Bentley R Type Handbook

Handbook

t'rtr-

-

Ine

Bentley R

Type

Number

XIV

Reprinted

IWSW Pmduet

Support

(Graphics)

Ltd.,3l7$nt

HE

information

contained

in this

book has

been

arranged

to

facilitate

reference,

by

condensing

all

essential

driving

and

upkeep instructions

in

the

first two

chapters.

Numerous

references to

other

parts

are

provided, whereby

any

particular

instruction

may

be amplified

if required.

Subsequent

chapters

include

explanations

of

the

working

of the

various

units or

components

of

the

chassis,

and include detailed

directions

for lubrication

and

maintenance.

Owners

and drivers should,

therefore,

familiarise

themselves

with the

first

two chapters

in order to

operate

the

car

successfully,

referring to

the remainder

of

the

book at leisure,

or if

necessarv.

A

set

of

special spanners

and tools

is

supplied

with

the

chassis.

It is

most desirable

that

these

should

be

used

when

effecting

any adjustment,

as otherwise

vital

parts

may be seriously

damaged.

It

is

strongl,y

recovwneniled

that

this

booh be

careful'ly

studied,

and

the

instructions

faithfully

followed,

to ensure

the

greatest

satisfaction.

CONTENTS

Pecp

Cneprpn

I.-SrenTING

THE ENGINE

AND

Dnrvrwc

rnr Can 2r

Starting

the Engine-use

of

Starting

Handle-Automatic

Gear

changing-Tow

starting-Fuel

Feed-l.-uel

Gaug_e-chassis

Lubricaiion-Controllable-

Shock

Dampers-Battery

Charging-

Lighting

control and

switch-Accessories-Engine

Thermostat

ani Thlermometer-Coolant

Level

in

Radiator-Frost-Fitting

of

Snow

Chains.

Cseprnn

II.-PnnIoDrc

LurnrcerloN

AND

ATTENTIoN

27

Lubricants

Recommended-Capacities-Points

for

Regular

Atten-

tion according

to Use of

Car-Adjusting

Valve

Rocker

Clearances.

Cneprrn

III.-CnNTRALTsED

CHASSIS

LUBRIcATIoN

General-Foot-operated

Oil

Pump-Drip

Plugs.

35

Cneprnn

IV.-ENGINE

LusntcerloN

Svs:rcna

39

Filling

the System-Oil

Pump-Oit

Filter-Crankshaft

and

ConnJcting

Rods-Relief

Valves-Valve

Rockers,

Push

Rods

and

Tappets-tamshaft-Oil

Sump-Oil

Level

Indicator-Oil

Pressure.

Cneprrn V.-Tsn

FuBr

Svsrnu

The

Fuel

System-Fuel

Pumps-Faulty

Operation

of

Pumps-Fuel

Tank-Fuei

Filters-Fuel

Gauge-The

Carburetters

(Action)-

Automatic

Air

Valve-Throttle

eontrol-Automatic

Choke

Control

-Float

Feed

Mechanisms-Further

Dismantling

of

carburetter-

Adjustment

of

controls-setting

of

Idling-

Adjustments-Air

Cle-aner and

Silencer

(Standard

Type)-Air

Cleaner

and Silencer

(Oil

Bath Ttpe).

45

57

Cneprnn.VI.-Tur

BnexrNG SYsTEM

General

Description-Possible

Variations-Adjustments-A.djust-

ment of

Harid

Brake-Adiustment

of

Servo-Lubrication-

Bleeding

the Hydraulic System-Hydraulic

Master

Cylinder.

CnaprnR

VII.-GrARBox,

Pnopnr,ER

SHAFT

AND

REAn

AxrB...

The

Gearbox-Universal

Joints-

Rear Axle'

Cneprnn

VIII.-STEERIN6,

SnOcr

Deupnns,

Rortn

Srntucs,

WsBBr,s AND

TYREs

67

Steering

Box

and

Column-steering-Front

Suspension-lilarning,

Front

-suspension
Springs-steering

Arms-and-Joitlt:Front

Stabiliser-lRear

Hydiaulic Shock

pampqlg-Rear

Road

Spjings-

Wheels-Wheel Discs-Lubrication

of-

Wheel

Bearings-Tyres-

The

Jacking

System-Wheel

Changing-Fitting-

and

Removing

Tyre{-Inflatjon

of

Tvres-Balaucing

Road

Wheels.

6s

Contents-continucd.

Pecp

CgeprBn

IX.-EIIGINE

Coor,rxc

Sysrnu

...

...

..,

...

79

coolant-coolant

Pump

and Fan-Fan

Belt

Adjustment-ovor-

heating-Engine

Therniostat-Radiator

Mounting-Frost and

Anti

freeze Mixtures-Car

Heater.

Cneprrn

X.-Tlln

Er,BcrnrcAl-

SYsTEM

...

o..

85

.General-Dynamo-Fuse

Box-Output

Re_gulator and

cut-out-

Switchbox

--

Ammeter

-

Battery

-

First

Charge

-

Topping-Up-

Specific

Gravity

of

_Electrolyte-charging-_

charging

pattery

from

oirtside

sourc6-Maintenance-Ignition-Ignition

coil-Ignition

Timing-Firing

order

of cylinders-spark-ing

__Plugs- ltarter

Motor--starter

Motor

Switch-Micro-switch-use

of

starter

.

