hammer, at the same time pulling upwards, should free the head. Lift the head off squarely and place it on one side. 18 If the cylinder head is to be dismantled for overhaul, refer to Part B of this Chapter. Refer to Section 6 if the rocker shaft assembly is to be dismantled.
Preparation for refitting
19 The mating faces of the cylinder head and cylinder block must be perfectly clean before refitting the head. Use a metal or hard plastic scraper to remove all traces of gasket and carbon; also clean the piston crowns. Take particular care during the cleaning operations, as the mating faces and piston crowns can be
easily scored. Also, make sure that the carbon is not allowed to enter the oil and water passages - this is particularly important for the lubrication system, as carbon could block the oil supply to the engine’s components. Using adhesive tape and paper, seal the water and oil holes in the cylinder block. To prevent carbon entering the gap between the pistons and bores, smear a little grease in the gap. After cleaning each piston, use a small brush to remove all traces of grease and carbon from the gap, then wipe away the remainder with a clean rag. Clean all the pistons in the same way. 20 Check the mating surfaces of the cylinder block and the cylinder head for nicks, deep scratches and other damage. If slight, they may be removed carefully with a file, but if excessive, machining may be the only alternative to renewal. 21 If warpage of the cylinder head gasket surface is suspected, use a straight-edge to check it for distortion. Refer to Part B of this Chapter if necessary. 22 Check the condition of the cylinder head studs and nuts, and particularly their threads. Wash the nuts in a suitable solvent and wipe clean the studs. Check each for any sign of visible wear or damage, renewing any if necessary.
Refitting
23 After checking that both the cylinder block and cylinder head mating faces are perfectly clean, generously lubricate each cylinder with engine oil. 24 Always use a new cylinder head gasket as the old gasket will be compressed and not capable of giving a good seal. It is also easier at this stage to refit the small bypass hose from the water pump to the cylinder head. 25 The cylinder head gasket is marked “FRONT” and “TOP” and should be fitted in position according to the markings (see
illustrations). 26 With the gasket in position carefully lower
the cylinder head onto the cylinder block. Make sure that the bypass hose engages with the pipe stub on the cylinder head as the head is lowered into place. 27 Fit the cylinder head nuts and washers finger tight to the five cylinder head holding­down studs, which remain outside the rocker cover. 28 Fit the pushrods in the same order in which they were removed. Ensure that they locate properly in the stems of the tappets, and lubricate the pushrod ends before fitting. 29 The rocker shaft assembly can now be lowered over its eight locating studs. Take care that the rocker arms are the right way round. Lubricate the ball ends of the tappet adjusting screws and insert them in the pushrod cups. Note: Failure to place the ball
ends in the cups can result in them seating on the edge of a pushrod or outside it when the head and rocker assembly is pulled down tight.
30 Fit the four rocker pedestal nuts and washers, and then the four cylinder head stud nuts and washers, which also serve to hold down the rocker pedestals. Pull the nuts down evenly, but without tightening them right up. 31 When all is in position, the nine cylinder head nuts and the four rocker pedestal nuts can be tightened down in the order shown (see illustration). Turn the nuts a quarter of a turn at a time and tighten to the specified torque
Note: On 1275 cc engines having an additional nut and bolt, these should be tightened last.
2A•8 Engine in-car repair procedures
7.16 Remove the pushrods, keeping them in order
7.25a The cylinder head gasket is marked FRONT . . .
7.25b . . . and TOP
7.31 Cylinder head nut tightening sequence
A and B indicate additional bolt and nut on some 1275 cc engines. Reverse this order for slackening
32 Reconnect the wire to the temperature gauge sender unit. 33 Refit the heater hose to the heater valve then tighten the heater hose and the bypass hose retaining clips. 34 Refer to Chapter 4C and reconnect the exhaust front pipe and, on Cooper S models, the inlet and exhaust manifolds.
35 Refit the radiator upper support bracket. 36 Refit the ignition coil and bracket and
reconnect the wiring.
37 Refit and secure the radiator top hose. 38 Refer to Chapter 4A and refit the
carburettor(s). 39 Refer to Section 4 and adjust the valve clearances then refit the rocker cover, HT leads and associated components. 40 Reconnect the battery then refill the cooling system as described in Chapter 1. If removed, refit the bonnet, referring to Chapter 11 if necessary.
8 Cylinder head (fuel injection
engines) - removal and
refitting
3
Note: Observe the precautions in Section 1 of Chapter 4B before working on any component in the fuel system.
Removal
1 Disconnect the battery negative lead. For
improved working clearance, remove the bonnet as described in Chapter 11. 2 Drain the cooling system as described in Chapter 1. 3 Release the fasteners and remove the ignition cover from the front of the engine. 4 Refer to Chapter 4B and remove the air cleaner assembly. 5 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). 6 Working from underneath the car, slacken and remove the single bolt securing the exhaust front pipe to its mounting bracket on the transmission. Undo the three nuts securing the front pipe to the manifold, then disconnect it and recover the gasket. 7 Trace the wiring back from the exhaust system lambda sensor (which is screwed into
the exhaust manifold), releasing it from any relevant cable-ties, and disconnect its wiring connector from the main harness.
8 Lower the car to the ground. 9 Undo the bolt and remove the retaining clip
securing the injector housing fuel pipes to the bulkhead. 10 Bearing in mind the information contained in Chapter 4B, Section 6 on depressurising the fuel system, using an open-ended spanner to retain each adapter, slacken the union nuts and disconnect the feed and return pipes from the throttle body assembly. Plug each pipe and adapter, to minimise the loss of fuel and prevent the entry of dirt into the system. 11 Release the retaining clips and disconnect the wiring connectors from the injector housing, the throttle potentiometer and the stepper motor. Free the wiring from any relevant retaining clips, and position it clear of the throttle body assembly. 12 Slacken the accelerator cable locknuts, and free the outer cable from its mounting bracket. Release the inner cable from the throttle cam, and position the cable clear of the throttle body. 13 On automatic transmission models, disconnect the governor control rod from the throttle body linkage. 14 Disconnect the two vacuum hoses from the rear of the inlet manifold, noting their correct fitted positions; note that the hoses are colour-coded for identification purposes. 15 Undo the union bolt securing the brake servo vacuum hose to the inlet manifold, and recover the hose union sealing washers. 16 Slacken the retaining clips and disconnect the coolant hoses from the left-hand side of the inlet manifold. 17 Slacken the clips securing the radiator top hose to the thermostat housing and radiator, and remove the hose. 18 Undo the radiator upper mounting bracket retaining bolts, and remove the bracket from the side of the cylinder head and radiator. 19 Release the retaining clip(s), and disconnect the two vacuum/breather hoses from the left-hand end of the cylinder head, and the single hose from the right-hand end of the head (see illustrations).
20 Undo the nut securing the ignition coil to the front of the cylinder head, then release the coil from its mounting stud and position it clear of the cylinder head (see illustration). 21 Make a note of the correct fitted positions of the HT leads, and disconnect them from the spark plugs. 22 Remove the cylinder head assembly as described in paragraphs 13 to 18 of Section 7, noting that it will be necessary to disconnect the wiring connectors from the PTC heater and coolant temperature sensor (situated on the underside of the inlet manifold) as they become accessible.
Preparation for refitting
23 Refer to Section 7, paragraphs 19 to 22.
Refitting
24 Refit the cylinder head as described in
Section 7, not forgetting to reconnect the PTC heater and coolant temperature sensor wiring connectors as the head assembly is lowered into position on the cylinder block. 25 The remainder of the refitting process is a direct reversal of the removal procedure, noting the following points:
a) Ensure that all pipes/hoses are correctly
reconnected, and (where necessary) are securely held in position by their retaining clips.
c) Tighten all nuts and bolts to the specified
torque setting (where given).
d) Position a sealing washer on either side of
the brake servo vacuum hose union, and tighten the union bolt securely.
e) Refill the cooling system as described in
Chapter 1
f) On completion, reconnect the battery,
and adjust the accelerator cable as described In Chapter 4B.
9 Crankshaft oil seals -
renewal
3
Front (timing cover) oil seal
1 Remove the timing cover as described in Section 5, paragraphs 1 to 6 and 8 to 11. 2 Thoroughly clean the timing cover with
Engine in-car repair procedures 2A•9
2A
8.19a Disconnect the two vacuum/
breather hoses from the left-hand end of
the cylinder head . . .
8.19b . . . and the single hose from the right-hand end
8.20 Remove the nut and release the ignition coil bracket
paraffin or a suitable solvent and dry thoroughly. Pay particular attention to the mating faces of the cover and the engine front plate, ensuring that all traces of old gasket are removed. 3 Drive out the old seal and tap in the new one using the old seal to spread the load. Ensure that the open side of the seal faces inward, towards the timing chain (see
illustration). 4 Refit the timing cover as described in
Section 5, paragraphs 32 to 39.
Rear (primary gear) oil seal ­manual transmission models
Note: The majority of clutch faults experienced on Mini power units are caused by oil contamination of the clutch friction linings due to the failure of the primary gear oil seal. It is therefore recommended that the seal is renewed whenever problems of this nature are encountered. Note that Rover special tools 18G1068B and 18G1043 will be required for this operation.
5 Remove the flywheel and clutch assembly as described in Chapter 6. 6 The primary gear complete with oil seal can now be withdrawn from the crankshaft and flywheel housing as described below. 7 Lift off the C-shaped thrustwasher and backing ring that retain the primary gear in position. 8 Now screw in the threaded centre bolt of special tool 18G1068B until the base of the tool abuts the oil seal. Pull the primary gear outwards as far as it will go and slide the two collets of 18G1068B between the groove at the rear of the primary gear splines and the base of the tool body. 9 Now slowly unscrew the threaded centre bolt of the tool while holding the tool body. This will cause the primary gear to be withdrawn from the flywheel housing, bringing the oil seal with it. 10 When the primary gear and oil seal are clear of the housing, lift them off the end of the crankshaft, remove the tool and slide the oil seal off the primary gear. 11 To fit a new oil seal first slide the primary gear onto the crankshaft and secure with the C-shaped washer and backing ring. 12 To avoid damage to the oil seal as it is fitted, place the protective sleeve, special tool 18G1043, over the primary gear, or if this tool is not available cover the primary gear splines and the stepped shoulder with masking tape. 13 Lubricate the lip of the oil seal, and very carefully slide it over the primary gear and into position against the flywheel housing. The open part of the seal must be facing towards the engine. 14 Screw on the threaded centre bolt of special tool 18G1068B and, when the body of the tool contacts the seal, fully tighten the centre bolt, thus forcing the seal squarely into the housing. Remove the tool when the face of the seal is flush with the housing. 15 The flywheel and clutch assembly can now be refitted as described in Chapter 6.
Rear (torque converter output gear) oil seal - automatic transmission models
Note: Rover special tools 18G1068B and 18G1098 should ideally be obtained for this operation.
16 Remove the torque converter as described in Section 11. 17 Note the fitted depth of the oil seal in the converter housing so that the new seal may be fitted in the same position. 18 Using a hooked instrument, or alternatively Rover special tool 18G1087, extract the oil seal from the converter housing. 19 To protect the lips of the new seal as it is fitted, wrap adhesive tape around the converter output gear splines or preferably use Rover special tool 18G1098. 20 Using a suitable length of tubing or preferably Rover special tool 18G1068B, install the oil seal into the housing to the same position as noted during removal. Note that if the seal is not positioned correctly it may cover an important oil drain hole in the housing. 21 The torque converter can now be refitted as described in Section 11.
10 Flywheel (manual
transmission models) -
removal and refitting
3
The flywheel on all manual transmission models is removed complete with the clutch assembly, the components then being separated after removal. Full details of clutch and flywheel removal and refitting are contained in Chapter 6.
11 Torque converter (automatic
transmission models) -
removal and refitting
3
Removal
Note: Rover special tool special tool 18G1086 will be required to release the torque converter from the crankshaft.
1 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”).
2 Disconnect the battery negative lead. If greater working clearance is required, remove the bonnet as described in Chapter 11. 3 Remove the front grille as described in Chapter 11. 4 Detach the heater air duct from the air inlet under the right-hand front wing. Remove the air inlet from the inner wing panel. 5 Remove the starter motor as described in Chapter 5A. 6 On fuel injection models carry out the following:
a) Remove the air cleaner assembly, the
engine management ECU and the crankshaft sensor as described in Chapter 4B.
b) Disconnect the oil separator breather
hose from the right-hand end of the cylinder head, then undo the two bolts securing the separator to the torque converter housing. Remove the separator and hose assembly from the engine, along with its gasket.
c) Slacken and remove the screw, situated
just to the right of the brake servo unit, securing the earth leads to the bulkhead.
d) Undo the bolts securing the wiring
harness retaining clip and starter motor lead brackets to the converter housing, then position the wiring clear of the engine.
7 On early models, undo and remove the screws securing the starter solenoid to the inner wing panel. Lift off the solenoid and position it out of the way. 8 If the ignition coil is mounted on the flywheel housing, or on a bracket secured to one of the cylinder head studs, remove the coil and mounting bracket and position it well clear. 9 On later Mini 850 and 1000 models, remove the horn and place it to one side. 10 Undo and remove the two bolts securing the engine tie-bar and bracket to the side of the cylinder block. Note that on later models one of the bolts also retains the engine earth strap. 11 Undo and remove the nuts and/or bolts securing the radiator upper support bracket to the radiator and thermostat housing. Withdraw the bracket. Note: It is not
necessary to remove the support bracket if a large clearance exists between the radiator and left-hand inner wing panel, as is the case on later Mini 850 and 1000 models.
12 Place a jack beneath the torque converter housing end of the transmission casing and just take the weight of the power unit. Use a block of wood interposed between the casing and the jack to spread the load. 13 From beneath the car undo and remove the two nuts and bolts securing the right-hand engine mounting to the subframe side members. The best way to do this is to engage the help of an assistant to hold the bolts from above while the nuts are undone from below. The bolt heads are tucked away beneath the converter housing and can only be reached with a small open-ended spanner.
2A•10 Engine in-car repair procedures
9.3 Timing cover oil seal must be fitted with the open side towards the chain
14 Having released the mounting, jack up the
power unit sufficiently to enable the nine bolts securing the converter housing cover to be removed. Note that on early models one of the front bolts also retains the engine earth strap. On all models the rear bolts are quite inaccessible, requiring a good deal of patience and a short spanner. 15 When all the bolts are undone, lift off the converter housing cover. 16 Knock back the locktabs, and undo and remove three equally spaced bolts from the centre of the converter. Leave the other three bolts in position. 17 Knock back the lockwasher securing the large converter centre retaining bolt. Using a large socket and bar, undo and remove the torque converter centre bolt and withdraw the driving collar. Use a screwdriver inserted through the hole in the top of the converter housing and engaged with the ring gear teeth to prevent the torque converter from turning. 18 Rotate the crankshaft until the timing marks on the converter periphery are at approximately the 3 o’clock position. 19 The torque converter is a taper fit on the end of the crankshaft and it will be necessary to obtain Rover special tool 18G1086 to remove it. The tool is bolted to the torque converter through the holes of the three previously removed converter retaining bolts. With the adapter in position on the end of the crankshaft, tighten the tool centre bolt until the torque converter breaks free of the taper, and then lift it off the crankshaft.
Refitting
20 Set the engine with No 1 piston at TDC on compression as described in Section 3. 21 Before fitting the torque converter, it will be first necessary to refit the three central bolts removed to allow the special converter removal tool to be used during dismantling. Then remove each pair of bolts in turn from the converter centre and fit new locking plates. Tighten the six bolts to the specified torque wrench setting and bend over the lock tabs. On
no account remove all six bolts at any one time.
22 Slide the torque converter onto the end of the crankshaft, with the timing marks uppermost. Refit the driving collar, a new lockwasher and the retaining bolt. Tighten the retaining bolt to the specified torque then knock back the lockwasher. 23 The remainder of refitting is the reverse sequence to removal.
12 Engine/transmission
mountings - renewal
3
General information
1 The engine/transmission is supported on two rubber mountings which are in turn bolted to the sides of the front subframe. One mounting is located under the radiator (left-
hand mounting), and the other at the base of the flywheel or torque converter housing cover, to which it is attached (right-hand mounting). Fore-and-aft movement of the power unit is controlled by a tie-bar, one end of which is attached to the engine, and the other to a bracket on the bulkhead. Rubber bushes are used at each end to absorb vibration. On later models an additional lower tie-bar is used, one end of which is bolted to the subframe and the other to a bracket on the transmission. A point worth noting is that the engine tie-bar rubber bushes are prone to wear and this is usually noticed as severe judder as the clutch is engaged on manual transmission models, or excessive movement of the complete power unit when accelerating and decelerating.
Right-hand mounting renewal
2 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). 3 Disconnect the battery negative lead. If greater working clearance is required, remove the bonnet as described in Chapter 11. 4 Remove the front grille, referring to Chap­ter 11 if necessary. 5 Detach the heater air duct from the air inlet under the right-hand front wing. Remove the air inlet from the inner wing panel. 6 Remove the starter motor as described in Chapter 5A. 7 On fuel injection models carry out the following:
a) Remove the air cleaner assembly, the
engine management ECU and the crankshaft sensor as described in Chapter 4B.
b) Disconnect the oil separator breather
hose from the right-hand end of the cylinder head, then undo the two bolts securing the separator to the flywheel/torque converter housing. Remove the separator and hose assembly from the engine, along with its gasket.
c) Slacken and remove the screw, situated
just to the right of the brake servo unit, securing the earth leads to the bulkhead.
d) Undo the bolts securing the wiring
harness retaining clip and starter motor lead brackets to the flywheel/converter housing, then position the wiring clear of the engine.
8 On early models, undo and remove the screws securing the starter solenoid to the inner wing panel. Lift off the solenoid and position it out of the way. 9 If the ignition coil is mounted on the flywheel/converter housing, or on a bracket secured to one of the cylinder head studs, remove the coil and mounting bracket and position it well clear. 10 On manual transmission models, detach the clutch slave cylinder mounting plate from the flywheel housing, taking care to retain the spacer. Withdraw the cylinder from the pushrod and place the cylinder and mounting plate to one side. 11 On later Mini 850 and 1000 models, remove the horn and place it to one side. 12 Undo and remove the two bolts securing the engine tie-bar and bracket to the side of the cylinder block. Note that on later models one of the bolts also retains the engine earth strap. 13 Undo and remove the nuts and/or bolts securing the radiator upper support bracket to the radiator and thermostat housing. Withdraw the bracket. Note: It is not
necessary to remove the support bracket if a large clearance exists between the radiator and left-hand inner wing panel, as is the case on later Mini 850 and 1000 models.
14 Place a jack beneath the flywheel/torque converter housing end of the transmission casing and just take the weight of the power unit. Use a block of wood interposed between the casing and the jack to spread the load. 15 From beneath the car undo and remove the two nuts and bolts securing the right-hand engine mounting to the subframe side members (see illustration). The best way to do this is to engage the help of an assistant to hold the bolts from above while the nuts are undone from below. The bolt heads are tucked away and can only be reached with a small open-ended spanner. 16 Having released the mounting, jack up the power unit sufficiently to enable the nine bolts securing the flywheel/converter housing cover to be removed. Note that on early models one of the front bolts also retains the engine earth strap. On all models the rear bolts are quite inaccessible, requiring a good deal of patience and a short spanner. 17 When all the bolts are undone, lift off the flywheel/converter housing cover. 18 With the cover removed, undo the bolts securing the engine mounting and lift off the mounting. 19 Refitting is the reverse sequence to removal.
Left-hand mounting renewal
20 Remove the radiator as described in Chapter 3. 21 Position a jack beneath the left-hand side of the transmission casing, and, using a block of wood to spread the load, just take the weight of the power unit.
Engine in-car repair procedures 2A•11
2A
12.15 Right-hand engine mounting-to-
subframe retaining nuts
22 Undo and remove the two nuts, bolt and
spring washers securing the mounting to the subframe. 23 Raise the jack slightly and remove the bolts securing the mounting to the bracket on the transmission casing. The engine mounting can now be withdrawn. 24 Refitting is the reverse sequence to removal.
Upper tie-bar and bushes renewal
25 Undo and remove the two bolts securing the tie-bar and mounting bracket to the right­hand side of the engine (see illustration). Move the tie-bar sideways and recover any spacing washers that may be fitted. 26 If the tie-bar is secured to its mounting bracket on the bulkhead by a through-bolt and locknut, remove the locknut and bolt and lift away the tie-bar. 27 If the tie-bar is secured by a stud with nuts and spring washers at each end, undo
and remove the nuts and spring washers, then slacken the four nuts securing the clutch and brake master cylinder to the bulkhead. When sufficient clearance exists, lift up the tie-bar upper mounting bracket over the tie-bar stud, and withdraw the tie-bar. 28 With the tie-bar removed, slide out the rubber bushes and spacers and, if there is any sign of swelling or deterioration of the rubber whatsoever, renew the bushes. 29 Refitting is the reverse sequence to removal.
Lower tie-bar and bushes renewal
30 The lower tie-bar fitted to later models may be mounted in one of two positions; either bolted to a bracket on the left-hand side of the transmission at one end and to the rear of the subframe at the other, or bolted to a bracket on the right-hand side of the transmission at one end and to the front of the
subframe at the other. The renewal procedure is the same for both types (see illustration). 31 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). 32 Undo and remove the bolts securing the tie-bar to the transmission bracket and subframe, and withdraw the tie-bar. 33 To remove the bushes it will be necessary to draw them out using a tube of suitable diameter, a long bolt and nut, and packing washers. The new bushes are refitted in the same way but lubricate them with liquid detergent before fitting. 34 Refitting is the reverse sequence to removal.
13 Distributor driveshaft -
removal and refitting
1
Removal
1 Set the engine with No 1 cylinder at TDC on compression as described in Section 3. 2 Remove the distributor as described in Chapter 5B. 3 Where a distributor base housing is fitted to the cylinder block, unscrew the single retaining bolt and lockwasher and remove the housing. 4 Look down into the distributor aperture and observe the position of the slot in the distributor driveshaft. With No 1 piston at TDC, the slot should be positioned as shown according to engine type (carburettor engines or fuel injection engines) (see illustrations).
2A•12 Engine in-car repair procedures
12.30 Lower engine tie-bar attachments12.25 Removing the engine upper tie-bar
from the cylinder block
13.4a Distributor driveshaft components and fitting details ­carburettor engines
Inset A shows the position of the slot ready for fitting Inset B shows the shaft correctly installed
1 Driveshaft 2 Housing 3 Retaining screw
45⁄16 in UNF bolt (for removal
and refitting of driveshaft)
13.4b Distributor driveshaft fitting details - fuel-injection models
A Drive slot position prior to engagement with skew gear B Correct drive slot position with shaft correctly installed
There is a degree of conflicting information from the manufacturer as to the correct position of this slot on later engines. As a general rule, when refitting the driveshaft, set the slot in the same position it was in prior to removal. If there is any doubt about the original position, set it as shown in the illustrations when refitting. 5 Screw into the end of the distributor driveshaft a 5⁄16 in UNF bolt. A tappet cover bolt (where fitted) is ideal for this purpose. The driveshaft can then be lifted out, the shaft being turned slightly in the process to free the shaft skew gear from the camshaft skew gear (see illustration).
Refitting
6 With the engine still positioned with No1 piston at TDC, hold the driveshaft so that its slot is in the correct position for refitting as shown in the accompanying illustrations, ie so that its larger segment is uppermost (offset slot towards the bottom). Engage the driveshaft gear with the camshaft skew gear, and push the drive fully into position. As the gear engages, the driveshaft will rotate anti­clockwise to the final, correct fitted position. If necessary, withdraw the driveshaft again and adjust its position as necessary until this is so.
7 Remove the bolt from the driveshaft.
8 Where applicable, refit the distributor base
housing using a new O-ring and lock it in position with the single bolt and lockwasher. 9 The distributor can now be refitted as described in Chapter 5B.
14 Oil pressure relief valve -
removal, inspection and refitting
1
Removal
1 To prevent excessive oil pressure - for example when the engine is cold - an oil pressure relief valve is built into the right-hand side of the engine just below the oil delivery pipe union. 2 The relief valve is identified externally by a large domed hexagon nut. To remove the unit unscrew the nut and remove it, complete with the two fibre or copper sealing washers. The relief spring and the relief spring cup can then be easily extracted (see illustration).
Inspection
3 In position, the metal cup fits over the opposite end of the relief valve spring resting in the dome of the hexagon nut, and bears against a machining in the block. When the oil
pressure exceeds the specified pressure the cup is forced off its seat and the oil returns, via a drilling, directly to the sump. 4 Check the tension of the spring by measuring its free length. If it is shorter than the length shown in the Specifications it should be renewed. Check the condition of the cup checking carefully for wear ridges which would prevent the cup seating effectively. Renew the cup if its condition is suspect.
Refitting
5 Refitting is the reverse sequence to removal.
15 Oil filter housing and delivery
pipe - removal and refitting
1
Removal
1 Drain the engine/transmission oil and remove the oil filter as described in Chapter 1. 2 On manual transmission models, Unscrew the banjo union bolt securing the delivery pipe to the cylinder block. Note that on later 1275 cc engines a tube nut and olive type fitting is used instead of the banjo union. At the other end of the pipe unscrew the nut securing the pipe to the oil filter housing (see illustrations). Lift away the pipe and collect the two copper washers at the banjo union, or the rubber seals at the tube nut connections, according to type. be prepared for oil spillage. 3 On manual transmission models, unscrew the two nuts and slide the oil filter housing off the cylinder block studs. Recover the gasket. 4 On automatic transmission models, undo the two bolts and remove the filter housing from the top of the transmission casing flange. Recover the gasket. 5 Thoroughly clean the components and remove all traces of gasket from the mating surfaces.
Engine in-car repair procedures 2A•13
2A
15.2a Oil feed pipe banjo union at the engine . . .
15.2b . . . and pipe nut attachment at the filter housing
13.5 Using a 5⁄16 in UNF bolt to remove the distributor driveshaft 14.2 Removing the oil pressure relief valve
6 If oil leakage from the pipe unions on later
1275 cc (12A) engines has been experienced, a modified pipe and tube nut assembly is available. Consult a Rover dealer for further information on this modification.
Refitting
7 Refitting is the reverse sequence to removal, bearing in mind the following points:
a) Use a new filter housing gasket and new
copper washers at the banjo union.
b) When refitting the delivery pipe with banjo
union fitting, engage the threads of the union nut at the filter housing first, then fit the banjo union with a copper washer on each side of the union head. Tighten the fittings securely.
16 Oil cooler - removal and
refitting
1
Removal
1 Disconnect the battery negative lead. 2 Remove the front grille as described in
Chapter 11. 3 Place a suitable container below the oil cooler. On Cooper S models, unscrew the two hose unions from the top of the oil cooler and move the hoses clear. On 1990-on 1275 cc engines, unscrew the banjo union bolt on the top of the oil cooler and recover the two
sealing washers. On all models, cover the disconnected unions with tape to prevent entry of dust and dirt. 4 Unscrew the mounting bolts and withdraw the oil cooler. On 1990-on 1275 cc engines, unscrew the lower banjo union bolt when sufficient clearance exists and recover the two sealing washers.
Refitting
5 Refitting is a reversal of removal, but top-up the engine oil level as necessary (see “Weekly Checks”).
2A•14 Engine in-car repair procedures
2B
Chapter 2 Part B:
Engine removal and overhaul procedures
Engine general
Engine codes:
85H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 848 cc engines
99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 998 cc engines
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1098 cc engines
12H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1275 cc engines
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1275 cc engines
Valves
Valve head diameter:
Inlet:
85H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.76 to 27.89 mm
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.23 to 29.36 mm
12H:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.20 to 33.32 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.58 to 35.71 mm
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35.58 to 35.71 mm
Exhaust:
85H, 99H and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.40 to 25.53 mm
12H:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.24 to 29.37 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30.83 to 30.96 mm
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.25 to 29.38 mm
Valve stem diameter:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.094 to 7.107 mm
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.082 to 7.094 mm
Valve stem-to-guide clearance:
Inlet:
85H, 99H and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.038 to 0.064 mm
12H and 12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.080 mm
Exhaust:
85H, 99H and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.051 to 0.076 mm
12H and 12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.080 mm
Valve seat angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45º
Camshaft and tappets - removal, inspection and refitting . . . . . . . . 9
Crankshaft - refitting and running clearance check . . . . . . . . . . . . . 17
Crankshaft - removal and inspection . . . . . . . . . . . . . . . . . . . . . . . . . 12
Cylinder block/crankcase - cleaning and inspection . . . . . . . . . . . . . 13
Cylinder head - dismantling, cleaning, inspection and reassembly . 8
Engine - initial start-up after overhaul and reassembly . . . . . . . . . . . 19
Engine and automatic transmission - separation and reconnection . 6 Engine and manual transmission - separation and reconnection . . . 5
Engine overhaul - preliminary information . . . . . . . . . . . . . . . . . . . . . 7
Engine overhaul - reassembly sequence . . . . . . . . . . . . . . . . . . . . . . 15
Engine/transmission - removal and refitting . . . . . . . . . . . . . . . . . . . 3
Engine/transmission removal - preparation and precautions . . . . . . 2
Engine/transmission (with front subframe) - removal and refitting . . 4
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Main and big-end bearings - inspection and selection . . . . . . . . . . . 14
Oil pump - removal, inspection and refitting . . . . . . . . . . . . . . . . . . .10
Piston/connecting rod assemblies - refitting and big-end bearing
clearance check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Piston/connecting rod assemblies - removal, inspection, separation
and reconnection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Piston rings - refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2B•1
Specifications
Contents
Easy, suitable for
novice with little experience
Fairly easy, suitable for beginner with some experience
Fairly difficult,
suitable for competent DIY mechanic
Difficult, suitable for experienced DIY mechanic
Very difficult,
suitable for expert DIY or professional
Degrees of difficulty
5
4
3
2
1
Valve springs
Valve spring free length:
85H and 99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.45 mm
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49.70 mm
12H:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49.70 mm
Cooper S Mk III outer spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.19 mm
Cooper S Mk III Inner spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.31 mm
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49.53 mm
Camshaft and camshaft bearings
Camshaft journal diameter:
Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.304 to 42.316 mm
Centre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.218 to 41.231 mm
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34.857 to 34.887 mm
Bearing inside diameter (reamed after fitting):
85H:
Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.342 to 42.355 mm
Centre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.262 to 41.288 mm
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34.908 to 34.938 mm
99H and 10H:
Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.342 to 42.355 mm
Centre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.225 to 41.267 mm
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34.912 to 34.925 mm
12H and 12A:
Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.342 to 42.355 mm
Centre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.262 to 41.288 mm
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34.908 to 34.938 mm
Bearing running clearance:
85H:
Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.012 to 0.051 mm
Centre and rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.031 to 0.069 mm
All other engines:
Front, centre and rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 to 0.051 mm
Camshaft endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.076 to 0.178 mm
Cylinder block
Bore diameter:
85H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.94 mm
99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.59 mm
10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.59 mm
12H and 12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70.61 mm
Maximum cylinder bore oversize (after reboring):
85H and 99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +1.02 mm
All other engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.51 mm
Maximum cylinder bore/liner taper* . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.10 mm
Maximum cylinder bore/liner ovality* . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.10 mm
*These are suggested figures, typical for this type of engine - no exact values are stated by Rover.