Motor-Electric

Fuel

Pumps

and

Gauge-Electric

Horns-De-

misting

Equipment-Electrical

Fault

-Location-Recommended

Lamp

-eulUi-Headlamps-Replacing
a.Headlamp

g"t-

4Igning

the

i{eadlamps-The

Si-de

Lamps-Radio-To

set

up

The Tuning

Push

Buttons.

Cneprrn

XI.-Tss

Bonv

AND

CoAcHwoRK

...

ro5

General-Windscreen

Washing-Washing

and

Polishing-Doors-

Seat

Slides-Upholstery

and

earpets-sliding

Roof-Luggage

and

Spare

Wheel Compartrnents-Tools.

CneprBn

XII.-SIoRAcE

AND REcoMMISsIoNINc

oF CARs

III

Cneprpn

XIII.-BENTLEY

Scnoor,

or

INSTRUcTToN

II3

INnnx.

INDBX

Pecn

"'30,

90
92

30'

33,

53,

...24,

gr

"'30'

90

Acid in

Battery,

Inspection

of

Adjustment

of Contact Breakers

Adjustment

of Carburetter

Adjustment

of

Fan

Belt

Adjustment

of

Brakes

Adjustment

o{ Hand

Brake...

Adjustment

of Ignition

Plugs

3r,

95
6r

Adjustment

of Servo

Motor

Adjustment

of Valve

Rockers

Aerial,

Operation

of ...

Air

Silencer

and Cleaner

Aligning

the

Headlamps

Ammeter

gg

Anti-Freeze

Mixtures...

...2g, Er

Automatic

Air

Valve,

Carburetter

...3o,

49

Automatic

Choke,

Carburetter

5r

34,

65

2E

92

Axle,

Lubrication

of

Rear

28,

3t,

Axle,

Oil Capacity

of Rea,r

Battery,

Care of

Battery,

Charging

Battery,Jopping

up...

Belt,

Adjustment

of

Fan

Body, Washing

and Polishing

Brakes,

Adjustment

of

Brake,

Adjustment

of Hand

Brushes,

Dynamo

Brushos,

Motor

...33,

g6

52
8o

59

6o

32

r04

54

t02

8o

ro7

30, 59

6o

96

8

Tue

'R'

TypB

BBNrrny.

Camshaft

Carburetter,

Action

of

Carburetter,

Adjustment

Carburetter,

Automatic

Air

Valve...

Carbnretter,

Float

Feed Mechanism

Carburetter,

Needle Valve

Centralised

Chassis

Lubrication

Chains

on Road

Wheels

Changing

Gear

.Changing

a

Wheel

Chassis,

Leading

Particulars

of

Chassis

Lubrication,

Centralised

Coil,

Ignition

Cold

Weather,

Water

in

Cooling

Condenser

of

Contact

Breaker

System

,,.26,

Connecting

Rcids

Contact

Bieaker

Control

Mechanism,

Lubrication

of

Coolant

Level

in

Radiator

...

..i

...25,

Coolant

Mixture

Coolant

Temperature
Crankshaft
Cut-out,

Automatic

Cylinders,

Firing

Order

of

Dampers,

Hydraulic

Shock

Pecn

42
48

52

30,

49
52
5o
35

z6

22

73

r7

35

93

8r

92

4r

92

3r
79

8r
8r

4r
87

95

Dampers,

Governor

for

Hydraulic

Shock

De-froster

arrd

De-mister,

Operating

Distributor,

fgnition

Doors

24,

32,

68, 69

7o
97
92

r07

3I

26,

8z

37

33,

86

86
86
87
85

48, 97

97
85

33,

Draining

Engine

Draining

Cooling

Crankcase

System

Drip

Plugs
Dynamo
Dynamo

Erushes

Dynamo

Connections

Dynamo

Output

Regulator

Earth

Connection

of Batterv

Electric

Fuel Gauge

Electric

Horns

Electric

Lighting,

Starting

and

Ignition

System

23'

INoBx.

Electrical

Fault

Location

Electrolyte,

Inspection

of

Engine

Cooling

System, Capacity

...

Engine Lubrication

System...

Engine,

Quantity

of Oil

in...

.;.

Engine,

Starting

the

Fan,

Engine

Cooling...

Fan

Belt

Adjustment ...

Filler Plug,

Gearbox

Filling

Rear

Axle

Casing

Pecs

g8

30,

90
z8

39
zB

2T

8o
8o

28,

30'34'
3r, 34,

64
65
40

47
95

52
8r

46
45
97

e7
47
47

87

87
98

87

87
63
27
z8

22

Filter,

Engine

Oil

...

30,

Filter,

Cleaning

Fuel

Firing

Order of

Cylinders

Float

Feed Mechanism,

Carburetter

Frost, Precautions

during

...25,

Fuel,

Failure

of

Supply

of

Fuel

Feed

System

...23,

Fuel Gauge
Fuel

Pumps
Fuel Filters
Fuel

Tank

Fuse

Box

Fuse Wire

23,

48,

Fuses,

Failure

of
Fuses, Replacing
Fuses,

Spare

Gearbox

27,

3c

,

34,

Gearbox,

Oil for

Gearbox,

Oil

Capacity

of

Gqar

Changing

Glycol

in

Cooling

System

...25,

Governor

Controlling

Hydraulic

Shock

Dampers

Greases,

Recommended
HeadlEmps
Headlamps,

Alignment

Headlamps,

Replacing

Bulb

Heater,

Car

Iforns,

Electric

I{ubs,

Wheel

79
7r

27

roo

t02

roo

8z
97
7r

6r

Hvdraulic

Brakes

Bleedin

IO

Tnn

'R'

TvpB Brurrny.