Pistons
Piston-to-bore clearance:
85H:
Top of skirt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.066 to 0.81 mm
Bottom of skirt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.015 to 0.030 mm
99H and 10H:
Top of skirt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.060 to 0.085 mm
Bottom of skirt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.010 to 0.026 mm
12H:
Top of skirt:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.070 to 0.114 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.063 to 0.072 mm
Bottom of skirt:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.031 to 0.056 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.048 to 0.063 mm
12A:
Top of skirt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.074 to 0.114 mm
Bottom of skirt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.023 to 0.064 mm
Piston oversizes available:
85H and 99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.254 mm, +0.508 mm, +0.762 mm, +1.02 mm
All other engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.254 mm, +0.508 mm,
2B•2 Engine removal and overhaul procedures
Piston rings
Piston ring end gap:
85H and 99H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.178 to 0.305 mm
10H:
Compression rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.178 to 0.305 mm
Oil control ring:
Rails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.305 to 0.711 mm
Side springs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.54 to 3.81 mm
12H:
Top compression ring:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.28 to 0.41 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20 to 0.33 mm
2nd and 3rd compression rings . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20 to 0.33 mm
Oil control ring:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.254 to 1.02 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20 to 0.33 mm
12A:
Top compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 to 0.45 mm
Second compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20 to 0.33 mm
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.38 to 1.04 mm
Ring-to-groove clearance (compression rings) . . . . . . . . . . . . . . . . . . . 0.038 to 0.089 mm
Crankshaft
Main bearing journal diameter:
85H, 99H* and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.46 to 44.47 mm
12H:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.83 to 50.84 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.81 to 50.82 mm
12A:
No colour code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.83 to 50.84 mm
Red colour code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.81 to 50.82 mm
Green colour code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.82 to 50.83 mm
Yellow colour code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.83 to 50.84 mm
Minimum main bearing journal regrind diameter:
85H, 99H* and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.45 mm
12H:
1275 GT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49.78 mm
Cooper S Mk III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.30 mm
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50.32 mm
Main bearing running clearance:
85H, 99H* and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 to 0.068 mm
12H and 12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.017 to 0.058 mm
Big-end bearing journal diameter:
85H, 99H* and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.28 to 41.29 mm
12H and 12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.44 to 44.46 mm
Minimum big-end journal regrind diameter:
85H, 99H* and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40.27 mm
12H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.44 mm
12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.93 mm
Big-end bearing running clearance:
85H, 99H* and 10H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.025 to 0.063 mm
12H and 12A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.038 to 0.081 mm
Crankshaft endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.051 to 0.076 mm
*Refer to a Rover dealer for information on later models
Lubrication system
Oil pump shaft and rotor endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.127 mm
Oil pump rotor lobe clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.152 mm
Oil pump rotor-to-body clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.254 mm
Oil pump relief pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 bars
Oil pressure:
Running . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 bars
Idling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 bar
Pressure relief valve spring:
Free length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.63 mm
Fitted length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.77 mm
Engine removal and overhaul procedures 2B•3
2B
Torque wrench settings Nm lbf ft
Connecting rod big-end:
Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 37
Nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 33
Flywheel centre bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 112
Flywheel housing nuts and bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Transmission casing to engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
Converter centre bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 112
Converter (six central bolts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 21
Converter housing nuts and bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 18
Gudgeon pin clamp bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 24
Main bearing bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 63
Timing cover and front plate:
1
4 in UNF bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5
5
16 in UNF bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 12
Oil pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8
Oil filter housing nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 14
Oil pipe banjo union . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 38
Oil pressure relief valve nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 43
Tappet side covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 3.5
2B•4 Engine removal and overhaul procedures
1 General information
Included in this Part of Chapter 2 are details of removing the engine/transmission from the car and general overhaul procedures for the cylinder head, cylinder block and all other engine internal components.
The information given ranges from advice concerning preparation for an overhaul and the purchase of replacement parts, to detailed step-by-step procedures covering removal, inspection, renovation and refitting of engine internal components.
After Section 7, all instructions are based on the assumption that the engine has been removed from the car. For information concerning engine in-car repair, as well as the removal and refitting of those external components necessary for full overhaul, refer to Part A of this Chapter and to Section 7. Ignore any preliminary dismantling operations described in Part A that are no longer relevant once the engine has been removed from the car.
2 Engine/transmission
removal - preparation and
precautions
If you have decided that an engine must be removed for overhaul or major repair work, several preliminary steps should be taken.
Locating a suitable place to work is extremely important. Adequate work space, along with storage space for the car, will be needed. If a workshop or garage is not available, at the very least, a flat, level, clean work surface is required.
If possible, clear some shelving close to the work area and use it to store the engine components and ancillaries as they are removed and dismantled. In this manner the
components stand a better chance of staying clean and undamaged during the overhaul. Laying out components in groups together with their fixing bolts, screws etc will save time and avoid confusion when the engine is refitted.
Clean the engine compartment and engine/transmission before beginning the removal procedure; this will help visibility and help to keep tools clean.
The help of an assistant should be available; there are certain instances when one person cannot safely perform all of the operations required to remove the engine from the vehicle. Safety is of primary importance, considering the potential hazards involved in this kind of operation. A second person should always be in attendance to offer help in an emergency. If this is the first time you have removed an engine, advice and aid from someone more experienced would also be beneficial.
Plan the operation ahead of time. Before starting work, obtain (or arrange for the hire of) all of the tools and equipment you will need. Access to the following items will allow the task of removing and refitting the engine/transmission to be completed safely and with relative ease: an engine hoist - rated in excess of the combined weight of the engine/transmission, a heavy-duty trolley jack, complete sets of spanners and sockets as described at the rear this manual, wooden blocks, and plenty of rags and cleaning solvent for mopping up spilled oil, coolant and fuel. A selection of different sized plastic storage bins will also prove useful for keeping dismantled components grouped together. If any of the equipment must be hired, make sure that you arrange for it in advance, and perform all of the operations possible without it beforehand; this may save you time and money.
Plan on the vehicle being out of use for quite a while, especially if you intend to carry out an engine overhaul. Read through the
whole of this Section and work out a strategy based on your own experience and the tools, time and workspace available to you. Some of the overhaul processes may have to be carried out by a Rover dealer or an engineering works - these establishments often have busy schedules, so it would be prudent to consult them before removing or dismantling the engine, to get an idea of the amount of time required to carry out the work.
When removing the engine from the vehicle, be methodical about the disconnection of external components. Labelling cables and hoses as they removed will greatly assist the refitting process.
Always be extremely careful when lifting the engine/transmission assembly from the engine bay. Serious injury can result from careless actions. If help is required, it is better to wait until it is available rather than risk personal injury and/or damage to components by continuing alone. By planning ahead and taking your time, a job of this nature, although major, can be accomplished successfully and without incident.
There are two methods of engine removal. The engine can be removed from under the car, complete with subframe, or the engine can be lifted out through the bonnet aperture. In either instance the engine is removed complete with the transmission, and also the radiator.
It is easier to lift the engine/transmission assembly out of the engine compartment with the aid of a suitable hoist than to separate the subframe from the body, and lift the body up, using the rear wheels as a pivot. This is especially so with Hydrolastic models. The subframe comprises the frame itself, the wheels, brakes, driveshafts, hubs, and suspension, complete except for shock absorbers.
In either case, it is necessary to raise and support the front of the car so that it can be worked on from underneath.
3 Engine/transmission -
removal and refitting
3
Removal
1 Disconnect the battery negative lead. 2 Drain the cooling system and the
engine/transmission oil as described in Chapter 1. 3 Remove the bonnet and front grille as described in Chapter 11. 4 On models equipped with an ignition shield mounted on the front of the engine, release the three retaining lugs and lift off the shield. 5 On carburettor engines, refer to Chapter 4A and remove the air cleaner assembly and carburettor(s). On fuel injection engines, slacken the accelerator cable locknuts, and free the outer cable from its mounting bracket. Release the inner cable from the throttle cam, and position the cable clear of the throttle body. 6 On fuel injection engines, remove the engine management ECU as described in Chapter 4B. 7 Remove the starter motor and alternator as described in Chapter 5A. 8 Where applicable, undo and remove the screws securing the starter solenoid to the inner wing panel and position the solenoid clear of the engine. 9 On models equipped with a mechanical fuel pump, disconnect the fuel inlet hose and plug it with a suitable bolt or metal rod to prevent loss of fuel. 10 On fuel injection engines, undo the bolt and remove the retaining clip securing the injector housing fuel pipes to the bulkhead. Bearing in mind the information contained in Chapter 4B, Section 6, concerning depressurisation of the fuel system, using an open-ended spanner to retain each adapter, slacken the union nuts and disconnect the feed and return pipes from the throttle body assembly. Plug each pipe and adapter, to minimise the loss of fuel and prevent the entry of dirt into the system. 11 Where applicable, disconnect the cooling system hose from the expansion tank, which is located by the side of the radiator. Undo the retaining bolt and remove the expansion tank from the engine compartment. 12 On carburettor engines, slacken the retaining clips and remove the two heater hoses. Also slacken the two securing screws and withdraw the heater control cable from the valve on the cylinder head (where applicable). On fuel injection engines, Undo the heater control coolant valve mounting bolt, then slacken the retaining clips and disconnect the coolant valve hoses from the manifold and thermostat housing. Slacken the clip and disconnect the heater unit hose from its union with the bottom radiator hose (situated directly below the coolant valve). 13 If a fresh air heater/demister blower motor
is mounted in the engine compartment, remove this unit as described in Chapter 3. 14 Undo and remove the two nuts and bolts on the clamp, or the three flange nuts securing the exhaust front pipe to the manifold. Separate the front pipe from the manifold. Note: On Cooper S models it will be
necessary to remove the complete exhaust system as described in Chapter 4C.
15 If the horn is mounted on the front body panel, disconnect the electrical leads, undo and remove the mounting bolts and withdraw the horn. 16 From beneath the right-hand front wing detach the heater fresh air ducting from the air inlet. Now withdraw the air inlet from the inner wing panel. 17 Disconnect the wiring from the following locations, after identifying the leads or wiring plugs for subsequent reconnection:
a) Leads to the temperature gauge
transmitter and oil pressure switch (where
fitted). b) LT leads at the ignition coil. c) HT leads from the spark plugs and
ignition coil, and the crankshaft sensor
wiring connector on fuel injection
engines. d) On fuel injection engines, disconnect the
wiring connectors from the injector
housing, the throttle potentiometer and
the stepper motor. Free the wiring from
any relevant retaining clips, and position it
clear of the throttle body assembly. Trace
the wiring back from the exhaust system
lambda sensor (which is screwed into the
exhaust manifold), releasing it from any
relevant cable-ties, and disconnect its
wiring connector from the main harness. e) Wiring connectors from the auxiliary
cooling fan switch (where fitted), which is
situated at the front bottom corner of the
radiator.
18 Spring back the distributor cap retaining clips, or undo the two screws and remove the cap and leads. Remove the rotor arm from the distributor shaft. 19 On manual transmission models, release the clutch slave cylinder return spring from the clutch operating lever. Undo and remove the two securing bolts and lift the slave cylinder off the flywheel housing. Tie the cylinder out of the way from a convenient place on the engine bulkhead. 20 If an oil pressure gauge is fitted, slacken the clamp screw and pull the rubber hose off the feed pipe at the rear of the engine. 21 On fuel injection engines, release the retaining clip and disconnect the vacuum hose from the pipe situated just behind the thermostat housing. Disconnect the two vacuum hoses from the rear of the inlet manifold, noting their correct fitted positions; note that the hoses are colour-coded for identification purposes. 22 On later models, disconnect the oil separator breather hose from the right-hand end of the cylinder head. Undo the two bolts
securing the separator to the flywheel housing, and remove the separator and hose assembly from the engine, along with its gasket. 23 Undo and remove the bolt securing the engine tie-bar to the side of the cylinder block. Slacken the tie-bar bulkhead mounting and move the bar back out of the way. Note that on later models the tie-bar retaining bolt also retains the engine earth strap. 24 Where fitted, remove the oil cooler as described in Part A of this Chapter. 25 On models fitted with a vacuum servo unit mounted in the engine compartment, refer to Chapter 9 and remove the servo and brake master cylinder. Unscrew the two union nuts securing the master cylinder brake pipes to the pressure-reducing valve, and remove both the pipes, noting their correct fitted positions. Plug the pressure reducing valve ports, to minimise fluid loss and prevent the entry of dirt into the system. 26 Working under the front wheel arch undo and remove the screw securing the upper suspension arm rebound rubber to the subframe and withdraw the rubber. Place a solid wooden wedge of approximately the same thickness in its place. Repeat this procedure on the other side of the car. 27 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). Remove the front roadwheels. 28 On manual transmission models fitted with a direct engagement gear lever, undo and remove the retaining screws and lift off the interior rubber boot retaining plate. Now slide the rubber boot up the gear lever slightly. From under the car, undo and remove the two bolts securing the gear lever retaining plate to the rear of the differential housing. Withdraw the gear lever into the car and lift out the anti­rattle spring and plunger from the gear lever housing. 29 On manual transmission models fitted with the early type remote control extension housing, undo and remove the four shouldered bolts securing the housing to the mounting on the rear of the differential assembly. Pull the front of the extension housing downwards to disengage the linkage and then support the front of the housing on a block of wood. 30 On manual transmission models fitted with the later rod-change type remote control extension housing, drift out the roll pin securing the collar of the remote control extension rod to the selector shaft. Undo and remove the bolt securing the fork of the steady rod to the differential housing. Release the extension rod and the steady rod from the rear of the transmission. 31 On automatic transmission models, disconnect the gear selector cable from the transmission as described in Chapter 7B, Section 6. 32 On early models undo and remove the bolt securing the engine earth strap to the flywheel/torque converter housing.
Engine removal and overhaul procedures 2B•5
2B
33 Undo and remove the nut securing the steering tie-rod balljoint to the steering arm on each side of the car. Release the balljoint tapers using a universal separator. 34 Undo and remove the nut securing the front suspension swivel hub balljoint to the upper suspension arm on each side of the car. Release the balljoint shanks from the upper suspension arms using universal balljoint separator. Move the top of the two swivel hubs outwards and allow them to hang in this position. Take care not to strain the flexible brake hoses excessively. 35 On early models equipped with rubber couplings at the inner end of each driveshaft, undo and remove the two U-bolt locknuts securing each coupling to the differential driving flanges. Withdraw the two U-bolts from each side and move the driveshafts away from the differential. 36 On later models equipped with offset sphere joints at the inner end of each driveshaft, release the joints from the differential using Rover special tool 18G1240. If this tool cannot be obtained, it is possible to withdraw the joints using a tyre lever or similar tool pivoting against the end cover retaining bolt directly below the joint. Once the joints have been released, move the driveshafts away from the differential as far as possible. 37 On Cooper S and certain automatic transmission models, undo and remove the four nuts securing each universal joint flange to the differential driving flanges. Move the driveshafts away from the differential to separate the flanges. 38 On all models undo and remove the nut and bolt securing the exhaust pipe strap to the bracket on the side of the differential housing. 39 Undo and remove the nut and bolt securing the lower engine tie-bar to the bracket on the transmission casing. Slacken the nut and bolt securing the other end and remove the tie-bar clear of the transmission.
40 Position a crane or hoist over the engine and attach chains or ropes either to brackets bolted to the cylinder head or around each end of the transmission casing. 41 With the lifting gear in position, raise it slightly and just take the weight of the engine. 42 Undo and remove the two nuts and bolts securing the two engine mountings to the side of the front subframe. 43 Make a final check that all cables, pipes and hoses have been disconnected and that all removed parts are clear of the engine. 44 The engine/transmission can now be lifted out. Tilt it backwards as it is lifted out to allow the differential to clear the rear of the subframe. When the unit is halfway out or when sufficient clearance exists, unscrew the speedometer cable knurled retaining nut and lift the cable off the housing (see illustrations). On fuel injection engines, disconnect the wiring connectors from the PTC heater and coolant temperature sensor situated on the underside of the inlet manifold. Release the wiring harness from any relevant retaining clips. 45 Now completely remove the power unit from the vehicle and position it on a bench or clean floor for separation (see illustration).
Refitting
46 Refitting is the reverse sequence to removal, following where necessary the instructions given in the other Chapters of this manual. Note the following additional points:
a) Tighten all nuts and bolts to the specified
torque wrench settings (where given).
b) On models fitted with offset sphere inner
driveshaft joints, ensure that the joint
circlips are properly located in their
grooves, then apply a smear of graphite-
based grease to the splines, and locate
the joints in the transmission. Push them
firmly into position, and check they are
securely retained by the circlips.
c) Ensure that all wiring harnesses are
properly routed, and are retained by any
necessary cable-ties or clips.
d) On automatic transmission models, adjust
the selector cable as described in Chapter 7B, Section 6.
e) On models fitted with a vacuum servo
unit, refit the brake master cylinder as described in Chapter 9.
f) Tighten all hose clips securely, and refill
the cooling system as described in Chapter 1.
g) Fit a new oil filter and fill the engine with
fresh oil as described in Chapter 1.
h) On completion, reconnect the battery,
and adjust the accelerator cable as described in Chapter 4A or B as applicable.
4 Engine/transmission (with
front subframe) - removal and
refitting
4
Note: After disconnecting all the relevant components, the body can be lifted up at the front by four strong people and wheeled away, or the body can be lifted by block and tackle and the engine/transmission and subframe assembly rolled out from underneath. When working on cars equipped with Hydrolastic suspension, it will be necessary to have the system depressurised by a Rover dealer before commencing the removal procedure (see Chapter 10 Section 2).
Removal
1 Begin by carrying out paragraphs 1 to 24, and 27 to 33 inclusive of the previous Section, ignoring references to manual or automatic transmission where these are not applicable. 2 Refer to Chapter 4C if necessary and remove the complete exhaust system from the car. 3 Undo and remove the knurled nut securing the speedometer cable to its housing on the left-hand side of the transmission. Withdraw the cable from the housing.
2B•6 Engine removal and overhaul procedures
3.44a Lift the engine/transmission out of the engine bay . . . 3.44b . . . until sufficient clearance exists to disconnect the speedometer cable
4 Remove the brake master cylinder filler cap
and place a piece of polythene over the filler neck. Now securely refit the cap. This will help prevent loss of fluid when the hydraulic pipes are disconnected. 5 On models equipped with a single line braking system undo and remove the brake hydraulic pipe to the front wheels at the three­way connector on the bulkhead. Where a dual line or split braking system is fitted, undo and remove the hydraulic pipes to the front wheels at the pressure differential warning actuator or the pressure reducing valve according to system type. In all cases plug or tape over the pipe ends after removal to prevent dirt ingress. 6 If the brake lights are operated by a hydraulic pressure switch, disconnect the electrical leads at the switch, which is located on the right-hand side of the subframe. 7 Slacken the clip and detach the brake servo vacuum hose (where fitted) at the union on the inlet manifold. 8 On models fitted with rubber cone suspension, remove the front shock absorbers as described in Chapter 10. 9 On cars fitted with Hydrolastic suspension, undo and remove the displacer unit hoses at the transfer pipe unions. 10 Now refit the roadwheels and lower the car to the ground. 11 From inside the car lift up the carpets and undo and remove the two bolts each side securing the rear of the subframe or subframe mounting to the floor. 12 At the front of the car undo and remove the bolt that secures each side of the subframe or subframe mounting to the body. 13 On early models knock back the locking plate tabs from the two bolts (or nuts) on either side of the engine compartment which secure the subframe towers to the bulkhead crossmember. 14 Now undo and remove the bolts or nuts. On later models undo and remove the large hexagon-headed plug that is fitted in place of the early bolt or stud mounting. 15 Make a final check that all cables, pipes and hoses have been disconnected and that all removed parts are clear of the engine and subframe. 16 Support the front of the subframe and the rear of the transmission casing with blocks of wood or jacks and lift the body at the front until it is clear of the engine. Take care that all components are clear when lifting the body and ensure that the radiator matrix is not damaged. 17 Now wheel the body away from the subframe or roll the subframe out from underneath, whichever is more convenient.
Refitting
18 Refitting is the reverse sequence to removal, following where necessary the instructions given in the other Chapters of this manual. Note the following additional points:
a) Tighten all nuts and bolts to the specified
torque wrench settings (where given).
b) Ensure that all wiring harnesses are
properly routed, and are retained by any necessary cable-ties or clips.
c) Adjust the accelerator cable as described
in Chapter 4A or B as applicable.
d) On automatic transmission models, adjust
the selector cable as described in Chapter 7B, Section 6.
e) Tighten all hose clips securely, and refill
the cooling system as described in Chapter 1.
f) Fit a new oil filter and fill the engine with
fresh oil as described in Chapter 1.
g) Bleed the brake hydraulic system on
completion as described in Chapter 9. Where Hydrolastic suspension is fitted it will be necessary to have the system repressurised by a Rover dealer
5 Engine and manual
transmission - separation and
reconnection
3
Separation
1 Remove the engine/transmission assembly from the car as described in Section 3. Alternatively, if the unit has been removed complete with front subframe, undo the engine/transmission mounting attachments and lift the assembly from the subframe using suitable lifting tackle. Position the
engine/transmission on the bench and proceed as follows. 2 If not already done, drain the engine/transmission oil as described in Chapter 1. 3 Undo and remove the retaining bolts and lift off the flywheel housing cover and, if still in place, the starter motor (see illustration). 4 Where applicable, withdraw the wire retaining clips and lift away the clutch thrust plate from the centre of the diaphragm spring housing (see illustration). 5 Rotate the flywheel until the timing marks on the flywheel periphery are at approximately the 3 o’clock position. This will prevent the primary gear retaining U-shaped washer from becoming dislodged as the flywheel is removed.
Engine removal and overhaul procedures 2B•7
2B
5.3 Removing the flywheel housing cover
5.4 Clutch thrust plate and flywheel securing bolt assemblies
1 Circlip 2 Release bearing thrust
plate
3 Flywheel retaining
bolt 4 Lockwasher 5 Keyed washer
6 Using a punch or small chisel, knock back the lockwasher securing the large flywheel retaining bolt in the centre of the flywheel. 7 With a large socket and extension handle, undo and remove the flywheel retaining bolt. Insert a screwdriver between the flywheel ring gear teeth and housing to prevent the flywheel from turning while the bolt is removed. Also have an assistant support the engine, as this bolt will be tight requiring considerable leverage to remove it. When the bolt is removed, prise out the keyed locating washer from the end of the flywheel and crankshaft. 8 Where the bolt which retains the flywheel to the crankshaft has been secured with thread­locking compound or an encapsulated type of bolt is used, then prior to refitting, all threads in the crankshaft must be thoroughly cleaned. Preferably, this should be done by using a tap of the appropriate size. Discard the old retaining bolt, and use only a new encapsulated bolt incorporating a thread­locking compound patch on refitting. 9 The flywheel is a taper fit on the end of the crankshaft and a special puller will be needed to remove it. This puller is Rover special tool 18G304 and adapter 18G304M for models without the later type verto clutch assembly, or 18G1381 for models with a verto type clutch (see Chapter 6 for identification of the two clutch types, if necessary). Note that there are a number of similar pullers readily obtainable from accessory shops or tool hire outlets if the manufacturer’s tool is not available (see illustration). 10 Position the puller with the three studs or bolts inserted through the holes in the spring
housing (non-verto type) and screwed into the flywheel securely. Do not tighten the studs/ bolts or the clutch disc may be damaged. Fit the thrust pad of the puller to the end of the crankshaft and then tighten the puller centre bolt. Prevent the flywheel from turning using a screwdriver inserted into the ring gear teeth. 11 Continue tightening the centre bolt of the puller until the flywheel breaks free from the taper. It is quite likely that the flywheel will be extremely tight requiring a great deal of effort to free it. If this is the case sharply strike the puller centre bolt with a medium hammer. This should “shock” the flywheel off the taper. Take care when doing this as the flywheel may spring off and land on your feet! 12 Once the taper is released the complete clutch and flywheel assembly can be lifted off the end of the crankshaft. 13 With the flywheel and clutch removed the flywheel housing can be separated from the engine/transmission casing as follows. 14 If a breather is fitted to the top of the housing undo and remove the retaining bolts and lift off the breather assembly. 15 Knock back the tabs on the lockwashers inside the housing. 16 Undo and remove the nine nuts from the studs on the transmission casing (see
illustration). 17 Undo and remove the six bolts from the
cylinder block. Note the positions from which the shorter bolts are removed. 18 The housing can now be carefully pulled off. Note that as the housing is withdrawn a small quantity of oil will be released so have some old rags or a small container handy.
19 With the flywheel and flywheel housing removed, undo and remove the flange nuts, bolts and spring washers securing the engine to the transmission. 20 Undo and remove the bolts securing the radiator lower mounting bracket to the engine mounting bracket. 21 Using a crane, or hoist and lifting slings, carefully lift the engine off the transmission casing. It may be necessary to tap the transmission casing downwards with a rubber or hide mallet to break the seal between the two mating faces. 22 With the engine removed, cover the top of the transmission to prevent dirt ingress.
Reconnection
Note: Before reconnecting the engine and transmission, refer to Chapter 7A, Section 6 and adjust the endfloat of the transfer gears (primary gear and idler gear). Then proceed as described below.
23 Carefully scrape away any remaining traces of old gasket from the engine/transmission mating faces and flywheel housing joint. 24 Lightly smear the upper sides of the engine/transmission joint gaskets with jointing compound and place them in position on the engine mating face. 25 Apply a bead of RTV sealant to all the mating surfaces of the front oil seal, then place seal in position between the front main bearing cap and engine front plate (see illustration).
2B•8 Engine removal and overhaul procedures
5.9 Using a commercially available puller to release the flywheel taper
5.25 Fitting a new front oil seal . . .5.16 Flywheel housing attachments
26 Locate the oil supply O-ring into its
groove in the transmission casing face, and if necessary retain it in place with a trace of grease (see illustration). 27 Using suitable lifting gear and with the help of an assistant, carefully lower the engine onto the transmission casing. Have your assistant guide the engine, and lower it very slowly, as it is easy to dislodge the gaskets. 28 With the engine in position, refit and fully tighten the retaining nuts, bolts and spring washers, and refit the radiator lower mounting bolts. 29 Refit the primary gear thrustwasher to the end of the crankshaft with its chamfered side toward the crankshaft flange (see
illustration). 30 Slide on the primary gear (see illustration) and then turn the crankshaft until
No 1 piston at TDC (refer to Part A, Section 3). 31 Refit the primary gear retaining ring and then secure the assembly in position with the C-shaped washer (see illustrations). 32 Refit the idler gear to its bearings in the transmission casing, turning it slightly to mesh with the other two gears as it is installed. Ensure that both the thrustwashers are in position, one each side of the idler gear: if the later type gear is being fitted, the longer boss goes toward the transmission casing. 33 Place a new joint gasket over the studs on the transmission casing. 34 Before fitting the flywheel housing, make sure that a new flywheel housing oil seal has been fitted (see Part A, Section 9), and cover the splines of the primary gear with the
special thin sleeve of Rover special tool 18G570. Alternatively, wrap tin foil or masking tape tightly over the splines to avoid damaging the seal. Lubricate the lip of the oil seal prior to fitting. 35 Carefully refit the flywheel housing, taking care that the rollers on the first motion shaft bearing enter their outer race squarely. On no account force the housing. If it does not easily push fully home, turn the bearing slightly and try again. Two or three attempts may be needed (see illustration). 36 Refit new locking tabs, followed by the housing retaining nuts and bolts to their correct locations. Tighten the fixings to the specified torque and bend over the locktabs. 37 Carefully clean the mating tapers in the flywheel and on the end of the crankshaft, and make quite certain there are no traces of oil, grease, or dirt present. 38 Refit the flywheel on the end of the crankshaft with the 1/4 TDC markings at the top and then refit the driving washer which positively locates the flywheel. 39 Fit a new lockwasher under the head of the flywheel securing bolt. Remember to use only a new encapsulated bolt incorporating a thread­locking compound if that type of bolt was removed. Insert the bolt in the centre of the flywheel and tighten it to the specified torque. 40 Tap down the side of the lockwasher against the driving plate, and tap up the other side of the washer against the retaining bolt head. 41 Refit the thrust plate and secure it in position with the circular retaining spring.
42 Now refit the flywheel housing cover and fully tighten the retaining bolts. Refit the starter motor if appropriate at this stage.
6 Engine and automatic
transmission - separation and
reconnection
3
Separation
1 Remove the engine/transmission assembly from the car as described in Section 3. Alternatively, if the unit has been removed complete with front subframe, undo the engine/transmission mounting attachments and lift the assembly from the subframe using suitable lifting tackle. Position the engine/ transmission on the bench and proceed as follows. 2 If not already done, drain the engine/ transmission oil as described in Chapter 1. 3 Undo and remove the retaining bolts and lift off the torque converter housing cover and, if still in place, the starter motor. 4 Undo and remove the retaining nuts and bolts and take off the converter housing cover. 5 Undo and remove the five retaining bolts and lift off the low pressure valve assembly from its location beneath the torque converter
(see illustration). 6 Using a socket and bar, undo and remove
the converter input gear retaining nut. Use a large screwdriver inserted through the hole in the top of the converter housing and engaged with the ring gear teeth to prevent the torque converter from turning.
Engine removal and overhaul procedures 2B•9
2B
5.26 . . . and a new O-ring to the transmission casing joint face
5.29 Position the primary gear
thrustwasher on the crankshaft
5.30 Slide on the primary gear . . .
5.31a . . . followed by the retaining ring . . . 5.31b . . . and the C-shaped washer 5.35 Refitting the flywheel housing
7 Knock back the locktabs, and undo and
remove three equally spaced bolts from the centre of the converter. Leave the other three bolts in position. 8 Knock back the lockwasher securing the large converter centre retaining bolt. Using a large socket and bar, undo and remove the torque converter centre bolt. Use a screwdriver as previously described to prevent the converter from turning. 9 Rotate the crankshaft until the timing marks on the converter periphery are at approximately the 3 o’clock position. 10 The torque converter is a taper fit on the end of the crankshaft and it will be necessary to obtain Rover special tool 18G1086 to remove it. The tool is bolted to the torque converter through the holes of the three previously removed converter retaining bolts. With the adapter in position on the end of the crankshaft, tighten the tool centre bolt until the torque converter breaks free of the taper, and then lift it off the crankshaft. 11 Undo and remove the nuts, bolts and washers securing the converter housing to the engine and transmission casing. 12 Remove the selector bellcrank lever clevis pin and nut, and lift off the bellcrank lever. Remove the bellcrank lever pivot. 13 The converter housing can now be carefully withdrawn.
14 With the torque converter and housing removed, carefully lever the main oil feed pipe from the transmission and oil pump (see
illustration). 15 Undo and remove the two retaining bolts
and lift off the oil filter and housing assembly. 16 Unscrew the engine oil feed pipe union at the adapter on the transmission casing. 17 Undo and remove the flange nuts, bolts and spring washers securing the engine to the transmission. 18 Undo and remove the bolts securing the radiator lower mounting bracket to the engine mounting adapter. 19 Using a crane, or hoist and lifting slings, carefully lift the engine off the transmission casing. It may be necessary to tap the transmission casing downward with a rubber or hide mallet to break the seal between the two mating faces. 20 With the engine removed cover the top of the transmission completely to prevent dirt ingress.
Reconnection
Note: Before reconnecting the engine and transmission, the endfloat of the transfer gears (primary gear and idler gear) must be adjusted. The procedure is the same as for manual transmission models and is described in Chapter 7A, Section 6. With the endfloat adjusted, proceed as described below.
21 Carefully scrape away any remaining traces of old gasket from the engine/transmission mating faces and flywheel housing joint. 22 Lightly smear the upper sides of the engine/transmission joint gaskets with jointing compound and place them in position on the engine mating face. 23 Apply a bead of RTV sealant to all the mating surfaces of the front oil seal, then place seal in position between the front main bearing cap and engine front plate. 24 Using suitable lifting gear and with the help of an assistant, carefully lower the engine onto the transmission casing. Have your assistant guide the engine, and lower it very slowly, as it is easy to dislodge the gaskets. 25 With the engine in position, refit and fully tighten the retaining nuts, bolts and spring washers, and refit the radiator lower mounting bolts. 26 Refit the engine oil feed pipe to the union on the transmission casing. 27 Place a new gasket in position and refit the oil filter assembly. 28 Using new O-rings where necessary, carefully push the oil feed pipe into engagement with the oil pump and transmission casing orifice. 29 Place the converter output gear thrustwasher over the end of the crankshaft, with its chamfered face toward the crankshaft flange.
2B•10 Engine removal and overhaul procedures
6.5 Low pressure valve assembly and input gear retaining nut ­automatic transmission models
6.14 End view of the automatic transmission transfer gears with the converter housing removed
1 Main oil pump 2 Converter output gear 3 Idler gear
4 Input gear 5 Oil feed pipe 6 Sealing rings
30 Now slide on the output gear. Turn the crankshaft until No 1 piston is at TDC (refer to Part A, Section 3) then refit the output gear retaining ring and C-shaped washer. 31 With the thrustwashers located over each side of the idler gear, insert the gear into its needle roller bearing. 32 Ensure that the mating faces of the engine/transmission and converter housing are clean, and then position a new gasket over the studs on the transmission. 33 Before fitting the converter housing, make sure that a new converter housing oil seal has been fitted (see Part A, Section 9), and cover the splines of the converter output gear with the special thin sleeve of Rover special tool 18G1098. Alternatively, wrap tin foil or masking tape tightly over the splines to avoid damaging the seal. Lubricate the lip of the oil seal prior to fitting. 34 Now carefully refit the converter housing, pushing it squarely home over the transmission casting studs. Refit the retaining nuts and bolts, tightened to the specified torque. 35 Refit the selector bellcrank lever pivot, lever, clevis pin and nut. 36 Before fitting the torque converter, it will be first necessary to refit the three central bolts removed to allow the special converter removal tool to be used during dismantling. Then remove each pair of bolts in turn from the converter centre and fit new locking plates. Tighten the six bolts to the specified torque wrench setting and bend over the lock tabs. On no account remove all six bolts at any one time. Then, with No 1 and 4 pistons still at the TDC position, slide the torque converter onto the end of the crankshaft, with the timing marks uppermost. Refit the driving collar, a new lockwasher and the retaining bolt. Tighten the retaining bolt to the torque given in the Specifications, and then knock back the lockwasher. 37 Now refit and fully tighten the input gear retaining nut. 38 Position a new gasket on the transmission casing and refit the low pressure valve assembly. 39 Finally refit the converter housing cover and the starter motor.
7 Engine overhaul - preliminary
information
It is much easier to dismantle and work on the engine if it is mounted on a portable engine stand. These stands can often be hired from a tool hire shop.
If a stand is not available, it is possible to dismantle the engine with it suitably supported on a sturdy, workbench or on the floor. Be careful not to tip or drop the engine when working without a stand.