Hydraulic Shock Dam
Hydraulic Master Cyli

pers ...

24,

32,

nder ...

assrs

...27,

39

27,

30,

63

Prcp

68,

69

33,

62
92

27

34,

65

72

r09

99

Ignition,

Battery

Ignition Coil

93

Ignition

Plugs...

...

3r,

95

Ignition

Sv-itch

Ignition,

Timing

zt,

24,8g

Instruction

Class,

Bentley

Jack,

Portable

Wheel

'Joints,

Universal

...32,

64

Lamp

Bulbs,

Recommended

99

Lamps,

Head ...

roo

Lighting

Control

...24,

89

Lubricating

Oils and Greases

Recommended

27

Lubrication,

Centralised Ch

Lubrication,

Engine ...

Lubrication,

Gearbox

Lubrication,

Periodic

Lubrication,

Rear

Axle

35

28,

3T,

Lubrication,

Wheel

Bearings

Luggage

and Spare Wbeel ...

Missing

Fire

Motor,

Servo

6r

Motor,

Starter

...32,

95

Oil in

Engine,

Quantity

of ...

z8

Oil in

Gearbox and Back

Axle

z8

Oil Level Indicator,

Engine...

Oil Pressure

Oil

Relief

Valve

Oil

Relief Valve, Dismantling

Oil

Pump, Chassis

Oil

System,

Engine

Oils Recommended

for Bentley

Cars

Output

Regulator,

Dynamo...

Overheating

Pivots,

Steering

Plugs,

Standard

Settings lor

Propeller

Shaft Sliding

Joint

93

I13

72

43
43
4r
4r

37

39
27

87
8o

69

"'3r'

95

"'?2

64

IunBx.

IT

Pump,

Engine

Oil

Pumps,

Fuel

Pump,

Coolant

Radiator,

Draining

Radiator

Mounting

...

Radiator

Thermostat

Radiator,

Coolant

Level

in

"'

z5' 8t

Radio
Rear

Axle,

Quantity

of Oil

Replacing

a

Headlamp

Bulb

Road

Springs,

Lubrication

of

Road

Wheels,

Balancing

Rocker

Shaft ...

Rockers,

Valve

Seat

Slides

...

Service

Facilities

Servo

Motor,

Action

of

Servo Motor,

Adjustment

of

Slow Running..
Sliding Roof
Snow,

Use

of Chains

for Driving

on

Spare

Wheel

Compartment

...

Spark

Gaps,

Standard

Spring

Shackles,

Lubrication

of

Springs,

Road

Stabiliser,

Front

Starter

Motor

...

Starter Motor

Bearings

Starter

Motor

Brushes

Starter

Motor

Connections

...

Starter

Motor,

Failure of

Operation

of

Starter Motor

Lubrication

Starter Motor

Switch

Starter Motor,

Use

of

Starting,

Control Settings

{or

25'

Pear

40

46,

97
8o

26,

8z
8r

29,

79

r03

zB

IOO

7r

7s

42
42

ro8

r6

57
6r

I02

52

r09

z6

r09

3I,

95

36,

7r
7r

6g

32,

95
95

95
g6

q8

32,

96
96

g6

Shock

Dampers,

Hydraulic

...

24,

32,68,69

Side

Lamps

Starting

the

Engine

Steering

Box,

Oiling

Steering

Joints

29,

3t,

2l
2l

67

6g

t2

Tup

'R'

Typa

BBNrrBv.

Steering

Pivots

Storage

of Car

Pecp

6g

III

37
68

Strainer,

Chassis

Oil Pump

Suspension,

Independent

Front

Switchbox

89
8q

96
8r

8r
8r

Switch,

Ignition

2T,

24,

Switch,

Starter

Motor

Temperature

of

Coolant

Thermometer,

Coolant

Temperature

Thermostat,

Engine

Throttle

Control
Tools
Tow

Starting

..
Tyre Pressures
Tyres,

Sizes of

Tyres,

Removal

Upholstery

and

Carpets

Universal

Joints

Valves,

Oil Relief

Valve

Rockers...

Valve

Rocker

Adjustment

Valve

Tappets...

Wheels,

Balancing

Road

Wheel,

Changing

a

Wheel

Hubs

Wheel

Nuts

Whoel,

Removing

a

Windscreen

Washing

Equipment

and

Fitting

25,
25'

25,

5o

ro9

23

29,

75

t8,

7z
74

ro8

32,

64
4r

42
32
42

7s

73
7r
7r
7r

r05

INoBx

or IrrusrRATroNS.

r3

INDEX

OF ILLUSTRATIONS

Frc.

Pecp

No.

No.

Adjusting the Inlet

Valve Rocker

Clearances...