If you intend to obtain a reconditioned engine, all ancillaries must be removed first, to be transferred to the replacement engine (just as they will if you are doing a complete engine overhaul yourself). These components include the following:
a) Dynamo/alternator mounting brackets. b) Engine/transmission mountings and
brackets (Part A of this Chapter).
c) Tappet block side covers - where fitted
(Section 9).
d) The ignition system and HT components
including all sensors, distributor cap and rotor arm, HT leads and spark plugs
(Chapters 1 and 5B). e) Distributor driveshaft (Part A of this Chapter). f) All electrical switches and sensors. g) Emission control equipment - where
applicable (Chapter 4C). h) Thermostat and housing, water pump,
heater control valve (Chapter 3). i) Mechanical fuel pump - carburettor
engines only (Chapter 4A). j) Carburettor/fuel injection system
components (Chapter 4A and 4B). k) Inlet and exhaust manifolds (Chapter 4A,
4B and 4C). l) Oil pump (Section 10). m)Oil filter housing and delivery pipe (Part A
of this Chapter). n) Oil filter (Chapter 1).
Note: When removing the external components from the engine, pay close attention to details that may be helpful or important during refitting. Note the fitting positions of gaskets, seals, washers, bolts and other small items.
If you are obtaining a “short” engine (cylinder block, crankshaft, pistons, camshaft and tappets, and connecting rods all assembled), then the cylinder head, timing chain (together with tensioner, sprockets and cover) will have to be removed also.
If a complete overhaul is planned, the engine can be dismantled in the order given below, referring to Part A of this Chapter unless otherwise stated.
a) Inlet and exhaust manifolds (Chapter 4A
or 4B). b) Distributor driveshaft. c) Timing chain, sprockets and tensioner. d) Cylinder head. e) Camshaft and tappets (Section 9). f) Oil pressure relief valve. g) Oil filter housing and delivery pipe. h) Oil pump (Section 10). i) Piston/connecting rod assemblies
(Section 11). j) Crankshaft (Section 12).
8 Cylinder head - dismantling,
cleaning, inspection and reassembly
3
Note: New and reconditioned cylinder heads are available from the manufacturer, and from engine overhaul specialists. Be aware that some specialist tools are required for the dismantling and inspection procedures, and new components may not be readily available. It may therefore be more practical and economical for the home mechanic to purchase a reconditioned head, rather than dismantle, inspect and recondition the original head.
Dismantling
1 Remove the cylinder head as described in Part A of this Chapter. 2 If not already done, remove the inlet and exhaust manifolds with reference to the relevant Part of Chapter 4. 3 With a pair of pliers remove the spring clips (where fitted) holding the two halves of the split collets together. 4 Using a valve spring compressor, compress each valve spring in turn until the split collets can be removed. Release the compressor, and lift off the spring retainer, valve guide shield (early models) and the spring. Where fitted, slide the oil seal off the valve stem.
Note: On 1275 cc engines the oil seal is positioned over the valve guide. On Cooper S models double valve springs are used. (see
illustrations).
Engine removal and overhaul procedures 2B•11
2B
8.4a Compress the valve springs with a spring compressor and lift off the split
collets . . .
8.4b . . . Then remove the compressor, valve cap and spring
If, when the valve spring compressor is screwed down, the spring retainer
refuses to free and expose the split collets, gently tap the top of the tool, directly over the retainer, with a light hammer. This will free the retainer.
5 Withdraw the valve through the combustion chamber. 6 It is essential that each valve is stored together with its collets, retainer and spring(s). The valves should also be kept in their correct sequence, unless they are so badly worn that they are to be renewed. If they are going to be kept and used again, place each valve assembly in a labelled polythene bag or similar small container (see illustration). Note that No 1 valve is nearest to the timing chain end of the engine.
Cleaning
7 Thoroughly clean all traces of old gasket material and sealing compound from the cylinder head mating surfaces. Use a suitable cleaning agent together with a putty knife or scraper, taking care not to scratch the head surface.
8 Remove the carbon from the combustion chambers and ports, then clean all traces of oil and other deposits from the cylinder head, paying particular attention to the valve guides and oilways. 9 Wash the head thoroughly with paraffin or a suitable solvent. Take plenty of time and do a thorough job. Be sure to clean all oil holes and galleries very thoroughly, dry the head completely and coat all machined surfaces with light oil. 10 Scrape off any heavy carbon deposits that may have formed on the valves, then use a power-operated wire brush to remove deposits from the valve heads and stems.
Inspection
Note: Be sure to perform all the following inspection procedures before concluding that the services of an engineering works are required. Make a list of all items that require attention.
Cylinder head
11 Inspect the head very carefully for cracks,
evidence of coolant leakage, and other damage. If cracks are found, a new cylinder head should be obtained. 12 Use a straight-edge and feeler blade to check that the cylinder head gasket surface is not distorted. If it is, it may be possible to have it machined. Seek the advice of a Rover dealer or engine overhaul specialist if distortion is suspected. 13 Examine the valve seats in each of the combustion chambers. If they are severely
pitted, cracked, or burned, they will need to be renewed or re-cut by an engine overhaul specialist. If they are only slightly pitted, this can be removed by grinding-in the valve heads and seats with fine valve-grinding compound, as described below. 14 Check the valve guides for wear by inserting the relevant valve, and checking for side-to-side motion of the valve. A very small amount of movement is acceptable. If the movement seems excessive, remove the valve. Measure the valve stem diameter (see below), and renew the valve if it is worn. If the valve stem is not worn, the wear must be in the valve guide, and the guide must be renewed. The renewal of valve guides is best carried out by a Rover dealer or engine overhaul specialist, who will have the necessary tools available. 15 If renewing the valve guides, the valve seats should be re-cut or re-ground only after the guides have been fitted.
Valves
16 Examine the head of each valve for
pitting, burning, cracks, and general wear. Check the valve stem for scoring and wear ridges. Rotate the valve, and check for any obvious indication that it is bent. Look for pits or excessive wear on the tip of each valve stem. Renew any valve that shows any such signs of wear or damage. 17 If the valve appears satisfactory at this stage, measure the valve stem diameter at several points using a micrometer (see illustration). Any significant difference in the readings obtained indicates wear of the valve stem. Should any of these conditions be apparent, the valve(s) must be renewed. 18 In order to reduce oil consumption, valve stem oil seals are fitted to the inlet valves of later 998 cc engines. Fitting of the seals has required the incorporation of modified valves, with cotter grooves nearer the end of the stem. The valve spring seats have also been raised by 1.2 mm. 19 If renewing any valves, bear in mind that new type valves and seals can be fitted to old type cylinder heads in complete sets only, with the addition of a shim 1.2 mm thick underneath each spring. These shims may also be found already fitted to engines which left the factory with the new type valves and
2B•12 Engine removal and overhaul procedures
8.6 Keep all valve components together in a labelled plastic bag
8.17 Measuring the valve stem diameter
8.4c Valve assembly components
1 Early type 2 Later type 3 Cooper S type
seals in unmodified heads. Consult a Rover dealer for further details of this modification. 20 If the valves are in satisfactory condition, they should be ground (lapped) into their respective seats, to ensure a smooth, gas­tight seal. If the seat is only lightly pitted, or if it has been re-cut, fine grinding compound only should be used to produce the required finish. Coarse valve-grinding compound should not be used, unless a seat is badly burned or deeply pitted. If this is the case, the cylinder head and valves should be inspected by an expert, to decide whether seat re­cutting, or even the renewal of the valve or seat insert (where possible) is required. 21 Valve grinding is carried out as follows. Place the cylinder head upside-down on a bench. 22 Smear a trace of (the appropriate grade of) valve-grinding compound on the seat face, and press a suction grinding tool onto the valve head. With a semi-rotary action, grind the valve head to its seat, lifting the valve occasionally to redistribute the grinding compound. A light spring placed under the valve head will greatly ease this operation. 23 If coarse grinding compound is being used, work only until a dull, matt even surface is produced on both the valve seat and the valve, then wipe off the used compound, and repeat the process with fine compound. When a smooth unbroken ring of light grey matt finish is produced on both the valve and seat, the grinding operation is complete. Do not grind-in the valves any further than absolutely necessary, or the seat will be prematurely sunk into the cylinder head.
24 When all the valves have been ground-in, carefully wash off all traces of grinding compound using paraffin or a suitable solvent, before reassembling the cylinder head.
Valve components
25 Examine the valve springs for signs of
damage and discoloration. Measure their free length and compare the dimension with the figures given in the Specifications (see
illustration). 26 Stand each spring on a flat surface, and
check it for squareness. If any of the springs are damaged, distorted or shorter than the specified length, obtain a complete new set of springs. It is normal to renew the valve springs as a matter of course if a major overhaul is being carried out. 27 Renew the valve stem oil seals regardless of their apparent condition.
Reassembly
28 Lubricate the stems of the valves, and insert the valves into their original locations. If new valves are being fitted, insert them into the locations to which they have been ground. 29 As each valve is inserted, slip the oil seal into place just under the bottom of the collet groove. A much larger oil seal is used on the 1275 cc engines. This should be fitted over the top of the valve guide. 30 Refit the valve spring(s), valve guide shield (early models) and the spring retainer. 31 Compress the valve spring, and locate the split collets in the recess in the valve stem. Release the compressor, then repeat the procedure on the remaining valves.
32 With all the valves installed, place the cylinder head face down on blocks on the bench and, using a hammer and interposed block of wood, tap the end of each valve stem to settle the components. 33 The cylinder head can then be refitted as described in Part A of this Chapter.
9 Camshaft and tappets -
removal, inspection and refitting
3
Note: The camshaft can only be removed with the engine out of the car and on the bench. With the cylinder head, timing cover, gears and chain, fuel pump and distributor drivegear removed, proceed as follows.
Removal
1 On 848, 998 and 1098 cc engines, undo and remove the bolt securing each tappet block side cover to the rear of the cylinder block and lift off the covers (see illustration). 2 Lift out each tappet from its location in the cylinder block and ensure that they are kept in the correct sequence in which they were removed (see illustration). Note: On 1275 cc
engines, tappet block side covers are not fitted and the tappets can only be removed after removing the camshaft.
3 Undo and remove the three bolts and spring washers securing the camshaft locating plate to the cylinder block. Lift off the plate (see illustration). 4 On 848, 998 and 1098 cc engines, carefully withdraw the camshaft from the cylinder block, taking care not to damage the camshaft bearings with the cam lobes as it is withdrawn. 5 On 1275 cc engines position the engine on its side to prevent the tappets falling out, then slide out the camshaft. Recover the oil pump drive coupling from the end of the camshaft after removal. Now lift out each tappet, from inside the crankcase, keeping them in the correct sequence in which they were removed. 6 On all engines, if further dismantling is to be carried out, undo the bolts still remaining and lift off the engine front plate. Recover the gasket and clean the mating surfaces of the front plate and cylinder block.
Inspection
Camshaft and camshaft bearings
7 Carefully examine the camshaft bearings
for wear. Note: On 848 cc engines, only the front camshaft bearing is renewable. If the
bearings are obviously worn or pitted or the
Engine removal and overhaul procedures 2B•13
2B
8.25 Measuring valve spring free length
9.1 Removing the tappet side covers 9.2 Removing the cam followers 9.3 Undo the camshaft locating plate bolts and lift off the plate
Use a little dab of grease to hold the collets in position on the valve stem while the spring compressor is released.
metal underlay is showing through, then they must be renewed (where applicable). This operation must be entrusted to a Rover dealer or engine reconditioning specialist as it demands the use of specialised equipment. The bearings are removed with a special drift, after which new bearings are pressed in, care being taken to ensure that the oil holes in the bearings line up with those in the block. With a special tool the bearings are then reamed in position. 8 The camshaft itself should show no signs of wear, but if very slight scoring on the cam lobes is noticed, the score marks can be removed by very gentle rubbing down with very fine emery cloth. The greatest care should be taken to keep the cam profiles smooth.
Tappets
9 Examine the bearing surface of the tappets
which contact the camshaft lobes. Any indentation in this surface or any cracks indicate serious wear and the tappets should be renewed. Thoroughly clean them out, removing all traces of sludge. It is most unlikely that the sides of the tappets will prove worn, but, if they are a very loose fit in their bores and can readily be rocked, they should be renewed. It is very unusual to find any wear in the tappets, and any wear present is likely to occur only at very high mileage.
Refitting
10 On 1275 cc engines, generously lubricate the tappets internally and externally, and insert them in the bores from which they were removed. 11 Wipe the camshaft bearing journals clean and lubricate them generously with engine oil. 12 Insert the camshaft into the cylinder block, taking care not to damage the camshaft bearings with the sharp edges of the cam lobes. 13 Push the camshaft back as far as it will go
and, if the oil pump is in position, ensure that the camshaft flange has mated with the pump drive. 14 Place a new gasket in position and refit the front plate (if previously removed). 15 Now refit the camshaft locating plate and tighten the three retaining bolts. Temporarily refit the camshaft sprocket, then check the camshaft endfloat, referring to the figures given in the Specifications. 16 Refit the remaining front plate bolts located inside the timing cover profile. 17 On 848, 998 and 1098 cc engines, refit the tappet block side covers using new gaskets and secure with the retaining bolts.
10 Oil pump - removal,
inspection and refitting
3
Removal
Note: Prior to removing the pump, it will be necessary to remove the flywheel and flywheel housing, or torque converter and housing. The oil pump engages directly via a lip and slot or splined drive with the rear of the camshaft.
1 Bend back the locking tabs on the securing bolts which hold the pump to the block. 2 Unscrew and remove the bolts and lock tabs, then lift off the oil pump assembly.
Inspection
Note: Three types of oil pump have been fitted during the course of production; these are the Burman, Hobourn Eaton, and the Concentric (Engineering) pumps. The Burman and Hobourn Eaton pumps may be dismantled for inspection as described below; however the Concentric (Engineering) pump is a sealed unit which cannot be dismantled, and if suspect should be exchanged for a new unit. It is quite likely that after high mileage the rotor, (or vanes), shaft, and internal body of
the pump will be quite badly scored, requiring renewal of the pump. This is mainly due to the engine and transmission sharing the same lubricating oil, making thorough filtration of minute metallic particles impossible. It is therefore recommended that a very careful inspection of the pump be carried out and, if at all suspect, the pump renewed.
3 To dismantle either the Burman or Hobourn Eaton type of pump, undo and remove the securing screw on the rear face and lift off the cover, rotor and shaft. 4 Examine the rotor and shaft lobes (or vanes on the Burman pump) for scoring or wear ridges. Also check the inner circumference of the pump body. Renew the complete pump if wear is apparent. 5 If the pump is in a satisfactory condition, measure the clearances between the shaft lobes and the side of the pump body (see illustrations). If the clearances are outside the limits given in the Specifications the pump must be renewed. 6 Reassembly of the pump is the reverse sequence to dismantling. Fill the assembled pump with clean engine oil before refitting to the engine.
Refitting
7 Ensure that the pump and cylinder block mating faces are clean then place a new gasket in position on the rear face of the block. 8 Check that the pump is filled with clean engine oil and then position it over the gasket, engaging the drive slot or coupling with the rear of the camshaft. 9 Rotate the pump body until the offset holes in the pump, gasket and cylinder block are all in line, then refit the retaining bolts and new locktabs. 10 Tighten the bolts to the specified torque and bend over the locktabs.
2B•14 Engine removal and overhaul procedures
10.5a Measuring the oil pump rotor lobe clearance . . . 10.5b . . . and rotor-to-body clearance
11 Piston/connecting rod -
removal, inspection, separation and reconnection
3
Removal
1 With the engine separated from the transmission and the cylinder head removed, the piston/connecting rod assemblies can be removed as follows. 2 Knock back the locking tabs on the big-end bearing cap retaining bolts, using a small chisel and remove the bolts and locking tabs. The 1275 cc engine does not have locking tabs and the big-end caps are retained by bolts and special multi-sided nuts. 3 Remove the big-end caps one at a time, taking care to keep them in the right order and the correct way round (see illustration). Also ensure that the shell bearings are kept with their correct connecting rods and caps unless they are to be renewed. Normally, the numbers 1 to 4 are stamped on adjacent sides of the big-end caps and connecting rods, indicating which cap fits on which rod and which way round that cap fits. If no numbers or lines can be found then, with a sharp screwdriver, scratch mating marks across the joint from the rod to the cap. One line for connecting rod No 1, two for connecting rod No 2, and so on. This will ensure that there is no confusion later, as it is essential that the caps go back in the correct position on the connecting rods from which they were removed. 4 If the big-end caps are difficult to remove they may be gently tapped with a soft mallet. 5 To remove the shell bearings, press the bearing opposite the groove in both the connecting rod and the connecting rod caps, and the bearings will slide out easily. 6 Withdraw the pistons and connecting rods upwards and ensure that they are kept in the correct order for refitting in the same bore. Refit the connecting rod caps and bearings to the rods if the bearings do not require renewal, to minimise the risk of getting the caps and rods muddled.
Inspection
7 Before the inspection process can begin, the piston/connecting rod assemblies must
be cleaned, and the original piston rings removed from the pistons. 8 Carefully expand the old rings over the top of the pistons. The use of two or three old feeler blades will be helpful in preventing the rings dropping into empty grooves (see illustration). Be careful not to scratch the piston with the ends of the ring. The rings are brittle, and will snap if they are spread too far. They are also very sharp - protect your hands and fingers. Always remove the rings from the top of the piston. Keep each set of rings with its piston if the old rings are to be re-used. 9 Scrape away all traces of carbon from the top of the piston. A hand-held wire brush (or a piece of fine emery cloth) can be used, once the majority of the deposits have been scraped away. 10 Remove the carbon from the ring grooves in the piston, using an old ring. Break the ring in half to do this (be careful not to cut your fingers - piston rings are sharp). Be careful to remove only the carbon deposits - do not remove any metal, and do not nick or scratch the sides of the ring grooves. 11 Once the deposits have been removed, clean the piston/connecting rod assembly with paraffin or a suitable solvent, and dry thoroughly. Make sure that the oil return holes in the ring grooves are clear. 12 If the pistons and cylinder bores are not damaged or worn excessively, the original pistons can be refitted. Normal piston wear shows up as even vertical wear on the piston thrust surfaces, and slight looseness of the top ring in its groove. New piston rings should always be used when the engine is reassembled. 13 Carefully inspect each piston for cracks around the skirt, around the gudgeon pin holes, and at the piston ring “lands” (between the ring grooves). 14 Look for scoring and scuffing on the piston skirt, holes in the piston crown, and burned areas at the edge of the crown. If the skirt is scored or scuffed, the engine may have been suffering from overheating, and/or abnormal combustion which caused excessively high operating temperatures. The cooling and lubrication systems should be checked thoroughly. Scorch marks on the sides of the pistons show that blow-by has occurred. A
hole in the piston crown, or burned areas at the edge of the piston crown, indicates that abnormal combustion (pre-ignition, knocking, or detonation) has been occurring. If any of the above problems exist, the causes must be investigated and corrected, or the damage will occur again. The causes may include incorrect ignition timing, or a carburettor or fuel injection system fault. 15 Corrosion of the piston, in the form of pitting, indicates that coolant has been leaking into the combustion chamber and/or the crankcase. Again, the cause must be corrected, or the problem may persist in the rebuilt engine. 16 Using a micrometer, measure the diameter of all four pistons at a point 10 mm from the bottom of the skirt, at right angles to the gudgeon pin axis (see illustration). Record the measurements and use them to check the piston-to-bore clearance when the cylinder bores are measured later in this Chapter. 17 Hold a new piston ring in the appropriate groove and measure the ring-to-groove clearance using a feeler blade (see illustration). Note that the rings are of different types, so use the correct ring for the groove. Compare the measurements with those listed in the Specifications; if the clearances are outside the tolerance range, then the pistons must be renewed. 18 When new pistons are to be fitted, take great care to be sure to fit the exact size best suited to the particular bore of your engine. Rover go one stage further than merely specifying one size piston for all standard
Engine removal and overhaul procedures 2B•15
2B
11.3 Removing a connecting rod big-end cap
11.8 Using feeler blades to aid removal of the piston rings
11.16 Measuring the piston diameter
11.17 Measuring the piston ring-to-groove clearance
bores. Because of very slight differences in cylinder machining during production, it is necessary to select just the right piston for the bore. A range of different sizes are available either from the piston manufacturer or from a Rover dealer. 19 Examination of the cylinder block face will show, adjacent to each bore, a small diamond-shaped box with a number stamped in the metal. Careful examination of the piston crown will show a matching diamond and number (see illustration). These are the standard piston sizes and will be the same for all bores. If the standard pistons are to be refitted or standard low compression pistons changed to standard high compression pistons, then it is essential that only pistons with the same number in the diamond are used. With oversize pistons fitted after a rebore, the amount of oversize is stamped in an ellipse on the piston crown. 20 Examine each connecting rod carefully for signs of damage, such as cracks around the big-end and small-end bearings. Check that the rod is not visibly bent or distorted. Damage is highly unlikely, unless the engine has been seized or badly overheated. Detailed checking of the connecting rod assembly can only be carried out by a Rover dealer or engine repair specialist with the necessary equipment.
Separation
21 Three different methods of gudgeon pin retention are employed, depending on the type and cubic capacity of the engine. 22 On the 848 cc engines the gudgeon pin is clamped firmly in place by a pinch-bolt located in the end of the connecting rod (see illustration). To remove the piston from the connecting rod it is merely necessary to undo and remove the pinch-bolt and slide out the gudgeon pin. If it shows reluctance to move, do not force it as this may damage the piston. Immerse the piston in boiling water for a few minutes; the expansion of the aluminium should allow the pin to slide out easily. 23 On early 998 cc and all 1098 cc engines, fully floating gudgeon pins are used, these being retained in position by a circlip at each end of the gudgeon pin bore in the piston. To remove the gudgeon pin and piston, withdraw the circlip from one end and push the pin out,
immersing it in boiling water if it appears reluctant to move. 24 On later 998 cc and all 1275 cc engines the gudgeon pin is firmly held in the small-end of the connecting rod by an interference fit. Removal of the gudgeon pin calls for the use special tools and a good deal of experience to use them correctly. Therefore, piston and/or connecting rod renewal should be entrusted to a Rover dealer or engine repair specialist, who will have the necessary tooling to remove and install the gudgeon pins. 25 On early 998 cc and all 1098 cc engines, check the fit of the gudgeon pin in the connecting rod bush and in the piston. If there is perceptible play, a new bush or an oversize gudgeon pin must be fitted. Consult a Rover dealer or engine reconditioning specialist. 26 Examine all components and obtain any new parts required. If new pistons are purchased, they will be supplied complete with gudgeon pins and, where applicable, circlips. Circlips can also be purchased separately.
Reconnection
27 If the original pistons are being used, then they must be mated to the original connecting rod with the original gudgeon pin. If new pistons and gudgeon pins are being fitted, it does not matter which connecting rod they are used with. 28 The gudgeon pin may be a very tight fit in the piston when cold (particularly on pistons which have a small-end clamp bolt) but, because aluminium has a greater coefficient of expansion than steel, this fit will be much easier if the piston is heated in boiling water. 29 Lay the correct piston adjacent to its connecting rod and remember that the original rod and piston must go back into the original bore. If new pistons are being used, it is only necessary to ensure that the right connecting rod is placed in each bore.
Gudgeon pins retained by clamp bolts
30 Locate the small-end of the connecting
rod in the piston with the marking “FRONT” on the piston crown towards the front of the engine and the hole for the gudgeon pin bolt in the connecting rod towards the camshaft. 31 Note the indentation in the centre of the gudgeon pin, and insert the pin in the
connecting rod, so that the indentation lines up with the clamp bolt hole in such a way that the bolt will pass through without touching the gudgeon pin. 32 For the gudgeon pin to fit correctly, it should slide in three quarters of its travel quite freely and for the remaining quarter have to be tapped in with a plastic or wooden headed hammer. If the piston is heated in water then the pin will slide in the remaining quarter easily. 33 Fit a new spring washer under the head of the connecting rod bolt and secure it into position to the specified torque. Repeat this procedure for the remaining pistons and connecting rods.
Fully floating gudgeon pins
34 Fit a gudgeon pin circlip in position at one
end of the gudgeon pin hole in the piston. 35 Locate the connecting rod in the piston with the marking “FRONT” on the piston crown towards the front of the engine, and the connecting rod big-end caps towards the camshaft side of the engine. 36 Slide the gudgeon pin in through the hole in the piston and through the connecting rod small-end until it rests against the previously fitted circlip. Note that the pin should be a push fit. 37 Fit the second circlip in position. Repeat this procedure for the remaining pistons and connecting rods.
Interference fit gudgeon pins
38 As stated previously, removal and refitting
of the gudgeon pin on these engines is a delicate operation requiring the use of special tools. This task must be entrusted to a Rover dealer or engine repair specialist.
12 Crankshaft - removal and
inspection
3
Removal
1 With reference to Part A of this Chapter, and earlier Sections of this Part as applicable, carry out the following:
a) Separate the engine from the
transmission. b) Remove the cylinder head. c) Remove the piston/connecting rod
assemblies. d) Remove the timing cover, chain, tensioner
and sprockets. e) Remove the camshaft locating plate and
engine front plate.
Note: If no work is to be done on the pistons and connecting rods, then removal of the cylinder head and pistons will not be necessary. Instead, after disconnecting the connecting rods from the crankshaft, the pistons need only be pushed far enough up the bores so that they are positioned clear of the crankpins.
2B•16 Engine removal and overhaul procedures
11.19 Identification markings on the piston crown
11.22 Gudgeon pin clamped in place by a pinch-bolt (848 cc)
2 Before removing the crankshaft it is
advisable to check the endfloat using a dial gauge in contact with the end of the crankshaft. Push the crankshaft fully one way, and then zero the gauge. Push the crankshaft fully the other way, and check the endfloat. The result can be compared with the specified amount, and will give an indication as to whether new thrustwashers are required. 3 If a dial gauge is not available, feeler blades can be used. First push the crankshaft fully towards the flywheel end of the engine, then use feeler blades to measure the gap between the web of the crankpin and the thrustwasher
(see illustration). 4 If identification marks are not present on
the main bearing caps, mark them suitably so that they may be refitted in their original positions and the correct way round. 5 Release the locktabs from the six bolts which hold the three main bearing caps in place. Note that locktabs are not used on 1275 cc engines. 6 Unscrew the bolts and remove them together with the locktabs. 7 Remove the main bearing caps and the bottom half of each bearing shell, taking care to keep the bearing shells in the right caps. 8 When removing the centre bearing cap, note the bottom semi-circular halves of the thrustwashers - one half lying on each side of the main bearing. Lay them with the centre bearing along the correct side (see
illustration). 9 Slightly rotate the crankshaft to free the
upper halves of the bearing shells and thrustwashers, which should now be extracted and placed over the correct bearing cap. 10 Remove the crankshaft by lifting it away from the crankcase (see illustration).
Inspection
11 Clean the crankshaft using paraffin or a suitable solvent, and dry it, preferably with compressed air if available. Be sure to clean the oil holes with a pipe cleaner or similar probe, to ensure that they are not obstructed.
Warning: Wear eye protection when using compressed air!
12 Check the main and big-end bearing journals for uneven wear, scoring, pitting and cracking. 13 Big-end bearing wear is accompanied by distinct metallic knocking when the engine is running (particularly noticeable when the engine is pulling from low speed) and some loss of oil pressure. 14 Main bearing wear is accompanied by severe engine vibration and rumble - getting progressively worse as engine speed increases - and again by loss of oil pressure. 15 Check the bearing journal for roughness by running a finger lightly over the bearing surface. Any roughness (which will be accompanied by obvious bearing wear)
indicates that the crankshaft requires regrinding (where possible) or renewal. 16 If the crankshaft has been reground, check for burrs around the crankshaft oil holes (the holes are usually chamfered, so burrs should not be a problem unless regrinding has been carried out carelessly). Remove any burrs with a fine file or scraper, and thoroughly clean the oil holes as described previously. 17 Using a micrometer, measure the diameter of the main and big-end bearing journals, and compare the results with the Specifications (see illustration). By measuring the diameter at a number of points around each journal’s circumference, you will be able to determine whether or not the journal is out-of-round. Take the measurement at each end of the journal, near the webs, to determine if the journal is tapered. No actual figures are quoted by the manufacturer for crankshaft journal ovality or taper but a figure of 0.025 mm should be considered the maximum acceptable for an engine of this type. If in doubt, seek the advice of a Rover dealer or engine specialist. 18 Check the oil seal contact surfaces at each end of the crankshaft for wear and damage. If the seal has worn a deep groove in the surface of the crankshaft, consult an engine overhaul specialist; repair may be possible, but otherwise a new crankshaft will be required. 19 If the crankshaft journals have not been reground to their minimum regrind diameter, it may be possible to have the crankshaft reconditioned, and to fit oversize bearing
shells (see Section 14). If the crankshaft has worn beyond the specified limits, it will have to be renewed. Consult your Rover dealer or engine specialist as to the best course of action.
13 Cylinder block/crankcase -
cleaning and inspection
3
Cleaning
1 Remove all external components and electrical switches/sensors from the block. 2 Scrape all traces of gasket from the cylinder block/crankcase, taking care not to damage the gasket/sealing surfaces. 3 Remove all oil gallery plugs (where fitted). The plugs are usually very tight - they may have to be drilled out, and the holes re­tapped. Use new plugs when the engine is reassembled. 4 If the block is extremely dirty, it should be steam-cleaned. 5 After the block is returned, clean all oil holes and oil galleries one more time. Flush all internal passages with warm water until the water runs clear. Dry thoroughly, and apply a light film of oil to all mating surfaces, to prevent rusting., also oil the cylinder bores. If you have access to compressed air, use it to speed up the drying process, and to blow out all the oil holes and galleries.
Warning: Wear eye protection when using compressed air!
Engine removal and overhaul procedures 2B•17
2B
12.3 Checking crankshaft endfloat using
feeler blades
12.8 Main bearing cap with thrustwashers in position
12.10 Carefully lift out the crankshaft 12.17 Use a micrometer to measure the crankshaft bearing journal diameters
6 If the cylinder block is not very dirty, you
can do an adequate cleaning job with hot (as hot as you can stand!), soapy water and a stiff brush. Take plenty of time, and do a thorough job. Regardless of the cleaning method used, be sure to clean all oil holes and galleries very thoroughly, and to dry all components well. Protect the cylinder bores as described above, to prevent rusting. 7 All threaded holes must be clean, to ensure accurate torque readings during reassembly. To clean the threads, run the correct-size tap into each of the holes to remove rust, corrosion, thread sealant or sludge, and to restore damaged threads (see illustration). If possible, use compressed air to clear the holes of debris produced by this operation. 8 Apply suitable sealant to the new oil gallery plugs, and insert them into the holes in the block. Tighten them securely. 9 If the engine is not going to be reassembled right away, cover it with a large plastic bag to keep it clean; protect all mating surfaces and the cylinder bores as described above, to prevent rusting.
Inspection
10 Visually check the castings for cracks and corrosion. Look for stripped threads in the threaded holes. If there has been any history of internal water leakage, it may be worthwhile having an engine overhaul specialist check the cylinder block/crankcase with special equipment. If defects are found, have them repaired if possible, or renew the assembly. 11 Check each cylinder bore for scuffing and scoring. Check for signs of a wear ridge at the top of the cylinder, indicating that the bore is excessively worn. 12 If the necessary measuring equipment is available, measure the bore diameter of each cylinder at the top (just under the wear ridge), centre, and bottom of the cylinder bore, parallel to the crankshaft axis (see
illustration).
13 Next, measure the bore diameter at the
same three locations, at right-angles to the crankshaft axis. As no tolerance figures are actually stated by Rover, if there is any doubt about the condition of the cylinder bores, seek the advice of a Rover dealer or suitable engine reconditioning specialist. 14 Having measured the cylinder bores, subtract the piston diameters measured previously to obtain the piston-to-bore clearance for each cylinder. If the clearances are outside the tolerance range then, assuming that the cylinder bores are satisfactory, it will be necessary to fit new pistons of the correct size. If this is the case, the bores should be honed, to allow the new rings to bed in correctly and provide the best possible seal. Honing is an operation that will be carried out for you by an engine reconditioning specialist.
15 If the cylinder bores are not in perfect condition, and providing they have not already been rebored to their maximum oversize limit, it should be possible to rectify any problems found by having the cylinder bores rebored and to fit matching oversize pistons. 16 After all machining operations are completed, the entire block/crankcase must be washed very thoroughly with warm soapy water to remove all traces of abrasive grit produced during the machining operations. When the cylinder block/crankcase is completely clean, rinse it thoroughly and dry it, then lightly oil all exposed machined surfaces, to prevent rusting.