Air Cleaner-Standard

Type

Air Cleaner-Oil

Bath

Type

Axle

Casing, Rear

I3ox,

Fuse,

Output Regulator

and

Cut-out

Brakes,

Adjustment

of

Front

Brakes,

Adjustment

of

Rear

Braking

System, Diagram

of

Carburetters, in Position

on

Carburetter,

Exploded

View

Engine

Chassis Lubrication

System, Diagram

of

Chassis

Oil

Pump ...

Contact Breaker and

Distributor

Contact Breaker, Interior

View

Controls,

Driver's

Controls,

Radio
Crankcase Drain Plug
Damper, Rear Hydraulic

Shock

Diagram of Braking

System

Diagram, Electrical

Wiring
Door Hinges
Drain

Tap Cylinder

Jacket

Dynamo

Engine Lubrication

System

Engine Oil Filler

Cap and

Dipstick

Engine Oil, Relief

Valves.

Entered

Stud

at

Top

Fan

Belt

Adjustment
Filter, Rear
Fitting

Jack

to

Slide

Front

Brake

Adjustment

Front

Compartment Picnic

Table

Front

Hub and

Wheel,

Section

of

Fuel Pumps...

3

r5
r6

2+

42

r8
r9

t7
I3
I4

J

4
43
4+

I

5o

IO

27
r7

4o

53
38

4r

6

9

33
37

t2

z8

r8

s4

35

II

42

32

53
54
66

88
6o
6o

56
48
5o
36
35

93

94

20

r03

43

7o
56

85

ro8

8z
86

39
39
42
74

8o
47

73
6o

ro8

76
45

88

Fuse

Box, Output

Regulator

and

Cut-out

r4

TnB

'R'

Tvpn BBrstrnv.

Gearbox

Access

Points

Gearbox,

Underneath

View

Gear

Range Selector

Lever

Guide

to

Crewe Service Station

Guide

to Main Service Station

Headlamp, Changing

the

Heater Isolating Tap

Hydraulic Shock

Damper,

Front

Hydraulic Shock

Damper,

Rear

Elydraulic

Master Cylinder and

Bulb

58

rr5

57

IT4

47

IoI

3e

83

z6

68

27

20

+5

5

6

Frc.
No.

2T
22

2

Prcr

No

63
64

22

94

36
39

IIO

95

73

40

42

73

73
65

35

r03

6o

77
32
74

68

7o
6r

Lubrication System,

Lubrication

System,

Luggage and Spare

Ignition Coil

Chassis
Engine

Wheel Compartment

Motor,

Starter

Mounting

Rear Wheel

Oil

Filter

Oil

Relief Valves, Engine

Operating

Wheel

Jack

Positioning Rear

Wheel

Propeller

Shaft

Pump, Chassis Oil...

Radiomobile Controls ...
Rear

Brake

Adjustment ...

Rear Hub and Wheel,

Section of

Rockers, Adjusting Valve...

Rotating Front Wheel
Shock

Damper, Front Hydraulic

Shock

Damper, Rear Hydraulic

Reservoir

56
46
3o

8

9

29

3r.

23

4

5o

i9
36

3

32

z6

Side

Lamp

Side

Lamp

Starter

Motor

Steering

Column

Upholstery,

fnterior

Wheel

Balance

Weights

Windscrepn

Washing Equip,ment

Windscreen

Washer,

Reservoir

and Pump

Wiring

Diagram, Electrical

27

70

48

ro2

49

ro2

46

95

25

67

55

ro9

34

76

5r

ro5

52

ro6

40

85

THE

SECRET

OF

SUCCESSFUL

RUNNING

Before a

Bentley car

is

sold, it

is

very carefully

tested

and adjusted

by

experts.

It will

run

best if

no attempt

is

made to

interfere

unnecessarily

with

adjustments.

An

owner

would

do

well to

instruct

his driver as

follows:-

Lubricate

effectively,

in strict

accordance

with

the

advice

given

in this

book,

and do

not

neglect

ony

part.

Inspect

all

parts

regularly,

but

take

care

not

to

alter

any adjustments

unless

really

necessary.

r5

SERVICE

FACILITIBS

FOR

BENTLEY

CARS

our

interest

in your

Bentley

car

does

not

cease

when

you

take

delivery

of

the

car.

It

is

our

ambition

that

every

purchaser

of

a Bentley

car

shall

continue

to be

more

than

satisfied.

With

this

end

in

view,

the

"Special

Retailer,,,

through

whom

the

car

was

purchased,

has

estabrished

a

properly

equipped

Service

Station,

staffed

by

men

who

have

been

specially

trained

in

servicing

Bentley

cars.

In

addition,

on

the

staff

of Bentley

Motors

(r93r)

Ltd.,

there

are

experts

whose

sole

duty

it is

to

maintain

contact

with

the

"special

Retailers",

and

they

are

available,

at

all

times,

to

be

called

in for

consultation

on

any

matters

affe6ting

your

car.

If,

therefore,

you

require

any

assistance,

we

ask

that

you

should

immediately

contact

the

"special

Retailer",

who

will

be

only

too

pleased

to place

his facilities

at

your

disposal.

If

necessary

he

will call

in for

consultation

our

expert

in

that

area.

It

is

earnestly

hoped

that

this

arrangement

will

prove

of

mutual

benefit,

as

we shall

thus

be

kept

in

constant

touch

with

our

customers,

who

may

be

spared

the

trouble

of a long

journey

to one

of

our

Company's

Service

Stations.