14 Main and big-end bearings -
inspection and selection
3
Inspection
1 Even though the main and big-end bearing shells should be renewed during the engine overhaul, the old shells should be retained for close examination, as they may reveal valuable information about the condition of the engine. 2 Bearing failure occurs because of lack of lubrication, the presence of dirt or other foreign particles, overloading the engine, and corrosion (see illustration). Regardless of the cause of bearing failure, the cause must be corrected (where applicable) before the engine is reassembled, to prevent it from happening again. 3 When examining the bearing shells, remove them from the cylinder block/crankcase and main bearing caps, and from the connecting rods and the big-end bearing caps, then lay them out on a clean surface in the same general position as their location in the engine. This will enable you to match any bearing problems with the corresponding crankshaft journal. Do not touch any shell’s
2B•18 Engine removal and overhaul procedures
14.2 Typical bearing failures
13.7 Using a tap to restore cylinder block threads 13.12 Using a bore gauge to check for cylinder bore wear
bearing surface with your fingers while checking it, or the delicate surface may be scratched. 4 Dirt or other foreign matter gets into the engine in a variety of ways. It may be left in the engine during assembly, or it may pass through filters or the crankcase ventilation system. It may get into the oil, and from there into the bearings. Metal chips from machining operations and normal engine wear are often present. Abrasives are sometimes left in engine components after reconditioning, especially when parts are not thoroughly cleaned using the proper cleaning methods. Whatever the source, these foreign objects often end up embedded in the soft bearing material, and are easily recognised. Large particles will not embed in the material, and will score or gouge the shell and journal. The best prevention for this cause of bearing failure is to clean all parts thoroughly, and to keep everything spotlessly-clean during engine assembly. Frequent and regular engine oil and filter changes are also recommended. 5 Lack of lubrication (or lubrication breakdown) has a number of inter-related causes. Excessive heat (which thins the oil), overloading (which squeezes the oil from the bearing face) and oil leakage (from excessive bearing clearances, worn oil pump or high engine speeds) all contribute to lubrication breakdown. Blocked oil passages, which usually are the result of misaligned oil holes in a bearing shell, will also starve a bearing of oil, and destroy it. When lack of lubrication is the cause of bearing failure, the bearing material is wiped or extruded from the shell’s steel backing. Temperatures may increase to the point where the steel backing turns blue from overheating. 6 Driving habits can have a definite effect on bearing life. Full-throttle, low-speed operation (labouring the engine) puts very high loads on bearings, which tends to squeeze out the oil film. These loads cause the shells to flex, which produces fine cracks in the bearing face (fatigue failure). Eventually, the bearing material will loosen in pieces, and tear away from the steel backing. 7 Short-distance driving leads to corrosion of bearings, because insufficient engine heat is produced to drive off condensed water and corrosive gases. These products collect in the engine oil, forming acid and sludge. As the oil is carried to the engine bearings, the acid attacks and corrodes the bearing material. 8 Incorrect shell refitting during engine assembly will lead to bearing failure as well. Tight-fitting shells leave insufficient bearing running clearance, and will result in oil starvation. Dirt or foreign particles trapped behind a bearing shell result in high spots on the bearing, which lead to failure. 9 Do not touch any shell’s bearing surface with your fingers during reassembly; there is a risk of scratching the delicate surface, or of depositing particles of dirt on it.
Selection - main and big-end bearings
10 Main and big-end bearings for the majority of the engines described in this Chapter are available in one standard size and, on earlier engines, in a range of undersizes to suit reground crankshafts. 11 Selective standard size main bearings are fitted to later 998 cc and 1275 cc engines. Red (R), Green (G) or Yellow (Y) codes are used to identify the bearings, and the colours or “RGY” stamp will be found on the main bearing caps and the corresponding web of the crankshaft. The bearing shells are also identified in the same way. Undersize main and big-end bearings are no longer available from Rover dealers for these engines. 12 The relevant set of bearing shells required can be obtained by measuring the diameter of the crankshaft main bearing journals (see Section 12). This will show if the crankshaft is original or whether its journals have been reground, identifying if either standard or oversize bearing shells are required. 13 If access to the necessary measuring equipment cannot be gained, the size of the bearing shells can be identified by the markings stamped on the rear of each shell. Details of these markings should be supplied to your Rover dealer who will then be able to identify the size of shell fitted. 14 Whether the original shells or new shells are being fitted, it is recommended that the running clearance is checked as described in Section 17 prior to installation.
15 Engine overhaul - reassembly
sequence
1 Before reassembly begins, ensure that all new parts have been obtained, and that all necessary tools are available. Read through the entire procedure to familiarise yourself with the work involved, and to ensure that all items necessary for reassembly of the engine are at hand. 2 In order to save time and avoid problems, engine reassembly can be carried out in the following order:
a) Crankshaft (Section 17). b) Piston rings (Section 16) c) Piston/connecting rod assemblies
(Section 18). d) Oil pump (Section 10). e) Oil filter housing and delivery pipe (Part A
of this Chapter). f) Oil pressure relief valve (Part A of this
Chapter). g) Camshaft and tappets (Section 9). h) Cylinder head (Part A of this Chapter). i) Timing chain, sprockets and tensioner
(Part A of this Chapter). j) Distributor driveshaft (Part A of this
Chapter). k) Engine external components.
3 At this stage, all engine components should be absolutely clean and dry, with all faults repaired. The components should be laid out (or in individual containers) on a completely clean work surface.
16 Piston rings - refitting
2
1 Before fitting new piston rings, the ring end gaps must be checked as follows. 2 Lay out the piston/connecting rod assemblies and the new piston ring sets, so that the ring sets will be matched with the same piston and cylinder during the end gap measurement and subsequent engine reassembly. 3 Insert the top ring into the first cylinder, and push it down the bore using the top of the piston. This will ensure that the ring remains square with the cylinder walls. Position the ring near the bottom of the cylinder bore, at the lower limit of ring travel. On engines with tapered second and third compression rings, the top narrow side of the ring is marked with a “T”, or the word “TOP” (see illustration).
4 Measure the end gap using feeler blades. 5 Repeat the procedure with the ring at the
top of the cylinder bore, at the upper limit of its travel, and compare the measurements with the figures given in the Specifications. 6 If the gap is too small (unlikely if genuine Rover parts are used), it must be enlarged, or the ring ends may contact each other during engine operation, causing serious damage. Ideally, new piston rings providing the correct end gap should be fitted. As a last resort, the end gap can be increased by filing the ring ends very carefully with a fine file. Mount the file in a vice equipped with soft jaws, slip the ring over the file with the ends contacting the file face, and slowly move the ring to remove material from the ends. Take care, as piston rings are sharp, and are easily broken. 7 With new piston rings, it is unlikely that the end gap will be too large. If the gaps are too large, check that you have the correct rings for your engine and for the particular cylinder bore size.
Engine removal and overhaul procedures 2B•19
2B
16.3 Piston ring identification markings
8 Repeat the checking procedure for each
ring in the first cylinder, and then for the rings in the remaining cylinders. Remember to keep rings, pistons and cylinders matched up. 9 Once the ring end gaps have been checked and if necessary corrected, the rings can be fitted to the pistons. 10 Fit the piston rings using the same technique as for removal. Fit the bottom (oil control) ring first, and work up. When fitting a three piece oil control ring, first insert the expander and position its gap in line with the centre of the gudgeon pin. Fit the scraper rings with their gaps positioned either side of the expander gap. Where the oil control scraper is of one-piece type, position its gap 180° from the expander gap. Ensure that the second and third compression rings are fitted the correct way up, with their identification mark (either a “T” or the word “TOP” stamped on the ring surface) at the top (see illustrations). Carefully examine all rings for this mark before fitting. Arrange the gaps of the compression rings equally around the piston. Note: Always follow any instructions
supplied with the new piston ring sets ­different manufacturers may specify different procedures. Do not mix up the top and second compression rings, as they have different cross-sections.
17 Crankshaft - refitting and
running clearance check
3
1 Crankshaft refitting is the first stage of engine reassembly following overhaul. It is assumed at this point that the cylinder block/crankcase and crankshaft have been cleaned, inspected and repaired or reconditioned as necessary.
2 Position the cylinder block on a clean level work surface, with the crankcase facing upwards. Unbolt the bearing caps and carefully release them from the crankcase; lay them out in order to ensure correct reassembly. If they’re still in place, remove the old bearing shells from the caps and crankcase and wipe out the inner surfaces with a clean rag - they must be kept spotlessly clean. 3 Clean the backs of the bearing shells and insert them into position in the crankcase. If the original bearing shells are being used for the check, ensure that they are refitted in their original locations. Press the shells home so that the tangs engage in the recesses provided. When fitting the rear main bearing shell, it may be found that the cylinder block oilway is offset from the corresponding hole in the bearing shell. This condition is acceptable as long as a 2.3 mm diameter steel rod can be inserted into the exposed section of the hole. 4 Give the newly fitted bearing shells and the crankshaft journals a final clean with a rag. Check that the oil holes in the crankshaft are free from dirt, as any left here will become embedded in the new bearings when the engine is started. 5 Carefully lay the crankshaft in the crankcase taking care not to dislodge the bearing shells.
Running clearance check
6 When the crankshaft and bearings are fitted, a clearance must exist between them to allow lubricant to circulate. This clearance is impossible to check using feeler blades, so Plastigage is used. This consists of a fine thread of perfectly round plastic which is compressed between the bearing shell and the journal when the bearing caps are tightened up. When the cap and shell is
removed, the plastic is deformed and can be measured with a special card gauge supplied with the kit. The running clearance is determined from this gauge. The procedure for using Plastigage is as follows. 7 Cut off three lengths of Plastigage (they should be slightly shorter than the width of the main bearings) and place one length on each crankshaft journal axis (see illustration). 8 Wipe the inner surface of the bearing caps and the backs of the lower bearing shells and fit the three bearing shells to their caps. Press the shells home so that the tangs engage in the recesses provided. 9 Ensure that all six tubular locating dowels are firmly in place, one on each side of the upper halves of the three main bearings, and then fit the main bearing caps in position ensuring that they locate properly on the dowels. Tighten their retaining bolts to the specified torque. Take care not to disturb the Plastigage and do not rotate the crankshaft at any time during this operation. 10 Remove the main bearing caps again taking great care not to disturb the Plastigage or rotate the crankshaft.
2B•20 Engine removal and overhaul procedures
16.10a Piston ring identification - 850, 1000 and 1100 models
1 Chrome plated
compression ring 2 Taper compression ring 3 Taper compression ring
4 Top rail 5 Expander 6 Side spring 7 Bottom rail
16.10b Correct assembly of oil control ring - 1275 models
1 Bottom rail 2 Expander
3 Oil control ring rail 4 Top rail
17.7 Plastigage in place on main bearing journal
11 Compare the width of the crushed
Plastigage on each journal to the scale printed on the Plastigage envelope to obtain the main bearing running clearance (see illustration). Use the correct scale as both imperial and metric are printed. Compare the clearance measured with the running clearance dimension given in the Specifications. 12 If the clearance is significantly different from that expected, the bearing shells may be the wrong size (or excessively worn if the original shells are being re-used). Before deciding that the crankshaft is worn, make sure that no dirt or oil was trapped between the bearing shells and the caps or block when the clearance was measured. If the Plastigage was wider at one end than at the other, the crankshaft journal may be tapered. 13 Before condemning the components concerned, seek the advice of your Rover dealer or suitable engine repair specialist. They will also be able to inform as to the best course of action and whether it is possible to have the crankshaft journals reground or whether renewal will be necessary. 14 Where necessary, obtain the correct size of bearing shell and repeat the running clearance checking procedure as described above. 15 On completion, carefully scrape away all traces of the Plastigage material from the crankshaft and bearing shells using a fingernail or other object which is unlikely to score the bearing surfaces.
Crankshaft - final refitting
16 Lift the crankshaft out of the crankcase. Wipe the surfaces of the bearings in the crankcase and the bearing caps. 17 Wipe the recesses either side of the centre main bearings which locate the upper halves of the thrustwashers. 18 Generously lubricate the crankshaft journals and the upper and lower main bearing shells with clean engine oil and carefully place the crankshaft in position. 19 Introduce the upper halves of the thrustwashers (the halves without tabs) into their grooves on each side of the centre main bearing (see illustration), rotating the crankshaft in the direction towards the main bearing tabs (so that the main bearing shells do not slide out). At the same time feed the thrustwashers into their locations with their oil grooves facing outwards away from the bearing. 20 Ensure that all six tubular locating dowels are still firmly in place, one on each side of the upper halves of the three main bearings, and then fit the main bearing caps in position ensuring that they locate properly on the dowels. The mating surfaces must be spotlessly clean or the caps will not seat properly. 21 When refitting the centre main bearing cap, ensure that the thrustwashers, generously lubricated, are fitted with their oil grooves facing outwards, and the locating tab of each washer is in the slot in the bearing cap. 22 Refit the one-piece locking tabs over the main bearing caps (where applicable) and refit the main bearing cap bolts, screwing them up finger-tight initially, then finally tightening to the torque setting given in the Specifications
(see illustration). 23 Test the crankshaft for freedom of
rotation. Should it be very stiff to turn or possess high spots, re-check the running clearances as described above. 24 Carry out a check of the crankshaft endfloat as described in Section 12. If the thrust surfaces of the crankshaft have been checked and new thrustwashers have been fitted, then the endfloat should be within specification.
25 When all is satisfactory, secure the main bearing bolts by knocking up the locking tabs (where applicable) with a small chisel.
18 Piston/connecting rod
assemblies - refitting and big-
end bearing clearance check
3
Note: At this point it is assumed that the crankshaft has been refitted to the engine as described in Section 17.
Big-end bearing running clearance check
1 Clean the backs of the bearing shells, and the bearing locations in both the connecting rod and bearing cap. 2 Press the bearing shells into their locations, ensuring that the tab on each shell engages in the notch in the connecting rod and cap. If the original bearing shells are being used for the check, ensure that they are refitted in their original locations. 3 As with the main bearings (Section 17), a running clearance must exist between the big­end crankpin and its bearing shells to allow oil to circulate. There are two methods of checking the running clearance as described in the following paragraphs. 4 One method is to refit the big-end bearing cap to the connecting rod, with the bearing shells in place. With the cap retaining nuts or bolts correctly tightened, use an internal micrometer or vernier caliper to measure the internal diameter of each assembled pair of bearing shells. If the diameter of each corresponding crankshaft journal is measured and then subtracted from the bearing internal diameter, the result will be the big-end bearing running clearance. 5 The second, and more accurate method is to use Plastigage (see Section 17). 6 Ensure that the bearing shells are correctly fitted. Place a strand of Plastigage on each (cleaned) crankpin journal. 7 Temporarily refit the (clean) piston/ connecting rod assemblies to the crankshaft,
Engine removal and overhaul procedures 2B•21
2B
17.22 Tighten the main bearing cap bolts to the specified torque
17.11 Measuring the width of the deformed Plastigage using the card gauge supplied
17.19 Refitting the crankshaft thrustwasher upper halves
and refit the big-end bearing caps, using the marks made or noted on removal to ensure that they are fitted the correct way around. 8 Tighten the bearing cap nuts or bolts to the specified torque. Take care not to disturb the Plastigage, nor rotate the connecting rod during the tightening sequence. 9 Dismantle the assemblies without rotating the connecting rods. Use the scale printed on the Plastigage envelope to obtain the big-end bearing running clearance. Use the correct scale as both imperial and metric are printed. 10 If the clearance is significantly different from that given in the Specifications, the bearing shells may be the wrong size (or excessively worn, if the original shells are being re-used). Make sure that no dirt or oil was trapped between the bearing shells and the caps or block when the clearance was measured. If the Plastigage was wider at one end than at the other, the crankshaft journal may be tapered. 11 Before condemning the components concerned, refer to your Rover dealer or engine reconditioning specialist for their advice on the best course of action to be taken. 12 On completion, carefully scrape away all traces of the Plastigage material from the crankshaft and bearing shells. Use your fingernail, or some other object which is unlikely to score the bearing surfaces.
Piston/connecting rod assemblies - final refitting
13 Ensure that the bearing shells are correctly fitted as described earlier. Wipe dry the shells and connecting rods with a clean cloth. 14 Lubricate the cylinder bores, the pistons, and piston rings, then lay out each piston/connecting rod assembly in its respective position. 15 Start with assembly No 1. Make sure that
the piston rings are still spaced as described in Section 16, then clamp them in position with a piston ring compressor. 16 Insert the piston/connecting rod assembly into the top of cylinder No 1. Ensure that it is the correct piston/connecting rod assembly for that particular bore, that the connecting rod is the right way round, and that the front of the piston is towards the front of the engine. Using a block of wood or hammer handle against the piston crown, tap the assembly into the cylinder until the piston crown is flush with the top of the cylinder (see illustration). 17 Ensure that the bearing shell is still correctly installed. Liberally lubricate the crankpin and both bearing shells. Taking care not to mark the cylinder bores, pull the piston/connecting rod assembly down the bore and onto the crankpin. As the big-end bosses on the connecting rods are offset, it will be obvious if they have been inserted the wrong way round because they will not fit over the crankpin. The centre two rods must be fitted with their offset bosses facing away from the centre main bearing, and the connecting rods at each extremity of the engine must be fitted with their offset bosses
facing inwards (see illustration). Fit the big­end cap and retaining bolts with the one­piece locking tab under them (where applicable) and tighten the bolts to the specified torque. On 1275 cc engines the arrangement is slightly different, the caps being retained by nuts. 18 Once the bearing cap retaining nuts or bolts have been correctly tightened, rotate the crankshaft. Check that it turns freely; some stiffness is to be expected if new components have been fitted, but there should be no signs of binding or tight spots. 19 Refit the remaining three piston/ connecting rod assemblies in the same way.
19 Engine - initial start-up after
overhaul and reassembly
2
1 Refit the remainder of the engine components in the order listed in Section 15 of this Chapter, referring to Part A where necessary. Reconnect the engine to the transmission (Section 5 or 6 as applicable), then refit the power unit to the car as described in Section 3. 2 With the engine/transmission refitted, double-check the engine oil and coolant levels. Make a final check that everything has been reconnected, and that there are no tools or rags left in the engine compartment. 3 Remove the spark plugs. Disable the ignition system by disconnecting the ignition HT coil lead from the distributor cap, and earthing it on the cylinder block. Use a jumper lead or similar wire to make a good connection. 4 Turn the engine on the starter until the oil pressure warning light goes out. Refit the spark plugs, and reconnect the spark plug and distributor (HT) leads, referring to Chapter 1 for further information. 5 Start the engine, noting that this may take a little longer than usual, due to the fuel system components having been disturbed. 6 While the engine is idling, check for fuel, water and oil leaks. Don’t be alarmed if there are some odd smells and smoke from parts getting hot and burning off oil deposits. 7 Assuming all is well, keep the engine idling until hot water is felt circulating through the top hose, then switch off the engine. 8 Check the ignition timing and the idle speed settings (as appropriate), then switch the engine off. 9 After a few minutes, recheck the oil and coolant levels as described in Chapter 1, and top-up as necessary. 10 If new pistons, rings or crankshaft bearings have been fitted, the engine must be treated as new, and run-in for the first 500 miles (800 km). Do not operate the engine at full-throttle, or allow it to labour at low engine speeds in any gear. It is recommended that the oil and filter be changed at the end of this period.
2B•22 Engine removal and overhaul procedures
18.16 Refitting a piston with a piston ring clamp in position
18.17 The correct positions of the offsets on the connecting rod big-ends
3
Chapter 3
Cooling, heating and ventilation systems
General
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressurised, water pump assisted, thermo-syphon
Radiator filler/pressure cap setting:
Pre-1974 models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.91 bar
1974 models onward . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.05 bar
Thermostat
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wax
Opening temperatures:
Pre-1976 models:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82ºC
Hot climates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74ºC
Cold climates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88ºC
1976 models onward:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88ºC
Auxiliary cooling fan
Thermostatic switch settings:
Switches on at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98ºC
Switches off at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93ºC
Torque wrench settings Nm lbf ft
Water pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 to 25 14 to 18
Thermostat housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 to 12 6 to 9
Auxiliary cooling fan thermostatic switch - Cooper models . . . . . . . . . . 10 7
Antifreeze - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Auxiliary cooling fan - general information, removal and refitting . . . 7 Auxiliary cooling fan thermostatic switch - removal, testing and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Coolant level check . . . . . . . . . . . . . . . . . . . . . . .See “Weekly Checks”
Cooling system - draining . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Cooling system - flushing . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Cooling system hoses - disconnection and renewal . . . . . . . . . . . . . 2
Fresh air vent assembly - removal and refitting . . . . . . . . . . . . . . . . 13
Heater assembly - dismantling and reassembly . . . . . . . . . . . . . . . . 12
Heater assembly - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 11
Heater water valve - removal and refitting . . . . . . . . . . . . . . . . . . . . . 10
Heater water valve control cable - removal and refitting . . . . . . . . . . 9
Radiator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Thermostat - removal, testing and refitting . . . . . . . . . . . . . . . . . . . . 5
3•1
Specifications
Contents
Easy, suitable for
novice with little experience
Fairly easy, suitable for beginner with some experience
Fairly difficult,
suitable for competent DIY mechanic
Difficult, suitable for experienced DIY mechanic
Very difficult,
suitable for expert DIY or professional
Degrees of difficulty
5
4
3
2
1
1 General information and
precautions
The cooling system is of the conventional pressurised, water pump-assisted thermo­syphon type comprising a radiator, water pump, thermostat and associated hoses. Radiator cooling is provided by a fan mounted on the water pump and driven by a V-belt from the crankshaft pulley. An auxiliary electric cooling fan is fitted to later 1275 cc engine models. It is located beneath the left-hand front wheel arch, and provides an additional source of cooling for the radiator in conjunction with the belt-driven fan on the water pump.
The cooling system functions by circulating cold coolant from the bottom of the radiator, up the lower radiator hose to the water pump where it is pumped around the water passages in the cylinder block.
The coolant then travels up into the cylinder head and circulates around the combustion chambers and valve seats. When the engine is at its correct operating temperature, the coolant travels out of the cylinder head, past the open thermostat, into the hose and so into the top tank of the radiator. The coolant travels down the radiator where it is rapidly cooled by the rush of cold air through the radiator core. As the radiator is mounted next to the wheel arch, the fan pushes cold air through the radiator matrix. The coolant, now cool, reaches the bottom of the radiator where the cycle is repeated.
When the engine is cold, the thermostat (which is simply a temperature sensitive valve), maintains the circulation of coolant in the engine by blocking the passage from the cylinder head to the radiator. The coolant is then forced to return to the cylinder block through the bypass hose. Only when the opening temperature of the thermostat has been reached, does the thermostat allow the coolant to return to the radiator.
A basic heating and ventilation system is fitted which supplies warm or cold air to either the windscreen or car interior. A two-speed blower fan is fitted to supplement the airflow as required. Fresh air ventilation is provided by controllable air vents, located below the windscreen on each side of the car. These vents are independent of the main heater/blower unit and provide ambient air when the car is moving. The volume of air supplied is dependent on road speed.
Precautions
Warning: Do not attempt to remove the radiator filler cap, or to disturb any part of the cooling
system, while it or the engine is hot, as there is a very great risk of scalding. If the filler cap must be removed before the engine and radiator have fully cooled down (even though this is not recommended) the pressure in the cooling system must first be released. Cover the cap with a thick
layer of cloth, to avoid scalding, and slowly unscrew the filler cap until a hissing sound can be heard. When the hissing has stopped, showing that pressure is released, slowly unscrew the filler cap further until it can be removed; if more hissing sounds are heard, wait until they have stopped before unscrewing the cap completely. At all times, keep well away from the filler opening.
Warning: Do not allow antifreeze to come in contact with your skin, or with the painted
surfaces of the vehicle. Rinse off spills immediately with plenty of water. Never leave antifreeze lying around in an open container, or in a puddle in the driveway or on the garage floor. Children and pets are attracted by its sweet smell, but antifreeze is fatal if ingested.
2 Cooling system hoses -
disconnection and renewal
1
Note: Refer to the warnings given in Section 1 of this Chapter before proceeding. Hoses should only be disconnected once the engine has cooled sufficiently to avoid scalding.
1 If the checks described in Chapter 1 reveal a faulty hose, it must be renewed as follows. 2 First drain the cooling system (Chapter 1); if the antifreeze is not due for renewal, the drained coolant may be re-used, if it is collected in a clean container. 3 To disconnect the main system hoses, use a pair of pliers to release the spring clamps (or a screwdriver to slacken screw-type clamps), then move them along the hose clear of the union. Carefully work the hose off its stubs. The hoses can be removed with relative ease when new - on an older vehicle, they may have stuck. 4 If a hose proves to be difficult to remove, try to release it by rotating it on its unions before attempting to work it off. Gently prise the end of the hose with a blunt instrument (such as a flat-bladed screwdriver), but do not apply too much force, and take care not to damage the pipe stubs or hoses. Note in particular that the radiator hose unions are fragile; do not use excessive force when attempting to remove the hoses.
5 When refitting a hose, first slide the clamps onto the hose, then engage the hose with its unions. Work the hose into position, then check that the hose is settled correctly and is properly routed. Slide each clip along the hose until it is behind the union flared end, before tightening it securely.
6 Renewal of the by-pass hose (fitted between the top of the water pump and the underside of the cylinder head) is an awkward and tedious task which often presents problems. The easiest way to refit a bypass hose is to first place both clips in position on the hose. Fit the bottom of the hose to the water pump, bend the hose in half and then place the flat faces of a knife or feeler blade over the top of the hose and outlet in the cylinder head. Push the hose into an upright position and withdraw the blade. The hose should now be in position over the outlet. Several attempts may be necessary before the hose slides properly into position.
7 Refill the system with coolant (Chapter 1). 8 Check carefully for leaks as soon as
possible after disturbing any part of the cooling system.
3 Antifreeze - general
information
Note: Refer to the warnings given in Section 1 of this Chapter before proceeding.
1 The cooling system should be filled with a water/ethylene glycol-based antifreeze solution, of a strength which will prevent freezing down to at least -25ºC, or lower if the local climate requires it. Antifreeze also provides protection against corrosion, and increases the coolant boiling point. As with all mixed metal engines, the corrosion protection properties of the antifreeze are critical. Only a top quality antifreeze should be used in the system and should never be mixed with different antifreeze types. 2 The cooling system should be maintained according to the schedule described in Chapter 1. If antifreeze is used that is not to Rover’s specification, old or contaminated coolant mixtures are likely to cause damage, and encourage the formation of corrosion and scale in the system. 3 Before adding antifreeze, check all hoses and hose connections, because antifreeze tends to leak through very small openings. Engines don’t normally consume coolant, so if the level goes down, find the cause and correct it. 4 Ideally, at least a 30% mixture of antifreeze and clean soft water (by volume) should be used to maintain maximum protection against freezing and corrosion. Mix the required quantity in a clean container and then fill the system as described in Chapter 1, and “Weekly Checks”. Save any surplus mixture for topping-up.
3•2 Cooling, heating and ventilation systems
If all else fails, cut the hose with a sharp knife, then slit it so that it can be peeled off in
two pieces. Although this may prove expensive if the hose is otherwise undamaged, it is preferable to buying a new radiator.
If the hose is stiff, use a little soapy water as a lubricant, or soften the hose by
soaking it in hot water. Do not use oil or grease, which may attack the rubber.
4 Radiator - removal and
refitting
2
Note: Refer to the warnings given in Section 1 of this Chapter before proceeding.
Removal
1 Drain the cooling system as described in Chapter 1. 2 Refer to Chapter 11 and remove the bonnet. 3 Slacken the two retaining clips and completely remove the radiator top hose. 4 If the bottom hose was not removed for draining, slacken the retaining clip, using a long thin screwdriver, and pull the hose off the radiator outlet. 5 Undo and remove the bolts and nuts securing the radiator upper support bracket to
the fan cowling and thermostat housing. Lift away the bracket (see illustration). 6 On later 1275 cc engines (except carburettor engine Cooper models) disconnect the wiring connectors at the auxiliary cooling fan thermostatic switch in the bottom corner of the radiator. 7 At the base of the radiator undo and remove either the long through-bolt or the two short bolts (depending on model) that secure the lower support bracket to the engine mounting (see illustration). If necessary remove the front grille panel as described in Chapter 11 to provide greater access.
Cooling, heating and ventilation systems 3•3
3
4.5 Exploded view of radiator and attachments
1 Filler cap 2 Radiator 3 Drain tap adapter 4 Drain tap or plug 5 Rubber surround 6 Overflow pipe 7 Retaining clip 8 Cowl fixing screw 9 Nut 10 Cowl (one piece type) 11 Cowl (upper - two piece
type)
12 Cowl (lower - two-piece
type)
13 Bottom hose (non-
heater type)
14 Bottom hose (heater
type) 15 Hose clip 16 Upper mounting 17 Bolt 18 Washer 19 Rubber grommet 20 Lower mounting 21 Bolt 22 Washer 23 Rubber grommet 24 Washer 25 Bolt 26 Top hose
If leakage is the reason for wanting to remove the radiator, bear in mind that minor leaks can often be cured using a
radiator sealant with the radiator in situ.
8 Undo and remove the bolts securing the fan cowlings to the radiator, move the cowlings as far as possible toward the engine and carefully lift out the radiator. If a two piece cowling is fitted, lift off the top half.
Refitting
9 Refitting is the reverse sequence to removal. Apply a little rubber grease or liquid detergent to the inside diameter of the hoses, to allow them to be refitted more easily. 10 With the radiator in position, refill the cooling system as described in Chapter 1, and refit the bonnet and (if removed) the front grille panel as described in Chapter 11.
5 Thermostat - removal, testing
and refitting
2
Note: Refer to the warnings given in Section 1 of this Chapter before proceeding.
Removal
1 Partially drain the cooling system (approximately 1 litre) as described in Chap­ter 1. 2 Undo the retaining bolts securing the upper radiator mounting bracket to the radiator cowl. 3 Undo the two nuts or bolts securing the upper radiator mounting bracket to the thermostat cover, or the single nut securing the bracket to the thermostat housing body
(see illustrations). Remove the bracket. 4 Slacken the radiator top hose retaining clip
and disconnect the hose from the thermostat cover. Where applicable, disconnect the heater hose from the thermostat housing body and the wiring from the thermostatic switch or vacuum hoses from the thermostatic valve in the side of the housing body. Note the correct fitted positions of the vacuum hoses before disconnection. 5 Undo the remaining nut, or the three bolts (according to type) securing the thermostat cover, and lift off the cover and gasket. Where the cover is retained by nuts and studs, it is likely to be quite tight due to corrosion of the retaining studs. If so, apply liberal amounts of penetrating oil to the studs and allow time to
soak. Now very gently tap the cover from side to side, using a soft-faced mallet or block of wood. This should ease the corrosion and allow the cover to be lifted off. 6 With the cover removed, take out the thermostat. 7 On models with a separate thermostat housing body beneath the cover, lift off the housing body together with its lower gasket.
Testing
8 To test the thermostat for correct functioning, suspend it on a string in a saucepan of cold water together with a
thermometer (see illustration). Heat the water and note the temperature at which the thermostat begins to open. The correct opening temperatures are given in the Specifications at the beginning of this Chapter. Continue heating the water until the thermostat is fully open. Then let it cool down naturally. 9 If the thermostat does not fully open in boiling water, or does not close down as the water cools, then it must be discarded and a new one fitted. Should the thermostat be stuck open when cold, this will be apparent during removal.
Refitting
10 Refitting is the reverse sequence to removal bearing in mind the following points:
a) Clean off all traces of old gasket from the
component mating faces and renew any parts which show signs of corrosion.
b) Where the thermostat is located directly in
the cylinder head, use a new gasket between the cylinder head and thermostat cover. On models with a separate thermostat housing body, use new gaskets on both sides of the housing body.
c) Refill the cooling system as described in
Chapter 1 on completion.
6 Water pump - removal and
refitting
3
Note: Water pump failure is indicated by water leaking from the gland or front of the pump, or by rough and noisy operation. This is usually accompanied by excessive play of the pump spindle which can be checked by moving the fan blades from side to side. Water pumps are relatively inexpensive items and the simplest course of action, should the above symptoms be evident, is to fit an exchange reconditioned unit. Refer to the warnings given in Section 1 of this Chapter before proceeding.
Removal
Note: If the car is fitted with exhaust emission control equipment, it will be necessary to remove the air pump and drivebelt, as described in Chapter 4C, to provide access to the water pump.
3•4 Cooling, heating and ventilation systems
4.7 Radiator lower support mounting bolt accessible through grille panel
5.3a Exploded view of the thermostat and housing components (early models)
5.3b Thermostat housing and radiator upper mounting bracket
(later 1275 cc models)
5.8 Testing the thermostat
1 Remove the radiator (Section 4). 2 Remove the fan belt as described in
Chapter 1, then undo and remove the two nuts, bolts and washers securing the dynamo or alternator to the mounting bracket and water pump flange. Move the dynamo or alternator away from the engine, pivoting it on the adjusting arm bolt, and allow the unit to rest against the body front panel. 3 Undo and remove the bolts securing the fan and fan pulley to the water pump hub. Lift off the fan and pulley, and where fitted recover the spacer. As a guide to reassembly, make a mark to indicate the outer face of the fan as it is quite easy to refit this component the wrong way round. 4 Slacken the hose clips and detach the radiator bottom hose from the water pump outlet and also from the heater take-off connection, where applicable. Now slacken the clip that secures the bypass hose to the outlet on the top of the pump. 5 Undo and remove the four bolts securing the water pump to the cylinder block. Lift off the pump, and at the same time detach the bypass hose. Recover the water pump gasket
(see illustration). 6 Before refitting the pump, clean off all
traces of old gasket from the water pump and cylinder block mating faces, ensuring that the faces are smooth, clean and dry.