In

the

event

of

it

being

more

convenient

to call

on

us

direct

for

assistance,

our

main

Service

station

at

Hythe

Road,

Willesden,

London

N.W.ro,

and

the

one

at

our

factory

at

crewe,

will be

ready.at

all

times

to help.

(See

maps

at

end

of

Handbook.)

r6

LEADING PARTICULARS OF

CHASSIS

Engi ne,

Six

cylinGers,

3&"

(gzm/m.)

bore,

4t"

Fr4m/m.)

stroke,

4,566

c.c.,

cubic capacity.

Mono-bloc

casting, detachable cylinder head, overhead

inlet

valves,

side exhaust valves.

Aluminium alloy

pistons.

Engine Lubrication.

Pressure feed to all

crankshaft

and

connecting

rod

bearings.

Relief valve,

providing

positive

low-pressure supply to the valve

rocker shaft,

from

which

the

inlet

valves,

push

rods and tappets

are

lubricated.

Two-gallon

capacity

sump.

Ganburetten.

Two

special type

S.U.

Air intake silencer and air

cleaner.

Fuel

System.

Eighteen-gallon

tank at rear of chassis.

Supply

by

electric

pumps.

Fuel level

gauge

and

warning light on

instrument

board.

The

warning

light

indicates

when fuel is

low.

Cooling

Systotn.

By centrifugal

pump

circulation and fan.

Thermostatically

contrblled.

Coolant

temperature

thermometer

on

instrument

board.

Electrical Equipment,

Twelve-volt

system

with automatic

regulation

of

dynamo output.

Starter

motor

with reduction gear

and

pinion providing

gentle

engage-

ment. Battery of

55

ampere-hour capacity.

Geanbox,

Four forward

speeds and

reverse. Fully automatic

with over-

riding

hand and

"kick-down"

change

speed control.

Glear

Ratios.

Rear Axle rst

znd

3rd

4th

Speed.

Reverse.

Ratio.

Speed.

Speed. Speed.

(Direct.)

3,I3:r

14.23:r

g.8z:t

5.4:r 3.I3;r

t6.o4:r

Rear Axle.

Semi-floating type.

Hypoid

gears

with differential.

Torque and

brake reactions

taken

by

road

springs.

Rear

Suspeneion.

Semi-elliptic

springs in combination

with controllable

hydraulic

shock

dampers.

Fnont

Suspension.

Independent;

open

helical

springs

in

combination

with hydraulic

shock

dampers.

Steering.

Cam-and-roller

type.

Bnakes.

Hydraulic

operation

on front

wheels, mechanical

operation

on

rear

wheels assisted

by

mechanically driven

servo

motor.

Hand

brake

operates

on rear

wheels.

Chassie

Lubrioation.

Centralised

chassis

lubrication

system supplied by foot-operated

pump

and

reservoir

on

dashboard.

Road Wheele,

Detachable

steel

wheels, fitted

with 6.5o"

by

16' India

Super

Silent Rayon

tyres.

r8

Dimensions.

Total

length

overall,

Width

of

car ...
Wheelbase
Track-Front

...

Rear

Turning

circle...

Weight

(kerbside)

Overall

height

including bumpers ...

38$

cwts.

r6',

7t"

5'

r.o"'

ro' oo

4'

8+"

4'

Tot"

4T'

20

(approx.

).

5'

5f"

Ghassis

and Engine Numbers.

The chassis

number will be

found

on the

identification

plate

fixed

.to

the front of the dashboard

under the

bonnet, and

also

stamped on

the left-hand

side frame

member

just

in front of

the dashboard, under

the bonnet.

The

engine number is stamped

either on the

front left-hand

crankcase

lifting lug, or on

a boss on

the crankcase above

the front

left-hand

lifting lug.

r9

20

TsB

'R'

Typn

BsNruBy.

f3l4l

?o lB

19

2l

Fig.

1.-GENERAL

VIEW

OF

DRIVER'S

CONTROLS.

1.

Steering

wheel.

2. Gear

range

selector.

3.

Ride

control.

4.

Hand

brake.

5.

Side

scuttle

ventilator.

(Pull-open,

push-shut).

6, Accelerator

pedal.

7. Brake

pedal.

8. Dip-switch.

9.

Cigar

lighter.

(Push-in,

lighter

springs

up

when ready

for use.)

10.

Instrument

lights.

(Pull-on,

push-off.)

11. Screen

wiper

switch.

(Turn

clockwise,

first

position-normal,

second

position-fast.)

12.

Fuel

warning light.

(Steady

glow

at 2-3

gallons

reserve.)

13.

Oil level

indicator. (Press

button

and read

on fuel

gauge

dial.)

14.

Direction

indicator

warning

light

(when

fitted).

15.

Map lamp

switch.

(Push-on,

push-off.)

15. lgnition

warning

light.

17.

Trafficator. (Self-cancelling.)

18. De-mister

booster

fan.

(Turn

clockwise,

first

position-fast,

second

position-slow.)

19,

Fog

lamp.

(Pull-on,

push-off.)

20. Rear window

de-mister.

(Pull-on,

push-off.)

21

Heater.

Turn

clockwise,

first

position-fult

on,

second

position-medium.)

Srenrrwc

rnn

ENcTNE

AND Dnrvrxc rnn

Cen.