Refitting
7 Refitting the water pump is the reverse sequence to removal, bearing in mind the following points:
a) Always use a new gasket, which should
be lightly smeared on both sides with jointing compound.
b) The bypass hose should be renewed as a
matter of course, because these hoses sometimes prove unreliable and are extremely difficult to renew when the water pump is installed.
c) Refit and adjust the fan belt as described
in Chapter 1.
d) Refit the radiator as described in Section 4.
7 Auxiliary cooling fan -
general information, removal and refitting
2
General information
1 An auxiliary electric cooling fan is fitted to all later 1275 cc engine models. It is located beneath the left-hand front wheel arch, and provides an additional source of cooling for the radiator in conjunction with the belt-driven fan on the water pump. 2 The auxiliary cooling fan is switched on and off by a thermostatic switch. On carburettor engine Cooper models, the switch is screwed into the thermostat housing body on the cylinder head, whereas on all other models it is situated in the front bottom corner of the radiator.
Removal - carburettor engine Cooper models
3 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). Remove the left-hand front roadwheel. 4 Disconnect the air duct from the adapter beneath the front left-hand headlight. 5 Trace the fan motor wiring back to its connector, and disconnect it from the main wiring harness. 6 Slacken and remove the four cooling fan assembly shroud mounting nuts, and remove the assembly from underneath the wheel arch. Recover the mounting brackets, rubbers and spacers.
Removal - all except carburettor engine Cooper models
7 Remove the front grille as described in Chapter 11. 8 Undo the three mounting bolts and remove the radiator upper mounting bracket. Loosen the lower radiator mounting bolt.
9 Disconnect the fan motor wiring connector, which is situated by the side of the radiator filler cap (see illustration), and release the wiring grommet from the wing valance. 10 Slacken and remove the three (one lower and two upper) mounting nuts securing the fan shroud to the wing valance, then carefully withdraw the cooling fan assembly from underneath the wheel arch (see illustration). Recover any relevant mounting rubbers and spacers.
Refitting - all models
11 Refitting is the reverse sequence to removal, noting that the mounting rubbers should be renewed if they show any signs of wear or deterioration. Ensure that all disturbed nuts and bolts are securely tightened.
8 Auxiliary cooling fan
thermostatic switch -
removal, testing and refitting
2
Note: Refer to the warnings given in Section 1 of this Chapter before proceeding.
Removal
1 When the engine and radiator are cold, either drain the cooling system as described
Cooling, heating and ventilation systems 3•5
3
7.10 Removing the lower fan mounting nut (arrowed) - fuel injection models
6.5 Removing the water pump (shown with engine removed) 7.9 Auxiliary fan motor wiring connector (arrowed) ­fuel injection models
in Chapter 1, or carefully unscrew the radiator filler cap to release any remaining pressure, and have ready a suitable plug that can be used temporarily to stop the escape of coolant while the switch is removed. If the latter method is used, take care not to damage the threads, and do not use anything which will leave foreign matter inside the cooling system. 2 On carburettor engine Cooper models, disconnect the wiring connectors, then unscrew the switch from the thermostat housing. 3 On all other models, if necessary remove the front grille as described in Chapter 11 to improve access to the switch. Disconnect the two wiring connectors, then rotate the locking ring anti-clockwise to release it; withdraw the switch and rubber sealing ring from the bottom corner of the radiator (see illustration). Examine the sealing ring for signs of damage or deterioration, and renew if necessary.
Testing
4 To carry out a thorough test of the switch,
use two spare wires to connect it either to a multimeter (set to the resistance function) or to a battery-and-bulb test circuit. Suspend the switch in a pan of water which is being heated. Measure the temperature of the water with a thermometer. Do not let either the switch or the thermometer touch the pan itself. 5 The switch contacts should close to the “on” position (ie, continuity should exist) when the water reaches the specified switch-on temperature given in the Specifications at the start of this Chapter. Stop heating the water, and allow it to cool down; the switch contacts should open at the specified switch-off temperature. 6 If the switch performance is significantly different from that specified, or if it does not work at all, it must be renewed.
Refitting
7 On carburettor engine Cooper models,
ensure that the threads of the switch are clean, then apply a smear of suitable sealant to them. Refit the switch to the thermostat housing, tightening it to the specified torque, and reconnect the wiring connectors. 8 On all other models, fit the sealing ring to the switch, then refit the switch to the radiator and secure it in position with the locking ring.
Reconnect the wiring connectors, and refit the front grille (where removed). 9 On completion, either top-up or refill the cooling system as described in “Weekly Checks” or Chapter 1.
9 Heater water valve control
cable - removal and refitting
2
Removal
1 Disconnect the battery negative lead. 2 On pre-1989 models, slacken the inner
cable trunnion screw and the outer cable clamp screw at the heater water valve on the cylinder head. Release the cable from the valve. On 1989 models onward, release the outer cable retaining clip from the heater water valve on the engine compartment bulkhead. Disconnect the inner cable from the valve lever. Release the cable from its support clips. 3 From inside the car, undo and remove the screws, securing the centre console (where fitted). This will enable the console to be moved slightly as necessary to provide access to the control cable and heater. 4 Slacken the nut securing the rear of the heater unit to its mounting bracket. 5 Undo and remove the two screws securing the heater unit to the parcel shelf and lower the heater. 6 Detach the heater switch wire from the rear of the switch. 7 Undo and remove the two nuts securing the switch panel to the bracket under the parcel shelf. 8 Pull the switch panel forward slightly, undo the control cable retaining nut, and pull the complete cable through into the car. Recover the nut and washer from the end of the cable as it is pulled through.
Refitting
9 Refitting the cable is the reverse sequence to removal.
10 Heater water valve - removal
and refitting
2
Note: Refer to the warnings given in Section 1 of this Chapter before proceeding.
Removal
Pre-1989 models
1 Drain the cooling system as described in
Chapter 1. 2 Slacken the clip and disconnect the heater hose from the valve. 3 Slacken the inner cable trunnion screw and the outer cable clamp screw at the water valve, and release the control cable from the valve. 4 Undo the two nuts and remove the valve from the cylinder head studs.
1989 models onwards
5 Drain the cooling system as described in
Chapter 1. 6 Slacken the clips and disconnect the heater hoses from both sides of the valve (see
illustration). 7 Release the outer cable retaining clip and
disconnect the control cable from the valve lever. 8 Remove the valve assembly from the bulkhead.
Refitting
9 Refitting is the reverse sequence to removal, but check that the valve can be moved through its full range of travel. If necessary, adjust by repositioning the control outer cable in its clamp or retaining clip.
3•6 Cooling, heating and ventilation systems
8.3 Auxiliary cooling fan switch location (arrowed) - fuel injection models
10.6 Heater valve - 1989-on models
1 Outer cable retaining clip 2 Inner cable attachment 3 Coolant hose clip 4 Coolant hose clip
11 Heater assembly - removal
and refitting
2
Note: Refer to the warnings given in Section 1 of this Chapter before proceeding.
Recirculating type (early models)
Removal
1 Disconnect the battery negative lead. 2 Refer to Chapter 1 and drain the cooling
system. 3 Make a note of their relative positions, then disconnect the heater motor electric leads at the terminal connectors.
4 Slacken the demister and water hose clips. 5 To prevent water damage to the carpets or
upholstery, place polythene sheeting in the appropriate places on the floor and seating. 6 Undo and remove the screws that secure the heater unit to the parcel shelf and carefully lift away the heater unit.
Refitting
7 Refitting is the reverse of removal, but the
following additional points should be noted:
a) Open the heater tap on the rear of the
engine and slowly refill the cooling system as described in Chapter 1.
b) If the heater does not warm up, it is an
indication that there is an air lock. To clear, disconnect the return hose from the lower radiator hose and plug the hole. Now extend the return hose to reach the radiator filler neck. Start the engine and observe the flow of water from the return hose. When the bubbles cease, switch off the engine and reconnect the hose.
Fresh air type (later models)
Removal
8 Disconnect the battery negative lead. 9 Refer to Chapter 1 and drain the cooling
system. 10 On models with a centre console, remove the console and the facia glovebox securing screws. This will enable the console to be moved as necessary for greater access to the heater.
11 To prevent water damage to the carpets or upholstery, place polythene sheeting in the appropriate places on the floor and seating. 12 Carefully pull the demister and air inlet tubes out of the heater unit. 13 Undo and remove the two screws that secure the front of the heater to the parcel shelf. 14 Slacken the nut that secures the rear of the heater to the body mounted bracket (see
illustration). 15 Make a note of the electrical connections
to the blower motor and switch, then disconnect the wires. 16 Slacken the clips and disconnect the heater water hoses. 17 Carefully lift the heater unit from the slotted rear brackets, hold the fingers over the matrix pipe ends (or plug with corks) and lift the unit from the car. 18 Finally drain any remaining coolant from the unit.
Refitting
19 Refitting the heater assembly is the
reverse sequence to removal. Refill the cooling system as described in Chapter 1 on completion.
12 Heater assembly -
dismantling and reassembly
3
Recirculating type
Dismantling
1 Remove the heater assembly from the car
as described in Section 11. 2 Detach the spring clips securing the demister flap to the cover plate and lift off the flap (see illustration). 3 Undo and remove the screws securing the cover plate to the cowling and lift off the cover plate and motor assembly.
Cooling, heating and ventilation systems 3•7
3
11.14 Fresh air heater attachment points
A Securing screws - heater to parcel shelf B Nut and spring washer - heater to rear
bracket
12.2 Exploded view of the recirculatory heater
1 Hose 2 Clip 3 Connection 4 Outlet hose 5 Inlet hose 6 Tap 7 Gasket 8 Mounting
bracket 9 Nut 10 Washer 11 Washer
12 Sealing plate 13 Cowling 14 Demister hose 15 Fan 16 Screw 17 Washer 18 Motor
mounting 19 Motor 20 Spring 21 Connector 22 Sleeve
23 Flap 24 Screw 25 Nut 26 Washer 27 Fan retaining
screw
28 Screw
4 Prise the fan off the motor spindle, undo and remove the retaining nut and washer, then lift away the motor. 5 Undo and remove the screws securing the mounting bracket to the cowling, lift off the mounting bracket and withdraw the heater matrix. 6 Clean off all traces of rust and dirt from the matrix, and carefully inspect it for leaks or signs of excessive corrosion. The matrix should be renewed if it is badly corroded or leaking.
Reassembly
7 Reassembly is the reverse of the
dismantling procedure.
Fresh air type (first version)
Dismantling
8 Remove the heater assembly from the car
as described in Section 11. 9 Undo and remove the two screws securing the control panel to the heater casing and lift off the panel (see illustration). 10 Carefully prise off the spring retaining clips and separate the two halves of the casing. 11 Withdraw the motor assembly and then lift out the heater matrix.
12 The two rotors may be removed from the blower motor by releasing the retaining clips and sliding off the rotors. 13 Clean off all traces of rust and dirt from the matrix, and carefully inspect it for leaks or signs of excessive corrosion. The matrix should be renewed if it is badly corroded leaking.
Reassembly
14 Reassembly is the reverse of the
dismantling procedure.
Fresh air type (second version)
Dismantling
15 Remove the heater assembly from the car
as described in Section 11. 16 Detach the wire from the fan motor at the rear of the fan switch. 17 Undo and remove the three screws and lift off the heater control mounting plate. 18 Undo and remove the nine screws securing the right-hand end cover and lift off the cover.
19 Carefully slide out the heater matrix. 20 Undo and remove the screws securing the
fan motor to the main casing, release the motor wires and grommet, and withdraw the motor assembly.
21 If necessary, remove the two fans from the motor spindle. 22 Clean off all traces of rust and dirt from the matrix, and carefully inspect it for leaks or signs of excessive corrosion. The matrix should be renewed if it is badly corroded or leaking. Note that on later models, the diameter and length of the heater inlet hose has been increased. If the heater matrix is to be renewed, it is important that the longer (1005.0 mm) hose is also fitted.
Reassembly
23 Reassembly is the reverse of the
dismantling procedure.
Fresh air type (third version ­1985 models onward)
Dismantling
24 Remove the heater assembly from the car
as described in Section 11. 25 To remove the heater matrix, undo the two screws securing the matrix endplate, and withdraw the endplate, complete with matrix, from the heater casing. 26 Undo two screws each, and lift the pipe stubs off the matrix endplate (see illustration).
3•8 Cooling, heating and ventilation systems
12.9 Exploded view of the early type fresh air heater
1 Control panel 2 Fan switch 3 Control panel
securing screws
4 Washer 5 Heater casing 6 Heater casing
7 Retaining clip 8 Matrix 9 Air distribution flap
10 Trunnion screw 11 Fan motor 12 Air intake fan
13 Retaining clips 14 Recirculating fan 15 Flap valve
16 Valve securing
plate
17 Valve securing
screws
27 Clean off the matrix, and carefully inspect it for leakage or corrosion. If it is leaking, renewal is recommended, as repairs are seldom successful unless done professionally. 28 Inspect the condition of the O-rings on the pipe stubs, and renew if necessary. 29 To remove the heater motor and fan, disconnect the motor switch wiring, undo the three screws, and withdraw the motor and fan from the casing (see illustration). 30 Further dismantling of the motor and fan assembly is not possible, and if renewal is necessary, a complete assembly will be required.
Reassembly
31 Reassembly is the reversal of the
dismantling procedure.
13 Fresh air vent assembly -
removal and refitting
1
Removal
1 Unscrew the fresh air vent retaining collar and lift away the binnacle (see illustrations). 2 Turn the air vent anti-clockwise and remove it (see illustration).
Refitting
3 Refitting is the reverse sequence to removal.
Cooling, heating and ventilation systems 3•9
3
13.1a Unscrew the fresh air vent retaining collar . . .
13.1b . . . and lift away the binnacle 13.2 Turn the air vent anti-clockwise to remove
12.26 Later-type heater matrix
1 Matrix endplate 2 Endplate retaining
screws
3 Pipe stub retaining screw 4 Pipe stub 5 O-ring
12.29 Later-type heater motor
1 Retaining screws 2 Heater motor
3 Switch wiring connector
4A
Chapter 4 Part A:
Fuel system - carburettor engines
General
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rear-mounted fuel tank, electric or mechanical fuel pump, single or
twin SU variable choke carburettor
Carburettor data
Mini 850 Saloon and variants, 848 cc, (85H) 1969-72 1972-74 1974-76 1976 on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS2 SU HS2 SU HS4 SU HS4
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red Red Red Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm 2.3 mm 2.3 mm 2.3 mm
Needle:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EB AAV ABS ADH
Rich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M - - -
Weak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GG - - -
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 3.5 to 4.5 3.5 to 4.5 3.0 to 4.5
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500 rpm 800 rpm 800 rpm 750 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900 rpm 1200 rpm 1200 rpm 1200 rpm
Mini Clubman and Mini 1000 Saloon and variants, manual transmission, 998 cc, (99H), up to 1974
1969-72 1972-74
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS2 SU HS2
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm 2.3 mm
Needle:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GX AAV
Rich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M -
Weak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GG -
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 3.5 to 4.5
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500 rpm 800 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900 rpm 1200 rpm
Air cleaner assembly - removal and refitting . . . . . . . . . . . . . . . . . . . 2
Anti-run-on valve (1990-on Cooper models) - removal and refitting . 17
Carburettor (SU HIF44 and HIF38)) - fault diagnosis and overhaul . . 14 Carburettor (SU HIF44 and HIF38) - idle speed and mixture
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Carburettor (SU HS2 and HS4) - fault diagnosis and overhaul . . . . . 13
Carburettor (SU HS2 and HS4) - idle speed and mixture adjustment 15
Electric fuel pump - testing, removal and refitting . . . . . . . . . . . . . . . 6
Fuel gauge sender unit - removal and refitting . . . . . . . . . . . . . . . . . 8
Fuel system components, checks and lubrication . . . . .See Chapter 1
Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Mechanical fuel pump - testing, removal and refitting . . . . . . . . . . . 7
Underbody and fuel/brake line check . . . . . . . . . . . . . . .See Chapter 1
Underbonnet check for fluid leaks and hose condition . .See Chapter 1
Unleaded petrol - general information and usage . . . . . . . . . . . . . . . 10
4A•1
Specifications
Contents
Easy, suitable for
novice with little experience
Fairly easy, suitable for beginner with some experience
Fairly difficult,
suitable for competent DIY mechanic
Difficult, suitable for experienced DIY mechanic
Very difficult,
suitable for expert DIY or professional
Degrees of difficulty
5
4
3
2
1
Mini Clubman and Mini 1000 Saloon, automatic transmission, 998 cc, (99H), up to 1974
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS4
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm
Needle:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC
Rich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ml
Weak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HA
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1050 rpm
Mini Clubman and Mini 1000 Saloon and variants, manual and automatic transmission, 998 cc, (99H), 1974-83
1974-76 1976-78 1978-83
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS4 SU HS4 SU HS4
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red Red Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm 2.3 mm 2.3 mm
Needle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ABX ADE ADE
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 to 4.5 3.0 to 4.5 3.0
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 rpm 750 rpm 750 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1200 rpm 1250 rpm 1250 rpm
Mini Saloon and variants, manual and automatic transmission, 998 cc (99H), 1983-89
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS4
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm
Needle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AAC
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 ± 1.0
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 ± 50 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1100 ± 50 rpm
Mini Saloon and variants, manual and automatic transmission, 998 cc (99H), 1989-on
(low compression) (high compression)
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS4 SU HS4
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm 2.3 mm
Needle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADE AAC
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 ± 1.0 2.5 ± 1.0
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 ± 50 rpm 750 ± 50 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1100 ± 50 rpm 1100 ± 50 rpm
Mini Clubman 1100, 1098 cc, (10H) 1974 on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS4
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm
Needle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ABP
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 to 4.5
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1150 to 1300 rpm
Mini Cooper S Mk III, 1275 cc, (12H) 1969 on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Twin SU HS2
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm
Needle:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M
Rich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AH2
Weak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EB
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 rpm
Mini 1275 GT, 1275 cc, (12H) 1969-72 1972-76 1976-77 1978 on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HS4 SU HS4 SU HS4 SU HS4
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red Red Red Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 mm 2.3 mm 2.3 mm 2.3 mm
Needle:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC AAV ABB AAT
Rich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BQ - - -
Weak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HA - - -
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 3.5 to 4.5 3.0 to 4.5 3.0 to 4.0
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650 rpm 800 rpm 850 rpm 750 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1050 rpm 1200 rpm 1300 rpm 1300 rpm
4A•2 Fuel system - carburettor engines
Mini Cooper, 1275 cc, (12A) 1990-on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HIF44
Piston spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Red
Jet size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 mm
Needle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BFY
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 to 3.0 (measured at gas sampling pipe)
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900 rpm
Fast idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1200 ± 50 rpm
Mini Saloon and variants, 1275 cc (12A) 1992-on
Carburettor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SU HIF38
At the time of writing, no further specifications were available for this model.
Recommended fuel
Minimum octane rating (see text Section 10):
All pre-1989 models* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 RON leaded
1989-on, 998 cc low-compression models . . . . . . . . . . . . . . . . . . . . 95 RON unleaded or 90 RON leaded
1989-on, 998 cc high-compression models . . . . . . . . . . . . . . . . . . . . 95 RON unleaded or 97 RON leaded
1990-on 1275 cc (12A) models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 RON unleaded only
*Pre-1989 models with a “Green pack” can be run on 95 RON unleaded petrol - see text for further information.
Note: Models with a catalytic converter must be run on unleaded petrol only.
Torque wrench setting Nm lbf ft
Manifold retaining nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 16
1 General information and
precautions
General information
The fuel system comprises a fuel tank, an electric or mechanical fuel pump and a variable choke carburettor.
The fuel tank is located in the luggage compartment on Saloon models, and beneath the rear floor on the Estate, Van and Pick-up variants. On Cooper S versions twin fuel tanks are used, these being positioned on either side of the luggage compartment.
A number of the earlier vehicles covered by this manual are equipped with an SU electric fuel pump which is mounted on the left-hand member of the rear subframe. All later Mini models utilise a mechanical fuel pump bolted to the rear of the engine and operated by an eccentric on the camshaft.
A variable choke carburettor of SU manufacture is fitted to all models. Manual transmission versions manufactured up to 1974 utilise a single SU HS2 unit, the exception to this being the Cooper S model which incorporates a twin carburettor installation. Later vehicles are equipped with the larger SU HS4 carburettor, or its derivatives the HIF38 and HIF44. Further information on carburettor types will be found later in this Chapter.
Certain models are fitted with emission control equipment to reduce the level of harmful emissions in the exhaust gases. Information on the exhaust and emission control systems is contained in Part C of this Chapter.
Precautions
Warning: Petrol is extremely flammable - great care must be taken when working on any part
of the fuel system. Do not smoke or allow any naked flames or uncovered light bulbs near the work area. Note that gas powered domestic appliances with pilot flames, such as heaters, boilers and tumble dryers, also present a fire hazard ­bear this in mind if you are working in an area where such appliances are present. Always keep a suitable fire extinguisher close to the work area and familiarise yourself with its operation before starting work. Wear eye protection when working on fuel systems and wash off any fuel spilt on bare skin immediately with soap and water. Note that fuel vapour is just as dangerous as liquid fuel; a vessel that has just been emptied of liquid fuel will still contain vapour and can be potentially explosive. Petrol is a highly dangerous and volatile liquid, and the precautions necessary when handling it cannot be overstressed.
Many of the operations
described in this Chapter involve
the disconnection of fuel lines,
which may cause an amount of fuel spillage. Before commencing work, refer to the above Warning and the information in “Safety first” at the beginning of this manual.
When working with fuel system
components, pay particular
attention to cleanliness - dirt
entering the fuel system may cause blockages which will lead to poor running.
2 Air cleaner assembly -
removal and refitting
1
All models except Cooper, and 1992-on models with open-loop catalytic converter
Removal
1 Undo and remove the single wing nut and
washer on early models, or the twin wing bolts and washers on later models, securing the air cleaner to the carburettor (see illustrations). 2 If the air cleaner is retained by a single wing nut lift off the air cleaner top cover. Detach the rocker cover hose, then lift the air cleaner body off the carburettor, tip it up at the front and slide it sideways until it is clear of the long retaining stud and can be lifted away. Recover the sealing ring (see illustrations).
Fuel system - carburettor engines 4A•3
4A
2.1a Remove the single wing nut on early models . .
3 If the air cleaner is retained by two wing
bolts, detach the hot air duct (where fitted) and then lift the air cleaner body off the carburettor (see illustrations). 4 With the air cleaner removed from the engine, recover the rubber sealing ring if it stayed behind on the carburettor flange.
Refitting
5 Refitting the air cleaner is the reverse
sequence to removal. Ensure also that the rubber sealing ring is in position before refitting the air cleaner. 6 If the air cleaner body incorporates an
adjustable air inlet spout, this should be positioned adjacent to the exhaust manifold in winter and away from it in summer.
Cooper S Mk III models
Removal
7 Undo and remove the two wing bolts and
washers then disconnect the engine breather pipe and the throttle return spring. Lift off the air cleaner body and recover the two rubber sealing rings from the carburettor flanges.
Refitting
8 Refitting is the reverse sequence to removal
but ensure that the rubber sealing rings are in position on the carburettor’s flanges.
1990-on Cooper models
Removal
9 Unscrew the two nuts securing the air inlet
duct to the rocker cover studs, then release the clip and disconnect the duct from the air cleaner (see illustration). 10 Unscrew and remove the nuts and washers, then lift the air cleaner from the carburettor and disconnect the hot air hose. Remove the sealing ring from the carburettor flange.
Refitting
11 Refitting is the reverse sequence to
removal but ensure that the rubber sealing ring is in position on the carburettors flange.
1992-on models with open-loop catalytic converter
Removal
12 Unscrew the two wing nuts, and lift the air
cleaner assembly away from the carburettor. Recover the sealing ring from the carburettor flange.
Refitting
13 Refitting is the reverse sequence to
removal but ensure that the rubber sealing ring is in position on the carburettors flange.
4A•4 Fuel system - carburettor engines
2.2b Recover the sealing ring
2.3a If the air cleaner is retained by two wing bolts detach the hot air duct . . .
2.3b . . . and lift off the air cleaner body . . .
2.1b . . . or the two wing bolts on later models 2.2a If the air cleaner is retained by a single wing nut, lift off the top cover and withdraw the air cleaner body from the carburettor
2.9 Air cleaner and intake duct fitted to 1990-on Cooper models
1 Intake duct retaining nuts 2 Intake duct 3 Air cleaner mounting nuts
3 Accelerator cable - removal
and refitting
1
Removal
1 Working in the engine compartment, disconnect the throttle return spring(s) and undo the nut and washer securing the cable to the bolt on the throttle lever (see illustration). On later models the cable is attached to the throttle lever by means of a small clamp with a locking bolt through its centre. Hold the clamp and unscrew the bolt using either 4 BA or 7 BA spanners according to clamp type. 2 Pull the cable through the bolt or clamp and slide it out of the steady bracket on the rocker cover (if fitted). 3 From inside the car, depress the accelerator pedal and withdraw the ferrule on the cable from the slot in the top of the pedal arm. 4 The cable can now be withdrawn through the opening in the bulkhead and into the engine compartment.
Refitting
5 To refit the cable, feed it through the
bulkhead and engage the ferrule into the slot on the pedal arm. 6 Now feed the other end of the cable through the brackets on the rocker cover and carburettor, and then insert the inner cable into the slotted bolt or clamp on the throttle lever. 7 Pull the cable through the bolt to take up any slack and then refit the washer and nut or the clamp locking bolt. Avoid straining or distorting the cable as the fixings are tightened. 8 Reconnect the return spring and check that a slight amount of free play exists between the pedal and cable. 9 Start the engine and check the operation of the cable.
4 Accelerator pedal - removal
and refitting
1
Removal
1 Depress the accelerator pedal and detach the accelerator cable ferrule from the slot at the top of the pedal arm. 2 Undo and remove the two bolts securing the pedal assembly to the bulkhead and lift out the pedal.
Refitting
3 Refitting is the reverse sequence to removal.
5 Choke cable - removal and
refitting
2
Removal
Note: On models fitted with a centre console it will be necessary to remove the centre console and console glovebox retaining screws. This will allow the console to be moved slightly to provide access for the following operations.
1 Disconnect the battery negative lead. 2 Refer to Section 2 and remove the air
cleaner assembly. 3 Working in the engine compartment, disconnect the choke inner cable from the trunnion screw on the choke linkage and the outer cable from the support bracket (see illustration). Withdraw the complete cable from the carburettor. 4 From inside the car, undo and remove the two screws securing the heater assembly to the front of the parcel shelf. Now lower the heater slightly at the front.
Fuel system - carburettor engines 4A•5
4A
3.1 Accelerator cable attachments
1 Throttle return spring 2 Cable-to-throttle lever
securing bolt
3 Cable support bracket 4 Cable ferrule – pedal end 5 Outer cable
1 Inner cable-to-linkage
attachment 2 Outer cable support bracket 3 Switch panel retaining nuts
4 Switch panel 5 Choke cable 6 Cable retaining nut and
washer
5.3 Choke cable attachments
5 Disconnect the heater switch wires from the
switch. 6 Undo and remove the two nuts or screws which secure the auxiliary switch panel to the centre of the parcel shelf. 7 Draw the switch panel forward and unscrew the choke cable retaining nut, or extract the retaining clip (according to type) from the rear of the panel. 8 Pull the complete cable through the bulkhead grommet and switch panel, into the passenger compartment. Recover the retaining nut and lockwasher from the end of the cable.
Refitting
9 To refit the cable, slide it through the slot in the switch panel and then place the nut and washer over the cable. 10 Insert the cable through the bulkhead grommet and through to the engine compartment. 11 Screw on and fully tighten the choke cable retaining nut or refit the clip then refit the switch panel. Position the word LOCK on the cable knob at the top to ensure correct operation in use. Reconnect the heater switch leads and refit the heater securing screws. 12 Engage the other end of the cable into the support bracket and the inner cable into the trunnion on the choke linkage. 13 Ensure that the choke cable is pushed fully in, ie in the “off” position, then tighten the retaining screws on the support bracket and cable trunnion. Ensure that there is 1.5 mm of free play on the cable before the cable starts to operate the choke linkage. 14 Refit the air cleaner, reconnect the battery and, where applicable, refit the centre console retaining screws.
6 Electric fuel pump - testing,
removal and refitting
2
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
Testing
1 To test the fuel pump, disconnect the fuel supply hose at the top of the carburettor float chamber and immerse the end of the hose in a clean glass jar. With the ignition switched on there should be a steady flow of petrol from the end of the hose accompanied by a regular ticking noise from the pump.
Warning: Carry out this operation in a well ventilated area and take great care not to splash fuel onto hot engine components.
2 A rapid irregular ticking noise accompanied by a mixture of fuel and air bubbles flowing from the hose is indicative of an air leak on the suction side of the pump (ie in the pipe between the pump and fuel tank). This will ultimately lead to fuel starvation and cutting out or misfiring if not corrected.
3 No fuel flow from the supply hose indicates a fault in the pump (perforated diaphragm, dirty contact points etc), or a break in the electrical supply to the pump. If the electrical supply to the pump is sound but the pump is still not functioning, it should be taken to an auto-electrician for inspection and possible repair, or replaced with an exchange unit. Repair kits are unlikely to still be available from normal sources so an exchange unit may be the only alternative.
Removal
4 Disconnect the battery negative lead. 5 Chock the front wheels then jack up the
rear of the car and support it on axle stands (see “Jacking and vehicle support”). 6 Working under the car, disconnect the earth lead and the electrical supply wire from their terminals on the pump body. 7 Prepare to squeeze the rubber portion of the petrol pipe leading from the tank with a self-gripping wrench or similar tool, to ensure that the minimum amount of fuel is lost when the inlet pipe is removed from the pump. Plug the end of the pipe with a bolt or metal rod of suitable diameter immediately it is disconnected. 8 Remove the inlet and outlet fuel pipes by undoing the retaining clip screws and easing the pipes off the pump nozzles (see illustration). Remove the vent pipe connector, if fitted, at this stage. 9 Undo and remove the two nuts, bolts and spring washers securing the pump bracket to the subframe and lift off the pump assembly, complete with bracket and clamp. 10 To separate the pump from the bracket, slacken the clamp bolt and slide the pump out of the clamp.
Refitting
11 Refitting is the reverse sequence to removal, bearing in mind the following points:
a) Arrows on the pump body indicate the
correct locations of the inlet and outlet pipes. Ensure that these are fitted correctly and that the pump is installed with the outlet pipe at the top.
b) Ensure that the electrical leads,
particularly the earth, are clean and that a correct connection is made.
7 Mechanical fuel pump -
testing, removal and refitting
2
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
Testing
1 To test the fuel pump, disconnect the fuel supply hose at the top of the carburettor float chamber and immerse the end of the hose in a clean glass jar. With an assistant cranking the engine on the starter, regular spurts of fuel should be ejected as the engine turns.
Warning: Carry out this operation in a well ventilated area and take great care not to splash fuel onto hot engine components.
2 If the pump does not operate satisfactorily, it should be renewed. The AUF 700 series pump fitted to early models may be dismantled for inspection, but repair kits are unlikely to still be available from normal sources. The AUF 800 series pump fitted to later models is a sealed unit and cannot be dismantled.
Removal
Note: The fuel pump used on later models (1985-on) is different in appearance to those used previously, but is fully interchangeable. A modified kickdown rod will be required if a new type pump is fitted to older vehicles with automatic transmission. Details of the rod fitment should be obtained from your dealer.
3 Disconnect the battery negative lead. 4 To provide greater access, remove the air
cleaner, as described in Section 2. 5 Slacken the pipe clip screw on the outlet pipe connection and draw it off. Have a small container handy to collect what little fuel may drain from the pipe. 6 In all Saloon models, if the tank is more than half full, the fuel will drain from the tank under gravity when the fuel pump inlet pipe is disconnected, so provide for this situation by fitting a suitable clip or bung in the pipe if necessary. On all other models the tank is below the pump level, so this problem will not occur. Slacken the pipe clip screw on the inlet pipe connection and draw it off. 7 Slacken the two nuts which hold the pump to the crankcase on two studs through the lower body. 8 Ease the pump away from the crankcase slightly and release the insulating block and its two sealing gaskets. If they are stuck, carefully prise them off the crankcase using a knife or thin screwdriver. Now lift off the pump, insulating block and gaskets.
Refitting
9 Refitting the pump is the reverse sequence to removal bearing in mind the following points:
a) Ensure that the mating faces of the pump
and crankcase are thoroughly clean and dry.
4A•6 Fuel system - carburettor engines
6.8 Removing the fuel outlet pipe from the electric pump
b) Ensure that the correct insulator block is
used according to pump type. The insulator block fitted to the 700 series pump is different from the insulator block fitted to 800 series and AZX series pumps (see illustration). The 700 series pump requires an insulator block with a large inner aperture, whereas the 800 series and AZX pumps require an insulator block with a small aperture in order to retain the pump lever pivot. If the wrong insulator block is fitted, there is a possibility of the pivot and lever dropping into the sump/transmission.
c) Use new sealing gaskets on either side of
the insulating block but make sure that the original thickness is maintained otherwise the pump operation may be affected.
8 Fuel gauge sender unit -
removal and refitting
2
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
Removal
Saloon models
1 Disconnect the battery negative lead and
remove the fuel gauge wires from their attachments to the sender unit mounted in the side of the tank (see illustration). 2 On early models, unscrew the screws which hold the gauge unit to the tank carefully, and lift the complete unit away, ensuring that the float lever is not bent or damaged in the process. 3 On later models, using crossed screwdrivers, remove the fuel gauge sender unit by turning the locking ring through 30º and lifting away. Carefully lift the unit from the
tank, ensuring that the float lever is not bent or damaged in the process.
Estate, Van and Pick-up models
4 Refer to Section 9 and remove the fuel tank
from the car. 5 Removal and refitting of the sender unit now follows the procedure described for Saloon models.
Refitting
6 Refitting the unit is the reverse sequence to removal. To ensure a fuel-tight joint, scrape both the tank and sender unit mating flanges clean, and always use a new joint gasket and a suitable gasket sealer.
9 Fuel tank - removal and
refitting
2
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
Saloon models except Cooper S
Removal
1 Before the tank can be removed, it must be
drained of as much fuel as possible. To avoid the dangers and complications of fuel handling and storage, it is advisable to carry out this operation with the tank almost empty. Any fuel remaining can be drained as follows.
2 Disconnect the battery negative lead. 3 Using a hand pump or syphon inserted
through the filler neck, remove any remaining fuel from the bottom of the tank. Note: A
number of earlier models were fitted with a fuel tank incorporating a combined drain plug and tube. Access to this is from below the car, using a long box spanner. In all cases carry
out the draining or siphoning operation in a well ventilated area, never in a garage or over an inspection pit.
4 Remove the spare wheel from its location in the luggage compartment. 5 Disconnect the wiring from the fuel gauge sender unit located on the side of the tank
(see illustration). 6 If the car is fitted with an electric fuel pump,
slacken the clip and detach the fuel inlet hose from the pump inlet nozzle. Collect any remaining fuel in a suitable container. 7 When the tank is empty, slacken the clip and detach the fuel hose from the front of the tank. 8 Detach the fuel tank breather pipe and remove the filler cap. 9 Undo and remove the tank securing strap bolt and carefully manoeuvre the fuel tank from the luggage compartment. 10 If the tank is contaminated with sediment or water, remove the fuel gauge sender unit as described in Section 8 and swill the tank out with clean fuel. If the tank is damaged or corroded it should be renewed. However, in certain cases it may be possible to have small leaks or minor damage repaired. Seek the advice of a Rover dealer or suitable specialist concerning tank repair.
Refitting
11 Refitting is the reverse sequence to
removal.
Estate, Van and Pick-up models
12 Disconnect the battery negative lead. 13 Chock the front wheels then jack up the
rear of the car and support it on axle stands (see “Jacking and vehicle support”). 14 Remove the tank filler cap then, from underneath the car, undo and remove the drain plug, allowing the fuel to drain into a suitable container. Do this in a well ventilated area, not in a garage or over an inspection pit. When drained, refit the drain plug and washer securely.
Fuel system - carburettor engines 4A•7
4A
7.9 Mechanical fuel pump insulator block types
A 700 series type B 800 and AZX series type
8.1 Electrical leads at the fuel gauge sender unit on the side of the tank (Saloon models)
15 Disconnect the fuel outlet pipe and the
fuel gauge wires from their connections on the sender unit on the side of the tank (see
illustration). 16 Undo and remove the six screws which
hold the tank in place and remove the tank. It is helpful if a jack is positioned under the tank as the retaining screws are removed so that the tank does not drop out under its own weight. It may also be found easier to lower the tank slightly on the jack before disconnecting the sender unit leads, as with the tank half removed they are more accessible. 17 Refer to the information contained in paragraph 10.
Refitting
18 Refitting the tank is the reverse sequence
to removal bearing in mind the following points:
a) Make sure that the nylon spacers located
at each retaining screw hole are in position before refitting the tank.
b) Ensure that the drain plug and washer are
in place and securely tightened.
c) Ensure that the rubber ferrule beneath the
filler cap makes an effective seal with the body.
Cooper S twin fuel tanks
Removal
19 Disconnect the battery negative lead. 20 Working in the rear luggage compartment
remove the trimmed floor panel.
21 Lift out the spare wheel. 22 Remove the fuel filler caps. 23 Unscrew the left-hand fuel tank drain plug
three turns and allow fuel to drain from both tanks into a suitable container. Do this in a well ventilated area, not in a garage or over an inspection pit. When drained, resecure the drain plug.
Left-hand tank
24 Disconnect the electrical connectors from
the fuel gauge sender unit.
25 Remove the tank strap securing bolt. 26 Detach the flexible pipe and the vent pipe
from the fuel tank. 27 Carefully ease the fuel tank towards the centre of the luggage compartment and lift away. 28 Refer to the information contained in paragraph 10.
Right-hand tank
29 Completely remove the battery, referring
to Chapter 5A if necessary.
30 Remove the tank strap securing bolt. 31 Detach the flexible hose from the left-
hand tank. 32 Move the tank slightly from its mountings, taking extreme care not to damage the flexible fuel pipes. 33 The fuel tank will still contain a small amount of petrol which should be drained into a small container when the flexible fuel pipe is disconnected.
34 Disconnect the flexible fuel pipe.
35 Finally detach the vent pipe from the tank
and lift the tank from the car. 36 Refer to the information contained in paragraph 10.
Refitting
37 Refitting either fuel tank is the reverse
sequence to removal. Make sure that the seal around the drain plug housing is water-tight.
10 Unleaded petrol - general
information and usage
Note: The information given in this Chapter is correct at the time of writing. If updated information is thought to be required, check
with a Rover dealer. If travelling abroad, consult one of the motoring organisations (or a similar authority) for advice on the fuel available.
1 The fuel recommended by Rover is given in the Specifications Section of this Chapter. 2 Models built up to October 1988 (as delivered from the factory) cannot use unleaded petrol; the valve seats fitted as standard will suffer serious premature wear without the protection of the petrol’s lead content. Only four-star leaded petrol should be used, irrespective of the engine’s compression ratio. Exceptions to this are those engines which have been modified as described in paragraph 5 below. 3 From October 1988 onwards (ie during the 1989 model year), improved components were gradually introduced at the factory to enable engines to run on 95 RON unleaded petrol; these vehicles can be identified by the green “95 RON unleaded petrol” label attached to the bonnet lock platform. These vehicles can use either unleaded or leaded petrol, without modification or risk of damage. 4 If you have a 1989 model and suspect that the label has become detached, check first with a Rover dealer whether the vehicle can or cannot use unleaded petrol; the VIN (Vehicle Identification Number) will be required for positive identification. Note, however, that as a general rule, 998 cc engines which can use unleaded petrol have the engine serial number prefix “99HE”.
4A•8 Fuel system - carburettor engines
9.5 Fuel tank and fittings – Saloon models
9.15 Fuel tank outlet pipe and fuel gauge sender unit (Estate, Van and
Pick-up models)
5 To use unleaded petrol on earlier models,
conversion kits are available (consisting basically of an exchange cylinder head known as “Green Packs”), through Rover dealers. Any vehicle which has had such a conversion will have the letter “U” stamped between the engine prefix and the start of the serial number, and can use either unleaded or leaded petrol without modification. Note:
Apart from any adjustment made during the fitting of a “Green Pack” no alteration should be made to the ignition timing or carburation settings.
6 Models equipped with a catalytic converter must be run on unleaded petrol only.
11 Carburettor - general
information
SU HS2 and HS4
The variable choke SU HS2 and HS4 carburettors are relatively simple instruments and are basically the same irrespective of type. They differ from most other carburettors in that, instead of having a number of various sized fixed jets for different conditions, only one variable jet is fitted to deal with all possible conditions.
The carburettor comprises four main assemblies; these are the carburettor body, the piston and dashpot assembly, the jet assembly and the float chamber. Fuel is carried from the float chamber to the base of the jet head by a nylon pipe, the float chamber being secured to the carburettor body by a horizontally positioned bolt and spacing washer.
The operation of the carburettor is as follows. Air passing rapidly through the carburettor creates a slight vacuum or depression over the jet, causing fuel to be drawn into the air stream, thus forming the fuel/air mixture. The amount of fuel drawn from the jet depends on the position of the tapered carburettor needle. This moves up or down the jet orifice according to engine load or throttle opening, thus effectively altering the size of the jet. This allows the right amount of fuel to be delivered for the prevailing road conditions.
The position of the tapered needle in the jet is determined by engine vacuum. The shank of the needle is held at its top end in a piston, which slides up and down the dashpot, in response to the degree of manifold vacuum. This is directly controlled by the throttle. The piston is necessary so that the depression over the jet needed to draw fuel into the air stream, can be kept approximately constant. At slow engine speeds, the air entering the carburettor would not be travelling fast enough to create sufficient vacuum to draw fuel from the jet. By allowing the piston to partially restrict the opening through the carburettor, the incoming air is speeded up, causing an adequate depression over the jet.
With the throttle fully open, the full effect of inlet manifold vacuum is felt by the piston, which has an air bleed into the carburettor venturi on the outside of the throttle. This causes the piston to rise fully, bringing the needle with it. With the throttle partially closed, only slight inlet manifold vacuum is felt by the piston (although on the engine side of the throttle, the vacuum is now greater), and the piston only rises slightly.
To prevent piston flutter, and to give a richer mixture when the accelerator is suddenly depressed, an oil damper and light spring are located inside the dashpot.
For cold starting, when fuel enrichment is necessary and very small amounts of air are drawn into the carburettor, actuation of the choke control causes the jet head to be lowered, thus effectively increasing the jet size.
The only portion of the piston assembly to come into contact with the piston chamber or dashpot is the actual central piston rod. All the other parts of the piston assembly, including the lower choke portion, have sufficient clearances to prevent any direct metal-to-metal contact, which is essential if the carburettor is to work properly.
The correct level of the petrol in the carburettor is determined by the level of the float in the float chamber. When the level is correct, the float rises and, by means of a lever resting on top of it, closes the needle valve in the cover of the float chamber. This closes off the supply of fuel from the pump. When the level in the float chamber drops, as fuel is used in the carburettor, the float sinks. As it does, the float needle comes away from its seat so allowing more fuel to enter the float chamber and restoring the correct level.
SU HIF44 and HIF38
The SU HIF44 and HIF38 carburettors are fitted to 1990-on Cooper models, and 1992-on 1275 cc models with open-loop catalytic converter respectively. These carburettors operate in a similar way to the SU HS2 and HS4 instruments described previously, but the float chamber has been incorporated into the main body of the carburettor, and a bi-metallic strip is fitted to the jet adjusting (mixture) screw mechanism; that is in order to compensate for the varying fuel densities which result from changes in fuel temperature.
12 Carburettor - removal and
refitting
2
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
SU HS2 and HS4 carburettors
Removal
1 Disconnect the battery negative lead. 2 Remove the air cleaner assembly as
described in Section 2. 3 Disconnect the distributor vacuum advance pipe from the carburettor (where fitted). 4 Slacken the retaining clip screw and withdraw the fuel inlet pipe from the top of the float chamber. Plug the disconnected pipe with a bolt or metal rod of suitable diameter. 5 Refer to Sections 3 and 5 and disconnect the accelerator and choke cables from the carburettor linkages. 6 Detach the throttle return spring from the bracket on the exhaust manifold clamp. On Cooper S models detach the throttle and throttle linkage return springs from the heat shield. On automatic transmission models detach the governor control rod fork end from the throttle lever 7 Detach the engine breather hose from the carburettor (where fitted). 8 Undo and remove the two nuts which secure the carburettor(s) to the inlet manifold studs and recover the spring washers. 9 Lift the carburettor carefully off the inlet manifold (see illustration). If twin carburettors are being removed, lift off both carburettors together to avoid damaging the linkages that join the two carburettor spindles. These can be removed after the carburettors are lifted clear of the manifold studs.
Refitting
10 Refitting the carburettor(s) is the reverse
sequence to removal, noting the following points:
a) Ensure that all mating surfaces are clean
and dry, and use new gaskets.
b) When refitting twin carburettors, ensure
that the linkages joining the two spindles are in position, and that the operating forks are engaged in the slots on the carburettor spindles.
c) Tighten the carburettor nuts evenly and
progressively, to avoid possible distortion of the mounting flange.
d) Refit the accelerator and choke cables
with reference to Sections 3 and 5.
SU HIF44 and HIF38 carburettors
Removal
11 Disconnect the battery negative lead. 12 Remove the air cleaner assembly as
described in Section 2. 13 On Cooper models, remove the carburettor heat shield.
Fuel system - carburettor engines 4A•9
4A
12.9 Removing the SU HS2 carburettor from the manifold
14 On 1992-on models with an open-loop
catalytic converter, release the retaining clip and disconnect the charcoal canister hose from the side of the carburettor. 15 On all models, disconnect the accelerator and choke cables from the carburettor linkages as described in Sections 3 and 5. Free the accelerator outer cable from its bracket, then release the retaining clip and detach the choke cable from the carburettor. 16 Disconnect the vacuum pipe from the top of carburettor mounting flange. 17 Release the retaining clip and disconnect the fuel supply hose from the carburettor. Plug the hose end to minimise fuel loss. 18 Release the retaining clip and disconnect the vent pipe from the float chamber. 19 Undo the mounting nuts and withdraw the carburettor from the inlet manifold, together with the throttle cable bracket, spacer and gaskets.
Refitting
20 Refitting is the reverse sequence to
removal, noting the following points.
a) Ensure that all mating surfaces are clean
and dry, and use new gaskets.
b) Tighten the carburettor nuts evenly and
progressively, to avoid possible distortion of the mounting flange.
c) Refit the accelerator and choke cables
with reference to Sections 3 and 5.
13 Carburettor (SU HS2 and
HS4) - fault diagnosis and
overhaul
3
Fault diagnosis
1 If a carburettor fault is suspected, always check first that the ignition timing is correctly set, that the spark plugs are in good condition and correctly gapped, that the throttle and choke cables are correctly adjusted, and that the air cleaner filter element is clean; refer to the relevant Sections of Chapter 1, Chapter 5B or this Chapter. If the engine is running very roughly, first check the valve clearances as described in Chapter 1, then check the compression pressures as described in Chapter 2A. 2 If careful checking of all the above produces no improvement, the carburettor must be removed for cleaning and overhaul. 3 Prior to overhaul, check the availability of component parts before starting work; note that most sealing washers, screws and gaskets are available in kits, as are some of the major sub-assemblies.
Overhaul
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
4 The SU carburettor is a straightforward unit to dismantle and service, but at the same time it is a delicate unit and clumsy handling can cause damage. In particular, it is easy to knock the
finely tapering needle out of true, and the greatest care should be taken to keep all the parts associated with the dashpot in a safe place and scrupulously clean. Prepare a clean and uncluttered working area before starting the dismantling, and have some small containers handy to store the small, easily-lost parts. 5 Begin by removing the carburettor(s) from the car as described in Section 12. Thoroughly clean the outside of the carburettor in paraffin or a suitable solvent and wipe dry. 6 Unscrew the piston damper assembly and remove it from the top of the dashpot (see
illustrations). 7 Mark the base of the dashpot and
carburettor body to ensure that on reassembly the dashpot is refitted in the same position. Now undo and remove the securing screws and lift off the dashpot. 8 Next lift off the piston spring and then carefully withdraw the piston and needle assembly from the carburettor body. Undo the small sunken retaining screw in the side of the piston and lift out the needle. On later types equipped with a spring-loaded needle, recover the guide collar from the needle, and the spring from the piston, after removing the needle assembly. 9 Undo and remove the three retaining screws and lift off the float chamber cover and gasket. The float may be released from the cover by gently tapping out the float hinge pin. The fuel cut-off needle valve can now be withdrawn from its seat in the cover and the needle seat unscrewed if required. 10 Unscrew the union nut securing the nylon fuel pipe to the base of the float chamber and carefully withdraw the pipe. Note the position of the gland, ferrule and rubber sealing washer on the end of the pipe and make sure that the rubber washer has not been left behind in the float chamber as the pipe is withdrawn. If so, hook it out carefully with a small screwdriver. 11 If there is a tamperproof cap in position around the jet adjusting nut at the base of the carburettor, prise it apart with a screwdriver and discard it. 12 Release the jet link lever return spring from the cam lever on the linkage. 13 Undo and remove the small screw or release the clip that secures the jet link arm to the jet. Move the jet link arm to one side and withdraw the jet assembly, complete with fuel pipe from the jet housing. 14 It is not normally necessary to carry out any further dismantling of the SU carburettor. However, if the throttle spindle, jet housing, or float chamber are worn, damaged, or in any way suspect, the remainder of the carburettor may be dismantled as described below. 15 Bend back the small tab washer and then undo and remove the nut securing the throttle lever to the spindle. Lift off the lever. 16 Straighten the splayed ends of the two throttle disc retaining screws and then mark the position of the disc in relation to the
spindle. Undo and remove the two screws, turn the disc to the fully open position and slide the disc out of the slot in the spindle. Note that new throttle disc retaining screws must be used when reassembling. 17 The spindle can now be removed from the carburettor body. 18 To remove the choke linkage undo the retaining pivot bolt and lift it off complete with linkage. 19 To dismantle the jet housing, first undo and remove the jet adjusting nut and lock spring. Next undo and remove the jet bearing locknut and withdraw the bearing. 20 The float chamber can be lifted off after unscrewing the retaining through-bolt. Recover the float chamber spacer, where fitted. 21 The carburettor is now completely dismantled with the exception of the piston lifting pin (omitted on later carburettors). The pin may be removed by prising off the small upper retaining circlip and lifting off the pin and spring. 22 Thoroughly clean all the carburettor components and dry thoroughly. 23 Carefully examine the throttle spindle and throttle disc for wear or distortion. If excessive wear is apparent on the spindle or spindle bushes in the carburettor body, air will enter the carburettor, altering the mixture strength and causing uneven running. The throttle spindle is obtainable separately, but if the bushes are worn, a complete carburettor body will normally have to be obtained. 24 Closely inspect the carburettor needle. If this has not been running centrally in the jet orifice then the needle will have a tiny ridge worn on it. If a ridge can be seen then the needle must be renewed. SU carburettor needles are made to very fine tolerances and should a ridge be apparent no attempt should be made to rub the ridge down with emery paper. 25 If the needle is worn, it is likely that the jet will also be worn. If this is the case, also renew the jet. Also inspect the outside of the jet head where it bears against the jet bearing. Wear can take place here due to the action of the choke control moving the jet up and down in the jet bearing. 26 The most critical components of the SU carburettor are the piston and dashpot assembly. Free movement of the piston in the dashpot is essential for the carburettor to function satisfactorily. The piston is machined to very fine tolerances so that it will not touch the side of the dashpot or carburettor body. If wear takes place on the centre guide tube or if deposits build up on the internal surfaces of the dashpot, the piston will come into contact with the side of the dashpot and will bind. This condition is known as piston sticking. If this condition cannot be improved after cleaning the inside of the dashpot and the piston with metal polish (harsh abrasives must not be used), then the piston and dashpot will have to be renewed. These two components are
4A•10 Fuel system - carburettor engines
Fuel system - carburettor engines 4A•11
4A
13.6a Exploded view of the SU HS2 carburettor
1 Body 2 Piston lifting pin 3 Spring 4 Circlip 5 Dashpot and piston assembly 6 Needle locking screw 7 Piston damper assembly 8 Washer for damper cap 9 Piston spring 10 Screw 11 Jet assembly 12 Jet bearing 13 Washer 14 Locknut for jet bearing 15 Lock spring 16 Jet adjusting nut 17 Jet needle 18 Float chamber body 19 Bolt 20 Float and lever assembly 21 Lever hinge pin 22 Float chamber lid assembly 23 Gasket 24 Needle and seat assembly 25 Screw 26 Spring washer 27 Baffle 28 Throttle spindle 29 Throttle disc 30 Screw 31 Throttle lever 32 Fast idle adjusting screw 33 Spring for adjusting screw 34 Throttle spindle nut 35 Tab washer 36 Idle speed adjusting screw 37 Spring for adjusting screw 38 Cam lever 39 Washer 40 Cam lever spring 41 Cam lever pivot bolt 42 Pivot bolt tube 43 Spring washer 44 Pick-up lever assembly 45 Jet link 46 Jet link retaining clip 47 Jet link securing screw 48 Bush 49 Spring for pick-up lever
4A•12 Fuel system - carburettor engines
13.6b Exploded view of the SU HS4 carburettor
1 Body 2 Piston lifting pin 3 Spring 4 Sealing washer 5 Plain washer 6 Circlip 7 Dashpot 8 Screw 9 Piston 10 Spring 11 Needle 12 Needle tension spring 13 Needle guide collar 14 Locking screw 15 Piston damper 16 Identification tag 17 Idle speed adjusting screw
and O-ring*
18 Idle speed adjusting screw
and spring 19 Gaskets 20 Insulator block 21 Float chamber and spacer 22 Gasket 23 Float 24 Hinge pin 25 Needle and seat 26 Float chamber cover 27 Baffle plate 28 Screw 29 Spring washer 30 Bolt 31 Spring washer 32 Plain washer 33 Throttle spindle 34 Throttle disc
35 Screw 36 Washer 37 Throttle return lever* 37a Throttle return lever 38 Progressive throttle (snail
cam) 39 Fast idle screw* 39a Fast idle screw and spring 40 Lockwasher 41 Nut 42 Jet assembly – Capstat type 43 Sleeve nut 44 Washer 45 Gland 46 Ferrule 47 Jet bearing 48 Jet locating nut 49 Jet adjustment nut and spring
50 Rod link and pick-up lever 51 Spring clip 52a Jet assembly 53a Pick-up lever non-Capstat
type 53b Link 53c Screw 54 Pivot bolt 55 Pivot bolt tube – inner 56 Pivot bolt tube – outer 57 Distance washer 58 Cam lever 59 Cam lever spring 60 Pick-up lever spring 61 Piston guide 62 Screw *Used with sealed adjustment
carburettors
only obtainable as matched pairs and cannot be interchanged. The piston and dashpot assembly are in a satisfactory condition if the piston, having been pushed right to the top of the dashpot, will drop under its own weight without any trace of binding. 27 Examine the float chamber needle valve and seat next. After high mileage, it is quite likely that a ridge will have formed on the face of the needle. This could prevent the needle valve from shutting off the fuel supply and cause flooding of the carburettor. This is quite a common occurrence on SU carburettors and unless the needle and seat appear to be in perfect condition, they should both be renewed. 28 Finally, check the condition of the float. If any signs of cracking or distortion are evident, which may allow fuel to enter, renew the float. 29 If the carburettor has been completely dismantled, begin reassembly by refitting the piston lifting pin and spring into the carburettor body and then refit the retaining circlip. 30 Place the float chamber in position and secure it in place, with the long retaining bolt inserted through the side of the carburettor body. 31 Refit the jet bearing, washer and locknut finger-tight only. Do not refit the lock spring or jet adjusting nut at this stage. 32 Refit the choke linkage and retaining pivot bolt. 33 Insert the throttle spindle into the carburettor body with the countersunk holes in the spindle facing outwards. Insert the throttle disc into the spindle, noting the assembly markings made during dismantling. Secure the disc to the spindle using new retaining screws, but do not tighten them. Snap the spindle open and shut to centralise the disc and make sure that the disc does not bind in the carburettor bore in any position. If necessary reposition the disc slightly. Now tighten the screws and spread their ends enough to prevent them from turning.
34 Slide the spacing washer and throttle lever onto the spindle, followed by the tab washer and retaining nut. Tighten the nut and bend over the tab washer. 35 On carburettors with a fixed jet needle, insert the needle into the piston, ensuring that the shoulder on the shank of the needle is flush with the underside of the piston. Refit and fully tighten the sunken retaining screw
(see illustrations). 36 On carburettors equipped with a spring-
loaded needle, fit the spring and guide collar to the needle and insert this assembly into the piston. Position the guide collar so that it is flush with the underside of the piston and position the needle so that the small etch mark is between the two piston transfer holes. Secure the assembly with the sunken retaining screw (see illustration). 37 If the jet housing has been removed, it will now be necessary to centralise the jet as follows. 38 With the jet bearing, washer and locknut in position as described in paragraph 31, refit
the jet adjusting nut, without the lock spring, and screw it up as far as it will go. Now slide the jet assembly into the jet housing. 39 Carefully refit the piston and needle assembly to the carburettor body, followed by the spring and dashpot. Align the previously made marks on the dashpot and carburettor body and then refit the securing screws. 40 Slacken the jet bearing locknut and hold the piston down using a pencil inserted through the damper opening. Now tighten the jet bearing locknut. 41 Lift the piston and allow it to fall under its own weight. A definite metallic click should be heard, as the piston falls and contacts the bridge in the carburettor body. 42 Now fully lower the adjusting nut and note whether the piston still falls freely. If not, slacken the jet bearing locknut and repeat the centring procedure. It may be necessary to carry out the centring operation several times, until the piston will fall freely with the adjusting nut at the top and bottom of its travel. 43 With the jet correctly centralised, slide out the jet assembly and unscrew the adjusting nut. Now place the lock spring in position and refit the adjusting nut and jet assembly. Secure the jet link arm to the jet with the screw or retaining clip. 44 The flexible jet fuel supply tube can now be refitted to the base of the float chamber. Ensure that the small rubber sealing washer, nut and gland are in position on the tube and that there is at least 5.0 mm of pipe protruding through the washer. Push the tube into the float chamber and tighten the union nut. 45 Refit the fuel cut-off needle and seat to the float chamber cover. Place the float in position and tap in the float hinge pin until equal amounts of the pin are protruding either side of the mounting lugs. 46 On early carburettors equipped with a brass float, invert the float chamber cover so that the needle valve is closed. It should now just be possible to place a
5
16 inch (8.0 mm)
diameter bar parallel to the float hinge pin and
Fuel system - carburettor engines 4A•13
4A
13.36 The spring-loaded needle assembly fitted to the later SU HS4 carburettors
13.35a Refit the fixed jet needle to the piston . . . 13.35b . . . and secure with the retaining screw
in the centre of the float chamber cover, without fouling the float. If the bar lifts the float or if the float stands clear of the bar, bend the float lever very slightly until the clearance is correct (see illustration). 47 Later carburettors fitted with plastic floats incorporate either a plain steel needle or a spring-loaded needle enclosed in a plastic sheath. The adjustment procedure for the plain steel needle type is the same as described in paragraph 46. Float level adjustment for spring-loaded needles is as follows. 48 Invert the float chamber cover so that the needle valve is closed but the spring is not compressed. The gap between the float and the flange on the float chamber cover, at the centre of the cover, should be between 3.18 mm and 4.76 mm (see illustration). If the gap is incorrect, bend the float lever slightly until the specified gap is obtained. In the case of floats having a moulded plastic hinge, increase or decrease the washer thickness under the needle seat to achieve the desired float level height. 49 Place a new gasket in position on the float chamber, refit the cover and secure it with the three retaining screws. 50 Fill the carburettor piston damper with the correct grade of oil, until the level is 13.0 mm
above the top of the hollow piston rod. Now refit the damper plunger. 51 To obtain an initial jet setting and to allow the engine to be started, screw the jet adjusting nut up until the jet is flush with the bridge in the carburettor body. Now screw the nut down two complete turns on non-sealed carburettors and three complete turns on sealed units. Note: The sealed type
carburettors are identified by the throttle adjusting screw which is recessed within the carburettor body.
52 The carburettor can now be refitted to the car as described in Section 12 and the idle speed and mixture adjustments carried out as described in Section 15.
14 Carburettor (SU HIF44 and
HIF38)) - fault diagnosis and
overhaul
3
Fault diagnosis
1 Refer to Section 13.
Overhaul
SU HIF44 carburettor
2 Remove the carburettor from the car as
described in Section 12, then clean the exterior surfaces thoroughly and wipe dry. 3 Mark the float chamber cover in relation to the carburettor body. Remove the screws, and withdraw the cover and sealing ring (see
illustration). 4 Unscrew and remove the mixture screw
and spring, and withdraw the seal. 5 Unscrew the jet retaining screw, and remove the spring. 6 Withdraw the jet and bi-metal lever assembly. Disengage the lever from the jet. 7 Unscrew and remove the float pivot and seal.
8 Withdraw the float and the needle valve. 9 Unscrew and remove the needle valve seat. 10 Unscrew and remove the piston damper,
and drain the oil. 11 Mark the dashpot in relation to the carburettor body. Remove the screws and withdraw the dashpot together with the piston. 12 Prise the clip from the top of the piston rod, then withdraw the piston and spring from the dashpot. 13 Unscrew the needle retaining grub screw. Remove the needle, guide and spring from the piston. 14 From underneath the main body, unscrew the jet bearing nut and withdraw the bearing. 15 Note how the spring is attached to the fast idle cam lever, then bend back the locktabs, unscrew the nut and remove the washer. 16 Hold the return spring against the main body, and use a screwdriver to prise the cam lever from the end of the cold start spindle. Remove the spring.
17 Remove the end cover and spindle seat. 18 Remove the two screws and withdraw the
retaining plate, cold start body and gasket. 19 Remove the O-ring from the end of the cold start spindle, and withdraw the spindle from the main body. Remove the cold start seal. 20 Dismantling of the throttle spindle is not recommended, unless the components are damaged or excessively worn. If they are, first note how the return spring is attached to the throttle lever. 21 Mark the throttle valve in relation to the spindle and main body. 22 Remove the throttle valve screws while supporting the spindle with a block of wood if necessary. 23 Open the throttle and withdraw the valve disc. 24 Remove any burrs from the spindle screw holes with a fine file. 25 Bend back the locktabs and unscrew the spindle nut. Remove the lockwasher, plain washer, throttle lever, and return spring. 26 From the opposite end of the spindle, loosen the nut and bolt, and remove the throttle damper lever. 27 Check the threaded end of the spindle and main body in relation to each other, then withdraw the spindle. Remove the two seals. 28 Clean all the components dry thoroughly. Examine each item for damage and excessive wear. In particular, check the throttle spindle and bearings for wear. If excessive, renewal of the spindle may be sufficient, but if the bearings are worn, it may be necessary to renew the complete carburettor, as new bearings are not always available. Check the needle valve and seating for excessive ridging. Examine the main body for cracks, and for security of the brass fittings and piston key. Check the tapered needle, jet and jet bearing for wear. Shake the float, and listen for any trapped fuel which may have entered through a small crack or fracture. Renew the components as necessary, and obtain a complete set of gaskets and seals, and two new throttle valve screws if necessary. 29 Clean the inside of the dashpot and the periphery of the piston with methylated spirit. Do not use any form of abrasive. Lubricate the piston rod with engine oil, and insert it into the dashpot. Hold the two components horizontal, and spin the piston in several positions. The piston must spin freely, without touching the sides of the dashpot. 30 Commence reassembly by fitting the throttle spindle and two seals to the main body. The seals must be slightly recessed in their housings. 31 Locate the return spring and throttle lever on the end of the spindle, and fit the plain washer, lockwasher, and nut. Tighten the nut while holding the lever, and bend over the locktabs to lock. 32 Engage the return spring with the throttle lever and main body, and tension the spring.