2l

CHAPTER

I

Starting

the

Bngine

and

Driving

the

Car

_,

Starting

the

Engine-Use

of

Starting Handl,e-Automatic

Gear

C h

an

ging

7-T

ou

S t

ar ting

-F

u

el,

F

e

ed-F

u eI G aug e-C

has

si s Lub

r i cati

o n

-c

ontr

ol,l,abl

e S

ho ck D

arnp er s-B

att ery C

har

ging-Li

ghting

C ontr

ol,

and

Suitck-Accessories-Engine

Thermostat

anA- Theirnomiter-Coolant

Leael,

in

Radiator-Frost-Fitting

of

Snoa Chains.

Starting

the Engine,

Switch

on the ignition

by turning

master

and ignition

switches

on

the instrument

board to On.

The

master

switch

controls all the

electrical

system, excepting

the

electric

clock, inspection

and

roof

lamps,

the latter

being left

always

available

for convenience

when

entering the

car in

the

dark.

A small red

warning light

on the instrument

board

will

be illumi-

nated

when the ignition

is

switched

on, but

will be

extinguished

when

the engine

speed is

sufficient

to

cause the

cut-out

contacts

to

close.

Ensure

that the

gear

lever

on

the steering column

is

in neutral,

quadrant gear

position

"N",

as

it is only

in this

position

that

the

starter

switch is

operable.

Before

starting

the

car

in

temperatures

aboae

freezing point,

f,rst

defress

the accel'erator

pedal,

slightl,y and

tken al,loa

it to

return

t6 its

norrnal

position.

This permits

the

throttle stop on

the carburetter

to

re-position

itself correctly

according

to

engine temperature.

-

Under v_ery cold

conditions,

in temperatures

of below

freezing

p-oint,

it

will be necessaly_

to

depress the accelerator pedal

slightlR

about a quarter

of its full

travel, and hold

it

depressed

while the

starter button

is

being

operated. Immediately

the

engine fires,

the

accelerator

pedal

should

be released.

Depress

the starter

button

firmly,

an appreciable

pause

must

be

made

between

the operatign;

of switching

on the

ignition

and,

depressing

tke starter button,

especially

uhen

making a

start

from

cold.

­This

ii

necessary

in

order

to

give

the

pumps

time to fill

the float

chambers

of

the carburetters.

Use of

Starting

Handle.

,

It,is

imperatiae

uhen starting the

cngine

with the

starting

hand,l,e,

that tke

gear

leaer

must be at Neutral,.

22

TttE

'R'

TypB

Bpr.lrrpv.

Automatic

Gean Changing'

The

gearbox is

fully

automatic

in operation_

throughout

the

r?nge

of

the

g"ear ratios;

however,

a

manuaf

control

let'er

is

mounted

on

the

stee"ring

column, by

means of which

a selectio1

Tay

be

made

of

the desired."ranges

best"suited

to the

operating

conditions,

thus

glvilg

the

driver

great"er flexibility

of

the

conirol

and

enabling

him to

use

his

judgment

and

skill.

Three

forward

speed

ranges

are

provided,

also

neutral

and

reverse.

The

quadrant

is

marked

as follows:-

.

The

gear ratios available

in

each

of the

positions

are

as

under:-

"4"--Top,

3rd,

znd

and

rst.

rrr"-Jrd,

2nd

and rst.

"2"-2Y1d

and fSt.

For

all normal driving

conditions

the

lever

is

placed

in the

position

marked

"

4"

,

when

all fdur

speed.s

are

available

under

the

control

of

the

auto**ti.

"control

unit"]

which

will

select

the

suitable

gear ratio

according

to the

degree

of

throttle

opening

and

the

speed

of

the

car.

The

gear

lever

quad-

rant is

provided

with

a

gate

between

positions

"

2"

and"3"

and

a button

on

the

lever has to

be

depressed to

move in

or

out of

neutral or

into

reverse,

thus

preventing

inadvertent engagement

with

an unwanted

gear.

For

greater control

of

the

car

when

touring

in hilly or difficult

coun-

try,

the

gear lever

should

be

placed in the

position

marked

"3".

The

change either

up

or

down,

between

4th

and

3rd

speed,

can

be

made

at any

*noment

by

the

simple

moverRent

of

the

lever.

Easing

the

press-

ure

on the

accelerator

R.

2.

3.

4.

N.

Fig.

2.-GEAR

RANGE

SELECTOR

LEVER.

1.

Lever.

2. Neutral and

reverse

lock

button.

3. Underseat

heater.

4. De-mister.

(Pull

out-hot,

push

in-cold.)

pedal

facilitates

the

change, but this

is

not essential.

Should

the

driver

desire

maximum acceleration,

he

may

obtain

a

lower

ge?r at full

throttle

by depressing

the

accelgr_atgr

pedal

beyond

the no-rmal limit

of its travel,

so

actuating

the

kick-down

switch.

(T'o

be inserted in

Bentley

Handbook

No. XIV,

to

face

page

4.)

COASTING.

owners are advised

that

coasting

or

"freewheeling"

down hills

uith

the

engine

switched

off must

definitely

be avoided,

as

this

is likely

to

cause

severe

damage to

the

Automatic

Gearbox

mechanism.

This damage

can

occur

with

the manual

control

lever

in

anv

of

the five

positions,

including

position

"N".