4A•14 Fuel system - carburettor engines
13.46 Method of setting the correct clearance of the float lever –
early carburettors
13.48 Method of setting the correct clearance of the float lever –
later carburettors
A 3.18 to 4.76 mm B Machined lip C Float lever adjustment point D Float needle and seat assembly E Lever hinge pin
Fuel system - carburettor engines 4A•15
4A
14.3 Exploded view of the SU HIF carburettor
1 Piston damper 2 Dashpot 3 Piston spring and clip 4 Piston 5 Needle retaining screw 6 Spring 7 Jet needle 8 Guide 9 Lifting pin 10 Lifting pin and circlip 11 Spindle seal 12 Throttle spindle 13 Throttle valve and screw 14 Return springs 15 Throttle lever and progressive
throttle cam 16 Fast idle adjustment screw 17 Idle speed adjustment screw 18 Spindle nuts and tab washers 19 Return spring lever 20 Mixture control lever and fast
idle cam 21 Return spring 22 Dust cap 23 Seal 24 Retaining plate 25 Cold start body 26 O-ring 27 Cold start spindle 28 Cold start seal 29 Main body 30 Jet bearing 31 Jet bearing nut 32 Jet assembly 33 Bi-metallic jet lever 34 Jet (mixture) adjusting screw
and seal 35 Jet retaining screw and spring 36 Float 37 Float pivot and seal 38 Needle valve 39 Needle valve seat 40 Fuel strainer 41 Float chamber cover 42 Cover seal 43 Screw and spring washer
33 Fit the throttle valve disc to the spindle in its original position, and insert the new screws, tightening them loosely (coat the threads with thread-locking fluid). 34 Open and close the throttle several times to settle the disc, then tighten the screws while supporting the spindle on a block of wood. Using a small chisel, spread the ends of the screws to lock them. 35 Locate the throttle damper lever loosely on the end of the spindle. 36 Locate the cold start seal in the main body with the cut-out uppermost. 37 Insert the cold start spindle (hole uppermost), and fit the O-ring. 38 Fit the cold start body with the cut-out uppermost, and the retaining plate with the slotted flange facing the throttle spindle. Use a new gasket, then insert and tighten the retaining screws. 39 Fit the spindle seat and end cover, followed by the spring, cam lever, lockwasher, and nut. Make sure that the spring is correctly engaged, then tighten the nut and bend over the locktabs to lock. 40 Insert the jet bearing and nut, and tighten the nut. 41 Connect the bi-metal lever with the fuel jet, making sure that the jet head moves freely in the cut-out. 42 Insert the mixture screw and seal into the main body. Fit the jet to the bearing, and at the same time engage the slot in the bi-metal lever with the small diameter of the mixture screw. 43 Insert the jet retaining screw with the spring, and tighten the screw. 44 Adjust the mixture screw so that the top of the jet is flush with the venturi bridge. 45 Insert and tighten the needle valve seat, and with the carburettor inverted, insert the needle valve. 46 Position the float, then insert the pivot and seal through the body and float, and tighten. 47 To check the float level adjustment, hold the carburettor inverted with the float keeping the needle valve shut. Using a straight edge and feeler blade, check that the centre portion of the float is 1.0 ± 0.5 mm below the surface of the float chamber face (see illustration). If not, bend the tab which contacts the needle valve as necessary. 48 Fit the float chamber cover in its original position, together with a new sealing ring. Tighten the screws in diagonal sequence. 49 Insert the spring, needle, and guide into the piston with the guide etch marks facing the dashpot transfer holes, and with the bottom face of the guide flush with the bottom face of the piston (see illustration 13.36). 50 Insert and tighten the guide retaining grub screw. 51 Lower the piston and needle assembly into the main body, at the same time engaging the slot with the piston key.
52 Locate the spring over the piston rod.
53 Hold the dashpot directly over the piston
with its location mark aligned with the mark on the body, then lower it over the spring and piston rod. It is important not to tension the spring by twisting the dashpot. 54 Insert and tighten the dashpot retaining screws. Lift the piston with a finger, then release it and check that it returns to the venturi bridge without any assistance. If not, it may be necessary to loosen the retaining screws and slightly reposition the dashpot. 55 Hold the piston fully up, then fit the clip to the top of the piston rod. 56 Pour the specified type of oil into the top of the dashpot until the level is 13.0 mm above the top of the hollow piston rod. Refit and tighten the piston damper.
SU HIF38 carburettor
57 At the time of writing, no specific
information on the HIF38 carburettor fitted to the 1992-on 1275 cc models was available. However the carburettor is really only a slightly smaller version of HIF44 (38 mm bore instead of 44 mm) it is otherwise identical. Therefore, the carburettor can be overhauled using the information given above, noting that it will be necessary to refer to a Rover dealer for correct float height measurements; those given in paragraph 47 are only applicable to the HIF44 carburettor.
15 Carburettor (SU HS2 and
HS4) - idle speed and mixture
adjustment
3
Preliminary information
1 Three adjustments are possible on the SU carburettor. These are the engine idling speed, fast idling speed and mixture strength. The mixture strength is particularly important as the initial setting, carried out with the engine idling, determines the mixture strength throughout the entire engine speed range. A good indication as to whether carburettor adjustment is necessary can be gained by checking the colour of the exhaust tailpipe and listening to the note of the exhaust at idling speed. If the tailpipe is black and the engine appears to be hunting, it is quite likely that the mixture is too rich. If the exhaust is light grey or white in appearance, accompanied by a rhythmic puffing sound, this would indicate a weak mixture. Ideally, the exhaust should be a medium grey colour and emit a steady even drone. The colour of the spark plugs will also give a good indication as to the mixture strength and general engine condition (see Chapter 1). These checks should only be carried out after
4A•16 Fuel system - carburettor engines
14.47 SU HIF carburettor float level adjustment “A”
1 Type 1 float 2 Type 2 float A = 1.0 ± 0.5 mm
a good run of about 5 to 10 miles. Idling in city traffic and stop/start motoring is bound to cause excessively dark exhaust pipe and spark plug deposits. 2 Before carrying out any adjustments to the carburettor, ensure that the ignition system is in good condition, that the spark plugs, contact breaker points and ignition timing settings are correct, and that the engine is at normal operating temperature. Check also that the carburettor dashpot oil damper is topped up to the correct level with the specified grade of oil. 3 Depending on year of manufacture either a sealed or non-sealed carburettor may be fitted. Early models are equipped with the non-sealed type, identified by the throttle and fast idle adjusting screws which are clearly visible and retained by a tension spring or locknut. On the sealed carburettors the throttle adjusting screw is located in a recessed hole in the carburettor body and may be covered by a small circular metal cap. 4 Carburettor adjustment is carried out as follows, according to type.
Adjustment
Single carburettor installations - non­sealed type
5 Remove the air cleaner assembly as
described in Section 2.
6 Connect a tachometer to the engine (if one is not already fitted to the car), following the manufacturer’s instructions. If your ears can attune to slight changes in engine rpm or to alterations of the exhaust note, then it is possible to carry out the adjustments without the use of a tachometer. 7 Set the engine idling speed by turning the throttle adjusting screw until the specified idling speed is obtained (see illustrations).
Note: If the throttle adjusting screw is secured by a locknut, slacken the locknut before turning the adjusting screw and leave it slackened until all the carburettor adjustments have been completed.
8 To check the mixture strength, press the piston lifting pin on the side of the carburettor upwards, against light spring resistance, until it comes into contact with the piston. Now press it up a further 1.0 mm and listen to the engine speed. This will indicate one of the following:
a) If the speed of the engine increases
appreciably, the mixture is too rich.
b) If the engine speed immediately
decreases or the engine stalls, the mixture is too weak.
c) If the engine speed remains constant or
increases very slightly, the mixture is correct.
9 To enrich the mixture, rotate the jet adjusting nut located at the base of the carburettor in a clockwise direction as viewed from above, ie downward. To weaken the mixture, rotate the jet adjusting nut anti­clockwise as viewed from above, ie upward, while at the same time pushing the jet assembly upwards against the nut. When altering the mixture strength, only turn the nut one flat at a time and check the mixture with the lifting pin each time. 10 It is quite likely that there will be a slight increase or decrease in engine rpm, after the mixture adjustment has been made. This should be corrected by turning the throttle adjusting screw, until the specified idling speed is again obtained. 11 With the engine idling at the specified speed and the mixture correctly adjusted, check the fast idle adjustment as follows. 12 Rotate the choke linkage on the side of the carburettor, to the point where the linkage just starts to lower the jet. Hold the linkage in this position and rotate the fast idle adjustment screw, until the specified engine fast idle speed is obtained. 13 When all adjustments are complete, disconnect the tachometer, refit the air cleaner and road test the car, carrying out any small adjustments that may be necessary, on the road.
Fuel system - carburettor engines 4A•17
4A
15.7a Carburettor adjustment points – SU HS2
1 Throttle adjusting screw 2 Fast idle adjusting screw 3 Float chamber bolt
4 Jet link securing screw 5 Jet adjusting nut 6 Jet locknut
1 Fast idle adjusting screw 2 Jet adjusting nut
3 Governor control rod
(automatic transmission)
4 Throttle adjusting screw
15.7b Carburettor adjustment points – SU HS4
Single carburettor installations ­sealed type without open-loop catalytic converter
14 Remove the air cleaner assembly as
described in Section 2. 15 If the tamperproof seals are still in position over the throttle adjusting screw and mixture adjusting nut, remove and discard them (see illustration). The seal over the throttle adjusting screw can be hooked out of the recess using a small screwdriver. The seal on the jet adjusting nut can be removed by prising it open with a screwdriver and then lifting away the two halves. 16 Connect a tachometer to the engine (if one is not already fitted to the car), following the manufacturer’s instructions. If your ears can attune to slight changes in engine rpm or to alterations of the exhaust note, then it is possible to carry out the adjustments without the use of a tachometer. 17 Set the engine idling speed, by turning the throttle adjusting screw until the specified idling speed is obtained. 18 Turn the jet adjusting nut located at the base of the carburettor in a clockwise or anti­clockwise direction, one flat at a time, until the
fastest possible engine speed consistent with even running is obtained. Turning the nut clockwise as viewed from above, ie downward, enriches the mixture. Turning the nut anti-clockwise as viewed from above, ie upward, weakens the mixture. 19 It is quite likely that there will be a slight increase or decrease in engine rpm after the mixture adjustment has been made. This should be corrected by turning the throttle adjusting screw until the specified idling speed is again obtained. 20 The remainder of the adjustment procedure is the same as described previously for non-sealed carburettors in paragraphs 11 to 13.
Single carburettor installations ­sealed type with open-loop catalytic converter
21 On 1992-on 998 cc models equipped with
an open-loop catalytic converter, the idle speed and mixture adjustments can be carried out as described previously in paragraphs 14 to 20, but using an exhaust gas analyser to check the CO content of the exhaust gas. 22 The gas analyser should be used in accordance with the maker’s instructions and connected to the take-off point at the top of the exhaust system front pipe. To do this, it will first be necessary to jack up the front of the car and support it on axle stands. 23 Unscrew the threaded plug from the front pipe, and screw the gas sampling pipe adapter into the threaded hole; the adapter can be obtained from a Rover dealer. The gas analyser should then be connected to the end of the sampling pipe.
24 On completion, unscrew the sampling pipe, then refit the threaded plug and tighten it securely.
Twin carburettor installations
25 Before adjusting the mixture strength on
models fitted with twin carburettors, it is necessary to ensure that the volume of air passing through each carburettor is the same. This is done as follows. 26 Remove the air cleaner assembly as described in Section 2. 27 Slacken the two clamp bolts on the throttle spindle operating arms and the two clamp bolts on the choke spindle operating arms (see illustration). 28 Start the engine without depressing the accelerator and allow it to idle. 29 Using a proprietary balancing meter, in accordance with the manufacturer’s instructions, balance the carburettors by altering the throttle adjusting screws until the airflow through both carburettors is the same. 30 Alternatively, use a length of small bore tubing, such as heater hose, approximately 457 mm long, to compare the intensity of the inlet hiss on both carburettors. Turn the throttle adjusting screws until the hiss sounds the same in both carburettors. It should be noted that this method is not really recommended, as it tends to be somewhat less accurate, and certainly more difficult, than using a balancing meter. 31 When the two carburettors are balanced, bring the engine idling speed back to the specified rpm by turning both throttle adjusting screws by equal amounts. 32 Now tighten the two clamp bolts, on the throttle spindle operating arms, making sure
4A•18 Fuel system - carburettor engines
15.15 The tamperproof caps fitted to the later type sealed carburettors
1 Throttle adjusting screw cap 2 Throttle adjusting screw showing
cap in position 3 Jet adjusting nut seals 4 Jet adjusting nut
15.27 Throttle and choke linkage – Cooper S models
1 Throttle spindle operating arms 2 Choke spindle operating arms
that a slight clearance exists between the peg and the lower edge of the fork. Ensure also that the arms are positioned in such a way that both carburettor throttles open at the same time, when the accelerator pedal is depressed. If necessary, reposition one of the arms slightly to achieve this condition. 33 Now adjust the mixture strength for each carburettor using the procedure described in paragraphs 8 and 9. 34 If the idling speed requires adjustment after setting the mixture, turn both throttle adjusting screws by an equal amount in the desired direction. 35 The choke spindle operating arms can now be positioned and tightened using the method described previously for the throttle operating arms. 36 Finally, adjust the fast idle speed as follows. 37 Pull out the choke control knob or operate the linkage by hand, until the linkage just starts to lower the jets. Hold the linkage in this position and turn the fast idle adjusting screws, on both carburettors, until the specified fast idle speed is obtained and both carburettors are passing the same volume of air. 38 Adjustment of the carburettors is now complete. Refit the air cleaner and carry out a thorough road test.
16 Carburettor (SU HIF44 and
HIF38) - idle speed and
mixture adjustment
3
Note: A tachometer and accurately calibrated exhaust gas analyser (CO meter) will be required for the following adjustments. If these
instruments are not available, the car should be taken to a Rover dealer for the work to be carried out.
Preliminary information
1 Refer to Section 15, paragraphs 1 and 2, then check the following items:
a) The crankcase ventilation hoses are
secure and in good condition (Chapter 4C).
b) The choke cable is correctly adjusted
(Section 5).
c) The accelerator cable is correctly
adjusted (Section 3).
d) The fast idle screw is correctly adjusted,
so that there is clearance between the screw and the cam with the choke control off.
2 Run the engine to normal operating temperature. Driving the car on the road for approximately 4 miles will achieve this. 3 The adjustments should be completed within two minutes of the engine reaching normal temperature, before the electric cooling fan operates. If the adjustments are not completed within the two minutes or if the cooling fan operates, wait for the fan to switch off, then increase the engine speed to 2000 rpm for approximately 30 seconds. The adjustments can then be resumed. 4 To adjust the mixture setting on Cooper models, it will be necessary to unscrew the plug from the gas sampling pipe which is situated on the right-hand end of the cylinder head, and connect an exhaust gas analyser to the end of the pipe (see illustration). On all other models, the exhaust gas analyser should be connected to the take-off point on the exhaust system front pipe, using a gas sampling pipe adapter (which can be obtained
from a Rover dealer). To fit the pipe, jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”). Unscrew the threaded plug from the exhaust system front pipe, screw the gas sampling pipe into the threaded hole, and connect the exhaust gas analyser to the end of the sampling pipe.
Adjustment
Note: If it has been noted that the engine idle speed has become erratic, and a high CO % reading is obtained during the following procedure, it is likely that the carburettor needle valve is faulty. Rover have produced a modified needle valve kit to overcome this problem. Refer to your Rover dealer for further information.
5 Check that all electrical components are switched off. 6 Connect a tachometer to the engine in accordance with the maker’s instructions. 7 Allow the engine to idle, and check that the idle speed is as given in the Specifications. If adjustment is necessary, turn the screw located on the dashpot base as necessary
(see illustration). 8 With the exhaust gas analyser connected
as described in paragraph 4, and the engine idling, check that the mixture CO % is as given in the Specifications. If not, turn the adjustment screw located on the side of the carburettor body. Turn the screw by small increments, and allow the reading to stabilise between adjustments. 9 If necessary, re-adjust the idling speed as described in paragraph 7. 10 Note that if the CO % is adjusted near the
3.0% upper limit, the efficiency of the catalytic converter will be reduced. If the CO reading is
Fuel system - carburettor engines 4A•19
4A
16.4 Gas sampling pipe location (arrowed) on 1990-on Cooper models
16.7 Adjusting location points on the SU HIF
then taken from the exhaust tailpipe, there may be little difference between the two readings. However, this does not mean that the catalytic converter is functioning correctly, and it will not adversely affect the unit. 11 Check the fast idling speed by pulling out the choke until the arrow on the carburettor fast idle cam is aligned with the adjustment screw. If adjustment is necessary, turn the fast idle screw. 12 Stop the engine and disconnect the tachometer and exhaust gas analyser. On Cooper models, refit the plug to the sampling pipe. On all other models, remove the sampling pipe, refit and tighten the threaded plug, and lower the vehicle to the ground.
17 Anti-run-on valve (1990-on
Cooper models) - removal
and refitting
1
Removal
1 The anti-run-on valve is mounted onto a bracket in the right-hand rear corner of the engine compartment. Its function is to prevent the engine running-on (“dieseling”) after the ignition is switched off. If the valve is disconnected or damaged, it may prevent the engine from running or idling smoothly. 2 To remove the valve, disconnect the wiring connector and both hoses from it. 3 Unscrew the bracket retaining bolt, and remove the valve complete with its bracket.
Refitting
4 Refitting is a reverse of removal, ensuring that the wiring connector and hoses are securely connected.
18 Inlet manifold - removal and
refitting
2
Removal
Note: On vehicles fitted with emission control equipment it will be necessary to remove certain additional fittings, hoses and brackets to provide access to the inlet manifold. The items requiring removal will be obvious after a visual inspection, and full information regarding their removal will be found in Part C of this Chapter.
1 Refer to Section 12 and remove the carburettor(s) from the inlet manifold. 2 On models fitted with a brake servo, slacken the retaining clip screw and remove the vacuum hose from the union on the inlet manifold. 3 If working on Cooper S models, undo and remove the nuts, large flat washers and spring washers securing the manifold to the cylinder head. Lift off the manifold. On all other models proceed as follows. 4 Chock the rear wheels then jack up the front of the car and support it on axle stands (see “Jacking and vehicle support”).
5 From underneath the car, undo and remove the nut and bolt securing the exhaust front pipe support strap to the transmission bracket. 6 Undo and remove the two bolts and nuts securing the two halves of the exhaust manifold clamp to the front pipe. Lift away the clamp assembly. 7 Undo and remove the six nuts and flat washers securing the manifold to the cylinder head (see illustration). 8 Lift off the hot air shroud, where fitted, and then slide the inlet and exhaust manifold assembly off the studs and withdraw it from the engine. Recover the manifold gasket.
Refitting
9 Refitting is the reverse sequence to removal bearing in mind the following points:
a) Ensure that the mating surfaces of the
manifold and cylinder head are clean, and use a new gasket.
b) Refit the exhaust manifold-to-front pipe
clamp before tightening the front pipe support strap bolt.
4A•20 Fuel system - carburettor engines
18.7 Inlet and exhaust manifold assembly
1 Manifold and gasket 2 Carburettor insulating block
3 Retaining nuts 4 Manifold-to-front pipe clamp
4B
Chapter 4 Part B:
Fuel system - fuel injection engines
General
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rover/Motorola Modular Engine Management System, using ECU-
controlled single-point injection (MEMS-Spi) and speed/density method of airflow measurement
Fuel system data
Fuel pump type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electric, immersed in fuel tank
Fuel pump regulated pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 bar ± 4%
Injector and pressure regulator unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . JZX 3300
Throttle potentiometer voltage:
Throttle closed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 1 volt
Throttle open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 to 5 volts
Idle speed - nominal value, for reference only . . . . . . . . . . . . . . . . . . . . 850 ± 25 rpm
Idle mixture CO % . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5% maximum
Recommended fuel
Minimum octane rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 RON unleaded only
Torque wrench settings Nm lbf ft
Fuel pump nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6
Throttle body assembly nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Injector housing fuel pipe union nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 18
Injector housing fuel pipe adapters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 18
Injector housing screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4
Inlet air temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5
Manifold retaining nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 16
Brake servo vacuum hose union bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 37
Fuel tank breather two-way valve nuts . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6
Accelerator cable - removal, refitting and adjustment . . . . . . . . . . . 4
Air cleaner air temperature control system - general information,
testing and component renewal . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Air cleaner assembly - removal and refitting . . . . . . . . . . . . . . . . . . . 2
Fuel gauge sender unit - removal and refitting . . . . . . . . . . . . . . . . . 10
Fuel injection system - testing and adjustment . . . . . . . . . . . . . . . . . 12
Fuel injection system components - removal and refitting . . . . . . . . 13
Fuel system - depressurisation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Fuel system - pressure check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Inlet manifold PTC heater - general information and component
renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Underbody and fuel/brake line check . . . . . . . . . . . . . . .See Chapter 1
Underbonnet check for fluid leaks and hose condition . .See Chapter 1
Unleaded petrol - general information and usage . . . . . . . . . . . . . . . 11
4B•1
Specifications
Contents
Easy, suitable for
novice with little experience
Fairly easy, suitable for beginner with some experience
Fairly difficult,
suitable for competent DIY mechanic
Difficult, suitable for experienced DIY mechanic
Very difficult,
suitable for expert DIY or professional
Degrees of difficulty
5
4
3
2
1
1 General information and
precautions
General information
The fuel system consists of a fuel tank, situated at the rear of the car, with an electric fuel pump immersed in it, a fuel filter, fuel feed and return lines, and the throttle body assembly (which incorporates the single fuel injector and the fuel pressure regulator), as well as the engine management electronic control unit (ECU) and the various sensors, electrical components and related wiring. The air cleaner contains a disposable paper filter element, and incorporates a flap valve air temperature control system, which allows cold air (from the outside of the car) and warm air (heated by the exhaust manifold) to enter the air cleaner in the correct proportions.
To reduce emissions and to improve driveability when the engine is cold, the inlet manifold is heated by the cooling system coolant and by an electric pre-heater system. Mixture enrichment for cold starting is a pre­programmed function of the system.
The ECU fully controls both the ignition and fuel injection systems, integrating the two in a complete engine management system; refer to Chapter 5B for information on the ignition side of the system.
The Rover/Motorola Modular Engine Management System uses ECU-controlled single-point injection (MEMS-Spi) and the speed/density method of airflow measurement. The whole system is best explained if considered as three sub-systems; the fuel delivery, air metering and electrical control systems.
The fuel delivery system incorporates the fuel tank with an electric fuel pump (immersed in a swirl pot to prevent aeration of the fuel) inside it. When the ignition is switched on, the pump is supplied with current via the fuel pump relay, under the control of the ECU; the pump feeds petrol via a non-return valve (to prevent fuel draining out of the system components and back to the tank when the pump is not working) to the fuel filter, and from the filter to the injector. Fuel pressure is controlled by the pressure regulator, which lifts to allow excess fuel to return to the tank swirl pot, where a venturi causes the returning fuel to draw cool fuel from the tank into the swirl pot. In the event of sudden deceleration (ie, an accident) an inertia switch cuts off the power to the pump, so that the risk of fire from fuel spraying out of broken fuel lines under pressure is minimised.
The air metering system includes the inlet air temperature control system and the air cleaner, but the main components are in the throttle body assembly. This incorporates the injector (which sprays fuel onto the back of the throttle disc), the throttle potentiometer (which is linked to the throttle disc spindle,
and sends the ECU information on the rate of throttle opening by transmitting a varying voltage), and the stepper motor, (which is controlled by the ECU, and operates the throttle disc spindle lever via a cam and pushrod to provide idle speed control).
The electrical control system consists of the ECU, with all the sensors that provide it with information, and the actuators by which it controls the whole system’s operation. The ECU’s manifold absolute pressure (MAP) sensor is connected, by hoses and a fuel (vapour) trap mounted on the bulkhead, to the inlet manifold; variations in manifold pressure are converted into graduated electrical signals, which are used by the ECU to determine the load on the engine. The inlet air temperature sensor is self-explanatory; the crankshaft sensor provides the engine speed and crankshaft position; the coolant temperature sensor supplies the engine temperature, the accelerator pedal switch tells the ECU when the accelerator is closed; the throttle potentiometer is explained above, and the function of the lambda sensor is explained in Part C of this Chapter. The ECU also senses battery voltage, and can adjust the injector pulses width and use the stepper motor to increase the idle speed and, therefore, the alternator output it if is too low. Short-circuit protection and diagnostic capabilities are incorporated; the ECU can both receive and transmit information via the diagnostic connector, thus permitting engine diagnosis and tuning by Rover diagnostic equipment. If either the coolant temperature sensor, the inlet air temperature sensor or the manifold absolute pressure sensor circuits should fail, the ECU has a back-up facility which assumes a valve corresponding to a coolant temperature of 60ºC, an inlet air temperature of 35ºC and an engine load based on the engine speed and throttle position; these are used to implement a back­up air/fuel mixture ratio.
All these signals are compared by the ECU, using digital techniques, with set values pre­programmed (mapped) into its memory. Based on this information, the ECU selects fuel and ignition settings appropriate to those values, and controls the ignition HT coil (varying the ignition timing as required), the fuel injector (varying its pulse width - the length of time the injector is held open - to provide a richer or weaker mixture, as appropriate), the stepper motor (controlling the idle and fast idle speeds), the fuel pump relay (controlling the fuel delivery), the manifold heater relay (controlling the inlet manifold pre-heater system) and the main relay, the purge control valve, and the lambda sensor and relay, accordingly. The mixture, idle speed and ignition timing are constantly varied by the ECU to provide the best settings for cranking, starting and engine warm-up (with either a hot or cold engine), idle, cruising, and acceleration. A rev-limiter circuit is built into the ECU, which switches off the
injector earth (ie, the fuel supply) if the engine speed exceeds the recommended limit. The injector earth is also switched off on the overrun, to improve fuel economy and reduce exhaust emissions.
The ECU idle control is an adaptive system; it learns the engine load and wear characteristics over a period of time, and adjusts the idle speed to suit. If the ECU is renewed, or one from another car is fitted, it will take a short period of normal driving for the new ECU to learn the engine’s characteristics and restore full idle control.
Precautions
Warning: Petrol is extremely flammable - great care must be taken when working on any part
of the fuel system. Do not smoke or allow any naked flames or uncovered light bulbs near the work area. Note that gas powered domestic appliances with pilot flames, such as heaters, boilers and tumble dryers, also present a fire hazard ­bear this in mind if you are working in an area where such appliances are present. Always keep a suitable fire extinguisher close to the work area and familiarise yourself with its operation before starting work. Wear eye protection when working on fuel systems and wash off any fuel spilt on bare skin immediately with soap and water. Note that fuel vapour is just as dangerous as liquid fuel; a vessel that has just been emptied of liquid fuel will still contain vapour and can be potentially explosive. Petrol is a highly dangerous and volatile liquid, and the precautions necessary when handling it cannot be overstressed.
Many of the operations described in this Chapter involve the disconnection of fuel lines, which may cause an amount of fuel spillage. Before commencing work, refer to the above Warning and the information in “Safety first” at the beginning of this manual.
When working with fuel system components, pay particular attention to cleanliness - dirt entering the fuel system may cause blockages which will lead to poor running.
Note: Residual pressure will remain in the fuel lines long after the vehicle was last used, when disconnecting any fuel line, it will be necessary to depressurise the fuel system as described in Section 6.
2 Air cleaner assembly -
removal and refitting
1
Removal
1 Slacken and remove the three screws securing the air cleaner assembly to the throttle body (see illustration).
4B•2 Fuel system - fuel injection engines
2 Lift up the assembly, then disconnect the wiring connector from the air temperature sensor, and the inlet manifold vacuum pipe from the thermac valve (see illustrations). 3 Remove the air cleaner assembly, and recover its sealing ring from the throttle body flange.
Refitting
4 Refitting is the reverse sequence to removal, ensuring that the sealing ring is correctly located on the throttle body flange.
3 Air cleaner air temperature
control system - information,
testing and component renewal
1
General information
1 The system is controlled by a thermac valve/switch mounted in the air cleaner assembly; when the engine is started from cold, the switch is closed, to allow inlet manifold depression to act on the air temperature control valve in the inlet duct. This raises a vacuum diaphragm in the valve assembly, and draws a flap valve across the cold air inlet, thus allowing only (warmed) air from the exhaust manifold to enter the air cleaner. 2 As the temperature of the exhaust-warmed air in the air cleaner rises, a bi-metallic strip in the thermac switch deforms, opening the switch to shut off the depression in the air temperature control valve assembly. The flap is lowered gradually across the hot air inlet until, when the engine is fully warmed-up to normal operating temperature, only cold air from the front of the inlet duct is entering the air cleaner.
Testing
3 To check the system, allow the engine to cool down completely, then unclip the inlet duct from the air cleaner body; the flap valve in the duct should be securely seated across the hot air inlet. Start the engine; the flap should immediately rise to close off the cold air inlet, and should then lower steadily as the engine warms up, until it is eventually seated across the hot air inlet again.
4 To check the thermac switch, disconnect the vacuum pipe from the control valve when the engine is running, and place a finger over the pipe end. When the engine is cold, full inlet manifold vacuum should be present in the pipe, and when the engine is at normal operating temperature, there should be no vacuum in the pipe. 5 To check the air temperature control valve, unclip the inlet duct from the air cleaner body; the flap valve should be securely seated across the hot air inlet. Disconnect the vacuum pipe, and suck hard at the control valve stub; the flap should rise to shut off the cold air inlet. 6 If either component is faulty, it must be renewed as described below.
Component renewal
Thermac switch
7 Remove the air cleaner assembly as
described in Section 2. 8 Release the lid retaining clips, then remove the lid and withdraw the air cleaner filter element.
9 Disconnect the vacuum pipe (see illustration), then bend up the tags on the
switch clip. Remove the clip, then withdraw the switch and its seal. 10 Refitting is the reverse sequence to removal, ensuring that the switch mating surfaces are clean, and that the switch and seal are correctly located before fastening the clip.
Air temperature control valve
11 Disconnect the vacuum pipe from the
valve, then unclip the inlet duct from the air cleaner and remove it from the engine compartment. 12 The air temperature control valve can be renewed only with the complete inlet duct assembly. If a new inlet duct assembly is being fitted, undo the three screws securing the hot air inlet adapter plate to the bottom of the duct, and transfer the adapter plate to the new duct (see illustration). 13 Clip the duct into position in the air cleaner, and reconnect the vacuum pipe.
4 Accelerator cable - removal,
refitting and adjustment
2
Removal
1 Remove the air cleaner assembly as described in Section 2. 2 Remove the engine management ECU as described Section 13. 3 Slacken the accelerator cable locknuts, and free the outer cable from its mounting bracket. Release the inner cable from the throttle cam. 4 Work back along the outer cable, releasing it from any relevant retaining clamps and ties, and from the engine compartment bulkhead. 5 Working from inside the car release the heater duct from underneath the driver’s side of the facia panel, to gain access to the upper end of the accelerator pedal.
Fuel system - fuel injection engines 4B•3
4B
2.1 Undo the three retaining screws . . . 2.2a . . . then lift up the air cleaner assembly, and disconnect the intake air
temperature sensor wiring connector . . .
2.2b . . . and the thermac valve vacuum pipe
3.9 Disconnecting the vacuum pipe from the thermac valve
3.12 Removing the air cleaner intake duct adapter
6 Remove the accelerator cable retaining clip,
then release the cable from the upper end of the accelerator pedal. Return to the engine compartment, and withdraw the cable from the bulkhead.
Refitting and adjustment
7 Refitting is the reverse sequence to removal, ensuring that the cable is correctly routed. Prior to tightening the cable locknuts, the cable should be adjusted as follows. 8 With the pedal fully released, position the locknuts so that there is equal clearance present on each side of the throttle lever at the lost motion link and no slack in the cable (see illustration). Have an assistant fully depress the pedal, and check that the throttle cam opens fully, then check that it returns to the at-rest position when released. 9 To adjust the cable, switch on the ignition and position the stepper motor by moving the cam only to open, and fully close the throttle (see illustration). Note that it is essential for accurate positioning of the stepper motor that the accelerator pedal switch contacts remain closed, so that the ECU recognises the throttle movement as a command, and indexes the stepper motor. 10 Slacken the adjuster locknut, then tighten the adjuster nut until the clearance is equal on each side of the throttle lever at the lost motion link, tighten the locknut without disturbing this setting (see illustration). Recheck the adjustment, and switch off the ignition.
5 Accelerator pedal - removal
and refitting
1
Refer to Part A, Section 4.
6 Fuel system -
depressurisation
1
Note: Refer to the warning note in Section 1 before proceeding.
Warning: The following procedure will merely relieve the pressure in the fuel system -
remember that fuel will still be present in the system components, and take precautions accordingly before disconnecting any of them.
1 The fuel system referred to in this Section is defined as the tank mounted fuel pump, the fuel filter, the fuel injector and the pressure regulator in the injector housing, and the metal pipes and flexible hoses of the fuel lines between these components. All these contain fuel which will be under pressure while the engine is running and/or while the ignition is switched on. The pressure will remain for some time after the ignition has been switched off, and must be relieved before any of these components are disturbed for servicing work.
2 Disconnect the battery negative lead.
3 Place a suitable container beneath the
relevant connection/union to be disconnected, and have a large rag ready to soak up any escaping fuel not being caught by the container. 4 Loosen the connection or union nut (as applicable) slowly to avoid a sudden release of pressure, and position the rag around the connection to catch any fuel spray which may be expelled. Once the pressure is released, disconnect the fuel line, and insert suitable plugs to minimise fuel loss and prevent the entry of dirt into the fuel system.
7 Fuel system - pressure check
4
Note: The following procedure is based on the use of the Rover pressure gauge and adapter (service tool number 18G1500).
1 Depressurise the fuel system as described in Section 6, then release the retaining clip and disconnect the flexible fuel feed hose at its union to the metal fuel pipe which is secured to the engine compartment bulkhead, just behind the throttle body assembly; the feed pipe is the lower of the two. 2 Connect the gauge into the fuel line between the hose and pipe, and check that it is securely retained. 3 Reconnect the battery and start the engine; the pressure should be steady at the specified regulated injection pressure. Stop the engine and watch the gauge; the pressure drop in the first minute should not exceed 0.7 bars. 4 If the regulated pressure recorded was too high, the pressure regulator must be renewed; this means renewing the complete injector housing assembly. 5 If the pressure first recorded was too low, or if it falls too quickly, check the system carefully for leaks. If no leaks are found, first
4B•4 Fuel system - fuel injection engines
4.10 . . . then adjust the locknut and adjuster nut as described in text
4.8 Accelerator cable adjustment - fuel-injected models
1 Throttle lever-to-lost motion
link clearance should be equal on each side
2 Adjuster locknut 3 Adjuster nut
4.9 To adjust the accelerator cable, index the stepper motor . . .
renew the fuel filter (see Chapter 1), then check the pump by substituting a new one, and recheck the pressure. If the pressure does not improve, the fault is in the pressure regulator, and the complete injector housing assembly must be renewed; if this is the case, it is worth dismantling the regulator first to check that the fault is not due to its being jammed open with dirt, or similar.
8 Fuel tank - removal and
refitting
2
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
Removal
1 Before the tank can be removed, it must be drained of as much fuel as possible. To avoid the dangers and complications of fuel handling and storage, it is advisable to carry out this operation with the tank almost empty. Any fuel remaining can be drained as follows.
2 Disconnect the battery negative lead. 3 Using a hand pump or syphon inserted
through the filler neck, remove any remaining fuel from the bottom of the tank. Do this in a well ventilated area, not in a garage or over an inspection pit 4 Remove the luggage compartment carpet and the spare wheel. 5 Release the two retaining studs, and remove the trim panel from the side of the fuel tank. 6 Disconnect the wiring connectors from the fuel gauge sender unit. 7 Release the retaining clip, and disconnect the vent pipe from the fuel tank. 8 Bearing in mind the information contained in Section 6 on depressurising the fuel system, release the retaining clips and disconnect the fuel feed and return hoses from the tank; the feed hose is marked with a yellow band, and the return hose is unmarked. 9 Undo the fuel tank strap retaining bolt, then remove the strengthening plate and move the strap to one side. 10 Release the fuel tank filler neck from its grommet, and remove the grommet from the car. 11 Peel back the rubber cover, then disconnect the wiring connector from the fuel pump, and remove the fuel tank from the vehicle.
Refitting
12 Refitting is the reverse sequence to removal, ensuring that all hoses are correctly reconnected and securely fastened so that there can be no risk of fuel leakage.
9 Fuel pump - removal and
refitting
2
Note: Observe the precautions in Section 1 before working on any component in the fuel system.
Removal
1 Remove the fuel tank as described in Section 8. 2 Release the retaining clip, and disconnect the two-way breather valve vent hose from the fuel tank. Unclip the valve and hose assembly from the tank seam, and remove it. 3 Slacken and remove the six fuel pump retaining nuts, then carefully withdraw the pump assembly from the tank, and remove the pump seal.
Refitting
4 Examine the pump seal for signs of damage or deterioration and, if necessary, renew it. 5 Ensure that the pump and tank mating surfaces are clean and dry, and fit the seal onto the fuel tank. 6 Carefully install the pump assembly, then refit the pump retaining nuts and tighten them to the specified torque. 7 Clip the two-way valve and hose assembly back onto the tank seam, then reconnect the vent hose to the tank, securing it in position with its retaining clip.
8 Refit the fuel tank as described in Section 8.
10 Fuel gauge sender unit -
removal and refitting
2
Refer to Part A, Section 8.
11 Unleaded petrol - general
information and usage
Note: The information given in this Chapter is correct at the time of writing. If updated information is thought to be required, check with a Rover dealer. If travelling abroad, consult one of the motoring organisations (or a similar authority) for advice on the fuel available.
All fuel injection models are designed to run on fuel with a minimum octane rating of 95 (RON). All models are equipped with catalytic converters, and therefore must be run on unleaded fuel only. Under no circumstances should leaded fuel be used, as this may damage the catalytic converter.
Super unleaded petrol (97/98 RON) can also be used in all models if wished, though there is no advantage in doing so.
12 Fuel injection system -
testing and adjustment
3
Testing
1 If a fault appears in the fuel injection system, first ensure that all the system wiring connectors are securely connected and free of corrosion. Ensure that the fault is not due to poor maintenance; ie, check that the air cleaner filter element is clean, the spark plugs are in good condition and correctly gapped, the valve clearances are correctly adjusted, the cylinder compression pressures are correct, and that the engine breather hoses are clear and undamaged, referring to Chapters 1 and 2 for further information. 2 If these checks fail to reveal the cause of the problem, the vehicle should be taken to a suitably-equipped Rover dealer for testing. A wiring block connector is incorporated in the engine management circuit, into which a special electronic diagnostic tester can be plugged. The tester will locate the fault quickly and simply, alleviating the need to test all the system components individually, which is a time-consuming operation that also carries a risk of damaging the ECU.
Adjustment
3 Experienced home mechanics with a considerable amount of skill and equipment (including a tachometer and an accurately calibrated exhaust gas analyser) may be able to check the exhaust CO level and the idle speed. However, if these are found to be in need of adjustment, the car must be taken to a suitably-equipped Rover dealer for further testing. Note: There is no provision for the
adjustment or alteration of these settings, except by reprogramming the ECU using Rover diagnostic equipment; if checking the idle speed, remember that it will vary constantly under ECU control.
13 Fuel injection system
components - removal and
refitting
3
Throttle body
Note: Refer to the warning note in Section 1 before proceeding.
Removal
1 Remove the air cleaner assembly, as
described in Section 2. 2 Slacken and remove the bolt and retaining clip securing the fuel pipes to the bulkhead (see illustration). Examine the injector housing fuel pipe feed and return unions for signs of leakage, then wipe them clean. 3 Bearing in mind the information contained in Section 6 on depressurising the fuel system, using an open-ended spanner to hold
Fuel system - fuel injection engines 4B•5
4B
each adapter, unscrew the pipe union nuts, and release the fuel feed and return pipes from the adapters (see illustration). Plug each pipe and adapter, to minimise the loss of fuel and prevent the entry of dirt into the system. 4 Release the wire retaining clips, and disconnect the wiring connectors from the injector housing, the throttle potentiometer and the stepper motor. 5 Slacken the accelerator cable locknuts, and free the outer cable from its mounting bracket. Release the inner cable from the throttle cam. 6 Release the retaining clip(s), and disconnect the breather and purge valve hoses from the front of the throttle body (see
illustration). 7 On models with automatic transmission,
disconnect the governor control rod from the throttle linkage. 8 Slacken and remove the four nuts securing the throttle body to the inlet manifold, then remove the throttle body from the car. Remove the insulating spacer, and examine it for signs of wear or damage, renewing it if necessary. 9 If leakage was detected from the feed and return pipes or their union nuts, check the sealing surfaces of the nuts and adapters, and renew the adapter or the pipe assembly as necessary. If leakage was detected from the adapters, unscrew each through one turn with a spanner, then through two turns by hand; if the adapter is still a tight fit in the housing, the threads are damaged, and the housing and adapters must be renewed as a set. If the
threads are sound, fit new sealing washers to the adapters and refit them, tightening them to their specified torque wrench setting.
Refitting
10 Refitting is the reverse sequence to
removal, noting the following points:
a) Ensure that the mating surfaces of the
throttle body and inlet manifold are clean, then fit the insulating spacer.
b) Tighten the throttle body nuts and fuel
pipe union nuts to their specified torque settings. Note that when tightening the injector housing fuel pipe union nuts, do not use an open-ended spanner to retain the adapters; this will ensure that the adapters are securely tightened in the injector housing.
c) On completion, reconnect and adjust the
accelerator cable as described in Section
4.
Injector housing
Note: Refer to the warning note in Section 1 before proceeding.
Removal
11 Carry out the operations described in
paragraphs 1 to 3. 12 Release the wire retaining clip, and disconnect the wiring connector from the injector housing (see illustration). 13 Remove the four screws securing the injector housing to the throttle body (see illustration), then lift off the injector housing and remove the gasket. 14 If leakage was detected from the fuel feed
and/or return pipes, perform the checks described in paragraph 9.
Refitting
15 Refitting is the reverse sequence to
removal, noting the following points:
a) Ensure that the injector and throttle body
mating surfaces are clean, and fit a new gasket.
b) Apply thread-locking compound (Rover
recommended Loctite Screwlock or Nutlock) to the threads of the injector housing screws, then tighten them to the specified torque.
c) Tighten the fuel pipe union nuts to the
specified torque setting, noting that when tightening the union nuts, do not use an open-ended spanner to retain the adapters; this will ensure that the adapters are securely tightened in the housing.
Fuel injector
Note: As a Rover replacement part, the injector is available only as part of the injector housing. Note, however, that it is a Bosch­manufactured component, and can be obtained separately through Bosch agents. Refer to the warning note in Section 1 before proceeding.
Removal
16 Disconnect the battery negative lead. 17 Remove the air cleaner assembly as
described in Section 2. 18 Slacken and remove the injector connector cap retaining screw, and lift off the connector cap (see illustration). As the screw is slackened, place a clean rag over the cap to catch any fuel spray which may be released. The injector can then be lifted out of the housing.
Refitting
19 Refitting is the reverse sequence to
removal, ensuring that the connector cap makes good contact with the injector pins.
Fuel pressure regulator
20 The fuel pressure regulator is available only as part of the injector housing assembly. Refer to paragraphs 11 to 15 for details on removal and refitting.
4B•6 Fuel system - fuel injection engines
13.2 Undo the retaining bolt (arrowed) and remove the fuel pipe retaining clip
13.3 Retain the adapters with an open-
ended spanner whilst slackening the fuel
pipe union nuts
13.6 Disconnect the breather and purge
valve hoses from the front of the throttle
body assembly
13.12 Disconnecting the injector housing wiring connector
13.13 Injector housing retaining screws (arrowed)
Stepper motor
Removal
21 Remove the injector housing as described
in paragraphs 11 to 14. 22 Release the retaining clip, and disconnect the stepper motor wiring connector. 23 Remove the four stepper motor retaining screws, and remove the stepper motor assembly from the throttle body. Do not attempt to dismantle the assembly.
Refitting
24 Refitting is the reverse sequence to
removal, ensuring that the throttle body and motor mating surfaces are clean. On completion, adjust the accelerator cable as described in Section 4, to ensure that the stepper motor is correctly indexed.
Throttle potentiometer
Removal
25 Although not strictly necessary, access is
greatly improved if the air cleaner assembly is first removed, as described in Section 2.
26 Disconnect the battery negative lead. 27 Release the wire retaining clip, and
disconnect the potentiometer wiring connector.
28 Remove the two screws, and remove the potentiometer from the throttle body, noting how its tongue engages with the throttle disc spindle lever. Withdraw the spacer if required.
Refitting
29 Refitting is the reverse sequence to
removal, noting the following points:
a) Carefully clean the mating surfaces of the
throttle body, the spacer and the potentiometer, then refit the spacer.
b) Refit the potentiometer so that its tongue
engages FORWARD of (ie “inside”) the throttle disc spindle lever, then rotate the throttle cam to check the action of the lever and tongue.
c) Securely tighten the potentiometer
screws, then recheck the potentiometer operation before reconnecting the wiring connector.
Engine management ECU
Removal
30 Disconnect the battery negative lead, and
undo the two bolts securing the ECU mounting bracket to the right-hand wing valance (see illustration). 31 Withdraw the ECU from the engine
compartment, disconnecting its wiring connectors and the manifold absolute pressure sensor vacuum hose as they become accessible (see illustration). 32 If necessary, undo the three screws and separate the ECU from its mounting bracket.
Refitting
33 Refitting is the reverse sequence to
removal, ensuring that the wiring connectors and vacuum hose are securely reconnected. Due to the nature of the ECU, if a new or different ECU has been fitted, it may take a short while for full idle control to be restored.
Manifold absolute pressure (MAP) sensor
34 This is part of the ECU, and is removed and refitted as described in the previous sub­section. 35 The sensor’s vacuum hose runs from the inlet manifold to the ECU via a fuel (vapour) trap mounted on the engine compartment bulkhead. 36 To remove the fuel trap, first remove the air cleaner assembly as described in Section 2. Release the fuel trap from its retaining clip, then disconnect the two vacuum hoses, noting their correct fitted positions, and remove it from the engine compartment (see
illustration). 37 On refitting, ensure that the vacuum
hoses are reconnected to their original unions; the hoses are colour-coded to ensure correct reconnection.
Inlet air temperature sensor
Removal
38 Disconnect the battery negative lead. 39 Remove the air cleaner assembly as
described in Section 2. 40 Unscrew the sensor, and remove it from the base of the air cleaner housing (see illustration).
Fuel system - fuel injection engines 4B•7
4B
13.31 . . . then withdraw the ECU and
disconnect the vacuum hose and wiring
connectors
13.36 Removing the manifold absolute pressure (MAP) sensor fuel
13.18 Injector cap retaining screw “A” and fuel pressure regulator retaining screws “B”
13.30 Undo the ECU mounting bracket-to-wing valance retaining bolts (arrowed) . . .
Refitting
41 Refitting is the reverse sequence to
removal. Tighten the sensor to the specified torque wrench setting.
Coolant temperature sensor ­removal and refitting
Removal
42 The coolant temperature sensor is fitted
to the underside of the inlet manifold, and access to the sensor is strictly limited. Therefore, to remove the sensor, it will first be necessary to remove the inlet manifold as described in Section 15. The sensor can be unscrewed and removed from the manifold.
Refitting
43 Wipe clean the threads of the switch and
inlet manifold. If a sealing washer is fitted, apply a smear of sealant to the switch threads. 44 Refit the switch to the manifold, and tighten it securely. Refit the manifold as described in Section 15.
Accelerator pedal switch
Removal
45 Working from inside the car, release the
heater duct from underneath the driver’s side of the facia panel, and position it clear of the accelerator pedal. 46 Using a suitable pair of pliers, unhook the accelerator pedal return spring from the pedal. 47 Release the switch wiring connector from its retaining clip, and disconnect it (see
illustration). 48 Slacken and remove the accelerator pedal
switch mounting bracket retaining bolt, and remove the switch and bracket assembly from the car (see illustration). 49 Prise off the C-clip, and remove the switch from the mounting bracket, noting the wave washer which is fitted between the switch and bracket.
Refitting
50 Refitting is the reverse sequence to
removal.
Fuel cut-off inertia switch
51 The fuel cut-off inertia switch is mounted onto the left-hand side of the engine compartment bulkhead (see illustration). If the switch has tripped, it can be reset by pressing in the button situated at the top of the switch.
Removal
52 Slacken and remove the two screws
securing the cut-off switch to the bulkhead, then disconnect the wiring connector and remove the switch.
Refitting
53 Reconnect the wiring connector, then refit
the switch to the bulkhead and tighten its retaining screws securely. Reset the switch by depressing the button on the top of the switch.
Relay module
54 The relay module contains the four main relays which control the engine management system; the starter relay, the fuel pump relay,
4B•8 Fuel system - fuel injection engines
13.48 . . . then undo the retaining bolt (arrowed) and remove the accelerator pedal switch assembly from the car
13.51 Fuel cut-off inertia switch (arrowed) is mounted onto the left-hand side of the engine compartment bulkhead
13.40 Removing the intake air temperature sensor from the air cleaner housing
13.47 Disconnect the wiring connector . . .
the main relay and the manifold PTC heater relay. If a fault develops in any one of the system relays, the complete relay module must be renewed; it is not possible to renew the separate relays individually.
Removal
55 Slide the relay off its mounting bracket in
the right-hand rear corner of the engine compartment, then disconnect its wiring connectors and remove it from the car (see
illustration).
Refitting
56 Refitting is the reverse sequence to
removal.
14 Inlet manifold PTC heater -
general information and component renewal
3
General information
1 The system incorporates the manifold PTC (Positive Temperature Coefficient) heater, the relay and the coolant temperature sensor. 2 When the ignition is switched on and the engine is cold (coolant below 50ºC), the relay­energising current is supplied by the engine management ECU, which then closes the relay contacts and allows current to flow from the battery to the heater. This ensures that the inlet manifold is warm enough, even before the effect of the coolant heating becomes apparent, to prevent fuel droplets condensing in the manifold, thus improving driveability and reducing exhaust emissions when the engine is cold. 3 As soon as the engine warms up to temperatures above 50ºC, the ECU switches off the supply current, and the relay cuts off the power supply to the manifold heater. 4 If the engine suddenly develops flat spots when cold, the system may be faulty.
Component renewal
PTC heater
5 The PTC heater is fitted to the underside of
the inlet manifold, and access to the heater is strictly limited. Therefore, to remove the heater, it will first be necessary to remove the inlet manifold as described in Section 15. With the manifold on the bench, using circlip pliers, remove the circlip and withdraw the heater. Inspect the rubber sealing ring for signs of damage or deterioration, and renew if necessary. 6 On refitting, ensure that the heater locating projection is correctly engaged in the manifold recess, then secure the switch in position with its circlip. Refit the manifold to the car as described in Section 15.
PTC heater relay
7 The manifold PTC heater relay is an integral
part of the relay module, and can be removed and refitted as described in Section 13.
15 Inlet manifold - removal and
refitting
3
Removal
1 Disconnect the battery negative lead. 2 Remove the bonnet as described in
Chapter 11. 3 Remove the air cleaner assembly as described in Section 2. 4 Drain the cooling system as described in Chapter 1. 5 Carry out the operations described in paragraphs 2 to 7 of Section 13. 6 Undo the union bolt securing the brake servo vacuum hose to the manifold, and recover the hose union sealing washers (see
illustration). 7 Slacken the two hose clips, and disconnect
the two coolant hoses from the left-hand side of the manifold. 8 Disconnect the two vacuum hoses from the rear of the inlet manifold, noting their correct fitted positions; the hoses are colour coded for identification purposes. 9 Slacken and remove the four nuts securing the inlet manifold to the cylinder head, then remove the manifold from the engine, disconnecting the manifold PTC heater and coolant temperature sensor wiring connectors as they become accessible. Remove the two rings from the inlet manifold bore.
Refitting
10 Refitting is the reverse sequence to removal, noting the following points:
a) Although not strictly necessary, it is also
recommended that the exhaust manifold is removed, as described in Part C of this Chapter, so that the manifold gasket can be renewed before the inlet manifold is refitted.
b) If leakage was detected from the fuel feed
and/or return pipes, perform the checks described in Section 13, paragraph 9.
c) Ensure that the manifold and gasket faces
are clean, and that the two locating rings are in position in the manifold bores before refitting the manifold.
d) Tighten the manifold retaining nuts to the
specified torque setting.
e) Ensure that all relevant hoses are
reconnected to their original positions, and are securely held (where necessary) by the retaining clips.
f) Renew the vacuum servo unit vacuum
hose banjo union sealing washers, and tighten the union bolt to the specified torque.
g) Prior to refitting the air cleaner assembly,
adjust the accelerator cable as described in Section 4.
h) On completion, refill the cooling system
as described in Chapter 1.
Fuel system - fuel injection engines 4B•9
4B
13.55 Relay module is situated on the right-hand side of the engine compartment
15.6 Inlet manifold brake servo unit vacuum hose union bolt (arrowed)
4C
Chapter 4 Part C:
Exhaust and emission control systems
Torque wrench settings Nm lbf ft
Thermostatic vacuum valve - 1992-on models . . . . . . . . . . . . . . . . . . . 10 7
Manifold retaining nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 16
Lambda sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 41
Fuel tank breather two-way valve nuts . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6
Air pump drivebelt check and renewal . . . . . . . . . . . . . .See Chapter 1
Catalytic converter - general information and precautions . . . . . . . . 9
Crankcase emission control system - checking and component
renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Emission control system check . . . . . . . . . . . . . . . . . . . .See Chapter 1
Evaporative emission control system - checking and component
renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Exhaust emission control system (models with catalytic converter) -
checking and component renewal . . . . . . . . . . . . . . . . . . . . . . . . . 8
Exhaust emission control system (models without catalytic converter) -
checking and component renewal . . . . . . . . . . . . . . . . . . . . . . . . . 7
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Exhaust system (models with catalytic converter) - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Exhaust system (models without catalytic converter) - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Underbonnet check for fluid leaks and hose condition . .See Chapter 1
4C•1
Specifications
Contents
Easy, suitable for
novice with little experience
Fairly easy, suitable for beginner with some experience
Fairly difficult,
suitable for competent DIY mechanic
Difficult, suitable for experienced DIY mechanic
Very difficult,
suitable for expert DIY or professional
Degrees of difficulty
5
4
3
2
1
1 General information
Exhaust system
The exhaust system fitted to all Mini models covered by this manual, except Cooper S, consists of an exhaust manifold and a tubular steel exhaust system in either single or multiple sections. A single silencer is fitted to the rear section of early models; later versions incorporate an additional intermediate silencer or catalytic converter. The system fitted to Cooper S models comprises a three branch manifold, a front pipe and separate tailpipe incorporating a silencer. Certain versions have a second silencer located beneath the floor pan.
On all models the exhaust system is flexibly attached to the car by two rubber mountings on the rear subframe and a bracket at the base of the transmission.
Emission control systems
Certain early models and all later models covered by this manual have various features
built into the fuel and exhaust systems to help minimise harmful emissions. These features fall broadly into three categories; crankcase emission control, evaporative emission control, and exhaust emission control. The main features of these systems are as follows.
Crankcase emission control
To reduce the emissions of unburned hydrocarbons from the crankcase into the atmosphere, a positive crankcase ventilation system is used whereby the engine is sealed and the blow-by gasses and oil vapour are drawn from inside the crankcase, through an oil separator, into the inlet tract to be burned by the engine during normal combustion.
Under conditions of high manifold depression (idling, deceleration) the gasses will be sucked positively out of the crankcase. Under conditions of low manifold depression (acceleration, full-throttle running) the gasses are forced out of the crankcase by the (relatively) higher crankcase pressure; if the engine is worn, the raised crankcase pressure (due to increased blow-by) will cause some of the flow to return under all manifold conditions.
Evaporative emission control
The evaporative emission control system is used to minimise the escape of unburned hydrocarbons into the atmosphere.
The fuel tank filler cap is sealed, and a charcoal canister is mounted underneath the left-hand wheel arch to collect the petrol vapours generated in the tank, and on some models in the carburettor float chamber, when the car is parked. It stores them until they can be cleared from the canister into the inlet tract, to be burned by the engine during normal combustion.
On early carburettor models, the vapours were drawn into the inlet tract whenever the engine was running. On later catalytic converter equipped carburettor models, a thermostatic vacuum valve screwed into the front of the thermostat housing controls the flow of vapour from the canister to the engine. To ensure that the engine runs correctly when it is cold, and to protect the catalytic converter from the effects of an over-rich mixture, the thermostatic vacuum valve does not open until the engine has warmed up to approximately 70ºC. The valve then allows inlet manifold vacuum to act upon the purge valve vacuum diaphragm fitted to the top of the charcoal canister, which in turn opens the
4C•2 Exhaust and emission control systems
2.2 Typical exhaust system support brackets and mountings
canister and allows the stored vapour into the inlet tract.
On fuel injection models, the engine management ECU controls the flow of vapour from the canister to the engine, via an electrically-operated purge control valve.
The purge control valve is not opened by the ECU until the engine has warmed up to above 70ºC, the engine speed exceeds 1500 rpm and manifold absolute pressure is below 30 kPa; the control valve solenoid is then modulated on and off to allow the stored vapour to pass into the inlet tract.
Exhaust emission control ­carburettor models without catalytic converter
The basis of this system, used on certain early models, is an air pump which supplies air under pressure to the cylinder head exhaust port of each cylinder, via an air injection manifold. A check valve is incorporated in the air delivery pipe to prevent a blow-back of exhaust gases from reaching the pump. Air from the pump is also supplied to the inlet manifold via a gulp valve to weaken the rich fuel/air mixture in the manifold during engine deceleration and overrun.
The air pump is of the rotary vane type and is mounted at the front of the cylinder head. Drive to the pump is by a V-belt from the water pump pulley. Air enters the pump through an extraction filter on early models, or through radial air inlets around the pulley on later versions. At high engine speeds, excess air is discharged to atmosphere through a relief valve.
A diverter valve is incorporated in the air delivery pipe between the air pump and check valve. The valve is operated by a cable on early models, or activated by a vacuum switch on later types, whenever the choke control is pulled out. During choke operation, air from the pump is cut off and diverted to atmosphere.
When the throttle is closed during deceleration or overrun, a rich fuel/air mixture is created in the inlet manifold. The gulp valve fitted between the air pump and manifold is activated by the depression also created in the manifold during these conditions, and opens to admit air from the air pump. The mixture is thus weakened preventing excessive exhaust emissions when the throttle is reopened. A restrictor is also fitted in the air feed to the gulp valve and prevents surging when the valve is in operation.
Exhaust emission control ­carburettor models with catalytic converter
From approximately 1990 onwards certain models were fitted with an unregulated or “open-loop” catalytic converter to minimise exhaust pollution. The converter consists of an element (or “substrate”) of ceramic honeycomb coated with a combination of precious metals (platinum and rhodium) in such a way as to produce a vast surface area over which the exhaust gasses must flow; the
assembly being mounted in a stainless-steel box in the vehicle’s exhaust system. The precious metals act as catalysts to speed up the reaction between the pollutants and the oxygen in the car’s exhaust gasses. HC and
CO being oxidised to form H
2
O and CO2.
Exhaust emission control - fuel injection models
All fuel-injection models are equipped with a catalytic converter in the exhaust system. The system, unlike that fitted to carburettor models, is a “closed-loop” system. The Lambda sensor in the exhaust manifold provides the engine management ECU with constant feedback on exhaust gas content, which enables the ECU to adjust the inlet fuel/air mixture to keep the converter operating at maximum efficiency.
The Lambda sensor has a built-in heating element, controlled by the ECU through the Lambda sensor relay to quickly bring the sensor’s tip to an efficient operating temperature. The sensor’s top is sensitive to oxygen, and sends the ECU a varying voltage
depending on the amount of oxygen in the exhaust gases; if the inlet air/fuel mixture is
too rich, the exhaust gases are low in oxygen, so the sensor sends a low-voltage signal; the voltage rises as the mixture weakens and the amount of oxygen in the exhaust gases rises. Peak conversion efficiency of all major pollutants occurs if the inlet air/fuel mixture is maintained at the chemically-correct ratio for the complete combustion of petrol - 14.7 parts (by weight) of air to 1 part of fuel (the “stoichiometric” ratio). The sensor output voltage alters in a large step at this point, the ECU using the signal change as a reference point, correcting the inlet fuel/air mixture accordingly by altering the fuel injector pulse width.
2 Exhaust system (models
without catalytic converter) -
removal and refitting
1
All models except Cooper S
Removal
1 Working in the engine compartment,
Exhaust and emission control systems 4C•3
4C
3.2 Exhaust front pipe fitted to models with catalytic converter
1 Catalytic converter flange nuts 2 Gas sampling pipe union nut 3 Gas sampling pipe mounting bolt
4 Front pipe mounting nut 5 Front pipe-to-manifold clamp and
bolts
Position a jack under the exhaust front pipe and raise it just sufficiently to hold the
bellmouth tightly against the manifold flange. This will ensure that the joint is properly seated as the clamp is fitted.
Apply liberal amounts of releasing oil to the exhaust tailpipe-to-front pipe joint if it is reluctant to come free,
and allow it time to soak in.
remove the air cleaner (see Part A of this Chapter) and detach the throttle return spring from the bracket on the exhaust manifold clamp. 2 Undo and remove the nuts and bolts and withdraw the manifold clamp (see
illustration). 3 Position the car over an inspection pit, or
alternatively jack it up and support it on axle stands (see “Jacking and vehicle support”). 4 From underneath the car, undo and remove the nut and bolt securing the exhaust front pipe to the transmission or transmission bracket. 5 Now undo and remove the nuts and spring washers securing the exhaust intermediate and rear mounting brackets to the rubber blocks on the rear subframe. Slide the brackets off the studs on the rubber blocks and lower the complete system to the ground. 6 Carefully inspect the rubber mounting blocks, the exhaust system brackets and clamps for signs of deterioration, corrosion or damage and renew as necessary.
Refitting
7 To refit the exhaust system, place it in
position under the car and locate the brackets onto the rubber mounting blocks at the rear. Refit the nuts and spring washers but do not tighten at this stage. 8 Before positioning the bellmouth of the front pipe over the manifold flange, smear its mating surface with sealing paste. Doing this will obviate any risk of leakage. With the help of an assistant, locate the bellmouth squarely over the flange on the manifold. Hold the system in this position and refit the manifold clamp. Ensure that the pipe is square and that the clamp is seated properly over the pipe and manifold flanges otherwise leaks will occur at this joint. 9 Now fully tighten the manifold clamp securing bolts and refit the throttle return spring. 10 Check that the exhaust system is clear of the subframe and floor pan over its entire length and that it is not in tension. Now fully tighten the rear mountings. 11 Lower the car to the ground, refit the air cleaner, start the engine and check for leaks.
Cooper S models
Removal
12 Position the car over an inspection pit, or
alternatively jack it up and support it on axle stands (see “Jacking and vehicle support”). 13 If the rear silencer and tailpipe only are to be removed, slacken the exhaust clamp securing the rear silencer to the front pipe and then remove the retaining clip securing the tailpipe to the rear mounting. Twist the rear silencer back and forth to separate the joint and
then withdraw the tailpipe from under the car. 14 To remove the complete system, slacken the front pipe to exhaust manifold clamp, and undo and remove the bolts securing the rear mountings to the subframe. Twist the complete system back and forth to free the joint and lower it to the ground.
Refitting
15 In all cases, refitting is the reverse of
removal.
3 Exhaust system (models
with catalytic converter) -
removal and refitting
1
Tailpipe and silencer
Removal
1 Position the car over an inspection pit, or
alternatively jack it up and support it on axle stands (see “Jacking and vehicle support”). 2 Slacken and remove the two nuts securing the tailpipe flange to the catalytic converter studs (see illustration). 3 Either slacken and remove the nuts and bolts securing the tailpipe and silencer to its mounting brackets, or release it from its mounting rubbers (as applicable), then withdraw the assembly from underneath the car and recover the flange gasket.
Refitting
4 Refitting is the reverse sequence to
removal, ensuring that the flange mating surfaces are clean and free of corrosion, and using a new gasket.
Catalytic converter
Removal
5 Remove the tailpipe and silencer assembly
as described above. 6 Unscrew the two nuts securing the catalytic converter to the front pipe, then withdraw the catalytic converter from underneath the car and recover the flange gasket.
Refitting
7 Refitting is the reverse sequence to
removal, ensuring that the flange mating surfaces are clean and free of corrosion and using new gaskets.
Front pipe
Removal
8 On carburettor models, remove the air
cleaner assembly (see Part A of this Chapter). 9 Position the car over an inspection pit, or alternatively jack it up and support it on axle stands (see “Jacking and vehicle support”). 10 Slacken and remove the two nuts securing the catalytic converter to the front
pipe. Unscrew the nut and bolt securing the front pipe to the bracket on the transmission. 11 On Cooper models, undo the gas sampling pipe mounting bolts, then slacken its union nut and remove the pipe from the side of the exhaust front pipe. 12 On all carburettor models, unbolt the exhaust front pipe-to-manifold clamp(s), then remove the front pipe from underneath the car, and recover the flange gasket from the catalytic converter. 13 On fuel injection models, undo the three nuts securing the front pipe to the exhaust manifold, then release the pipe from the manifold and catalytic converter studs. Remove the front pipe from underneath the car, and recover the flange gaskets.
Refitting
14 Refitting is the reverse sequence to
removal, ensuring that the mating surfaces of the exhaust system are clean and free from corrosion. Fit a new gasket to the catalytic converter flange, and apply a smear of sealing paste to the front pipe-to-manifold joint, to alleviate any risk of leakage.
4 Exhaust manifold - removal
and refitting
3
Carburettor models except Cooper S
1 The exhaust manifold fitted to all carburettor models except Cooper S is removed as an assembly with the inlet manifold. Full details on this procedure will be found in Part A of this Chapter.
Cooper S carburettor models
Removal
2 Remove the carburettors and inlet manifold
as described in Part A of this Chapter. 3 Remove the complete exhaust system as described in Section 2 of this Part. 4 Undo and remove the nuts and flat washers securing the manifold to the cylinder head studs. Now ease the manifold off the studs and carefully manipulate it out of the engine compartment. 5 Before removing the LCB (long centre branch) exhaust manifold, refer to Chapter 8 and detach the right-hand driveshaft at the inboard end. 6 Refer to Chapter 10 and remove the right­hand front roadwheel, disconnect the steering tie-rod, the swivel hub at its upper and lower points, and partially withdraw the hub and driveshaft. Do not allow the assembly to hang from the brake hose. 7 Turn the differential driving flange so that it is upright. Release the exhaust manifold from the cylinder head, manoeuvre it to the right to clear the subframe and transmission casing before easing it upwards.
Refitting
4C•4 Exhaust and emission control systems
Position a jack under the exhaust front pipe and raise it just sufficiently to hold the
bellmouth tightly against the manifold flange. This will ensure that the joint is properly seated as the clamp is fitted.
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