Similarly, if,

in

the

unfortunate

event

of an accident,

it

should

be necessary

to give

instructions

for

the car

to be

towed,

owners

are

requested

to instruct

that the

following

procedure

should

be carried

out

before

the car is

moved,

to

safeguard

the gearbox

frcm

further

damage.

.(i)

The car

should

not

be

towed if

there is

any

sign

of mechanical

failure

or breakage

in

the

gearbox.

In

this case

the

car

must

be

transported.

(ii)

when

satisfied

that

the gearbox

is

undamaged,

remove

the

front

interior

carpet

to

obtain

access

to the inspection

cover

in

the

floor (see

5,

Fig. 21),

page

63.

Remove

the

six

screws

and

the cover.

(iii)

Release

the locknut

and

slacken

off the rear

band

adjusting

screw

(5,

Fig. 21)

+t

complete

turns.

Re-tighten

the rbcknui

and

replace

the inspection

cover,

screws,

and

front

carpet.

(irr)

Keep

the control

lever

at

r(N"

throughout,

and

maintain

when p_ossible

a

towing speed

between

15

and

z5

miles

per

hour.

Distances

must

at

all

times

be kept

to a minimum.

IMPORTANT.

At no

time must

a

speed

of

z5

miles

per

hour

be exceeded

whilst

towing.

BBNrrny

Morons

(tgSr)

Lrn.,

LoNnoN.

Leaflet

S.B./rb/Se.

SranrrNc

rnn ENcrNr aNp

DnrvING

rnp

Can. 23

It should

be noted that

although the

hand

control lever

may be

set

in

position

"3",

this

gear

ratio

will

not be

held

if

the

engine

revolutibns

are excessive. The

automatic

control

unit

will over-ride

this

setting

and the

gearbox

will automatically

change

up

to

4th

gear.

When

descending

very steep

gradients, the

gear

lever

should

be

placed

in the

and

position.

Onty

at prolonged

halts,

due

to traffrc

jams,

etc.,

is it

necessary

to engage

neutral; at all

ordinary traffic

controls,

the

gearbox may

be left

in

the

gear

range

then

in

use.

Reverse

can be engaged

while the

car

is

travelling

forward

at

any

speed

below

ro

miles

an

hour.

This

feature

can

be

used

to advantage

'should

the

car become

embedded in

deep

snow, when

by suitable

timing

of

the

engagement

of reverse

and second, the

car can be rocked

out of

the

rut.

When the engine

is

stationary,

a

parking lock

is

provided by

placing

the

hand control

lever in

"R".

The steering

column

control lever

moves through

a

"g*.e"

between

positions

"3"

and

"2";this

design

of

quadrant

allows changes

between

4th

and

3rd

speed

ranges to be

made

without

risk of

entering

the

znd

speed

range. Likewise,

changes between znd

speed

range ahd

reverse

when

"shunting"

are facilitated.

It

should

be noted that

when starting

the

car from

cold

the engine

will run at

a

"fast

idle", with

the consequent

build-up

of an operating

oil

pressure

in

the

gearbox. If when

parked in a confined space

it

is necessary

to engage

reverse

gear

from

neutral, thereby temporarily

engaging

the

forward speed

ranges,

care

must

be

taken

not

to

release

the

brakes

until the

gear

lever is

in

position

"R".

Tow

Starting.

If it

should

be

necessary to start the

car by towing, the

gear

lever

should be placed at

position.

"2".

When the

car speed

reaches about

zo

miles per hour,

the

engine

will start to

turn

over

and fire. The

lever

should

then

be

placed

in

the

neutral

position, and care

should

be

taken

not

to

have the throttle

too

wide

open or

the

car

may

accelerate

too rapidly and

overtake the towing

vehicle.

Fuel

Feed.

Fuel is

supplied

from

the

main

tank to the carburetter by

means

of a

dual

electric

pump

mounted

in

the

frame (see Fig.

11). The

total

cilpacity of the main tank

is

r8

gallons.

Fuel

Gaugo.

The electric

fuel

gauge

on the

instrument board

is graduated

to

register

the total

quantity

of

fuel in the'main, tank. The

gauge

is

inoperative

when the ignition

is

switched off.

Special contacts carried by the tank

unit cause the

green

warning

lamp

to light when only about three

gallons

of

fuel remain in the

tank.

24

TnB

'R'

Tvpe Benrr,rv.

Ghassis

Lubrication.

When

starting

the car

for

the

first time

in

the

day, it

ig

1

g99d

plan

to

form

the-habit

of operating

the

chassis

oil

puryp

pedal.

The

loot-operated

pump

should

6e

used

according

to

the

mileage

travelled,

and

the

pedafshouta be

given three or four

strokes

at

first starting,

and subsequently

repeated

every

zoo

miles.

This

will

ensure

adequate

lubrication at remote

parts

of the

system.

Controllable $hock

Dampers.

In order to

provide

comfortable

riding at

all

speeds, controllable

shock

dampers are

fitted

to the

rear

axle.

The

control

is

effected

by

the

lever,

mounted

above

the steering

wheel, and marked

Ride

Gontnol.

For

ordinary town

work, or touring

with

moderate

loads,

it will

be found that

the damper

loadings

as set

by the

pump are

adequate

when the hand lever

is at

Normal.

With

heavy loads,

improved

riding

comfort

will

be obtained

by

moving

the lever towards

Hard,

the

control

being

progressive.

Battery

Ghanging.

This

is

entirely

automatic,

as the

provision

of

an

automatic

output

regulator

in

conjunction

with

a shunt

wound

dynamo,

adjusts

the

charge

rate

to suit

the state

of the

battery.

When

the

battery

is low

in

charge,

the

arnmeter

on the

instrument

board will

show a higher

reading

towards

Gharge

than

it

will

when

the

battery

is

well charged.

In

making

such

a

compari-son,

howet'er,

other

factors which

affect

the ammeter

reading must

be taken

into

account, chiefly engine

speed

and

current-consuming

apparatus

in

use at the time.

Whenever

the

master switch

and the

ignition switch

are

On, and

the engine

running

above

idling speed,

the

battery

is being charged.

This

should be checked

by reference

to

the

ammeter.

Further

information

regarding the electrical

system

is

given

in

Chapter

X.

Llghting

Gontrol

and Switch.

As

already

mentioned,

the movement

of

the master

switch

and

the

ignition switih

to

On

not

only switches

on the

ignition

and charge,

but

brings

into

operation

the electric

fuel

pumps

and fuel

gauge.

The

ignition switch

also

switches

on

a

red warning

!igh!

on the

instrumeit

board,

which

is

automatically

extinguished

when

the

engine

is

running

at

a speed

sufficient

to

cause

the

dynamo

to excite

up

to battery

voltage.

To be

inserted in

Bentley

Handbooks

to

face

page

zJ.)

SNOW TYRES.

Special tyres

are

now

available

from

certain tyre

manufacturers,

which

are recommended

as an

alternative to

"chains",

as they give

'

an easier

and better

ride

and

allow

faster driving

over

snow-covered

roads.

The

tyres

recommended

for

use

on

the Bentley

car are-

"India-Winter

Type".

It is

suggested

that

two

spare

wheels

might

be fitted

with

Snow

Tyres

and held

in the garage,

for

change-over

with the rear

wheels

of the

car when

conditions

warrant

their use.

There is

no

objection

to the

use

of

these

tyres

on ordinary road

surfaces,

except that they

would

probably

be

noisy.

The

tyre pressures

should

be maintained

at

the normal

tyre

pressures

as

quoted

in the

Handbook.

BBNrrBy

Morons (tgSt)

Lrurrno,

Loxnou.

Lea0et

S.B./15/53.

SrenrrNc

rrru ENcTNE

AND DnrvrNc

rnp

Cen.

The

master

switch controls

the

head,

side

and tail

lamps, alternative

On positions

being

provided,

viz.:-

S and

T.-Side

and

Tail

lamps

on.

H,

S and

T.-Head,

Side

and

Tail

lamps on.

FL.-"Parking"

lights on,

e.g. Side

and Tail lamps on,

accessories

off.

In addition, a foot

operated

switch

is

provided,

by

means

of which

the beam

of the

driving

lights

is altered

to allow

anti-dazzle

precautions

to operate, thus extending

courtesy

and

safety to

passing

traffic.

Accessories.

'

Windscreen

wipers, washers and

de-misters

are

fitted,

also

direction

indicators and a car heater,

these being

operated as

under:-

The

windscieen wiper has

two speeds

controlled by a two-position

switch

(see Fig. 1).

Operate

by turning

switch

knob to

the

right:

the

first

position

gives

SLOW,

further

turning

to

the right to the

second

position

gives FAST.

Hard over to the left is OFF.

The

higher speed of

wiping

is intended

for

use during

heavy

rain.

It

should

not be used in heavy

snow or

with a dry or

drying wind-

screen,

i.e. when

the load

on

the

motor is in

excess of normal.

The

windscreen wiper motor is

fitted

with

an automatic

switch
which breaks the electrical circuit if the motor overheats; and this
may

occur if the high

speed

position

is

used when the windscreen

is

nearly

dry, causing a

high resistance to the blade movement.

When

the circuit breaks, the

wiridscreen wiper will stop

but

will restart

if

allowed

to cool

for

about

ro minutes, meanwhile the

switch should be

turned

to the slow speed

or

"off"

position

to

prevent

further over-

loading

unless the rain

is

heavy.

For

washing the windscreen, two small

jets

are arranged on

the

scuttle to squirt

fluid

on

to

the windscreens

within the traversing

arc

of the

wipers.

A press

button on the

facia

should

be

depressed when

required; on releasing,

two

jets

of fluid

will

be

directed

on to the

wind-

screen.

The

screen wipers should then be switched

on

to complete

the cleansing.

For

de-misting the windscreen, warm

air from

a special

heater

under the front

wing

is

taken

through

suitable ducting

to

vents

in the

capping

rail.

The forward motion of the car is normally sufficient to

ensure

adequate,

de-misting. Under severe

conditions, switch on the booster

motor

(18,

Fig.

1

)

.

The

raised arm trafficator type of indicator is

fitted,

and the

control

switch

is mounted on the

centre

of the capping

rail

as

shown

in Fig. r.

A

car heater is

fitted

in the

front

compartment

under

the seat.

A

push-pull

switch

on the facia

(3,

Fig.

2)

operates a

valve to

control the

water

supply

to the heater. A rheostat

switch

on the

facia board (21, Fig. 1

)

controls

the

fan

for

air circulation.

26

TnB

'R'

TYpB

BBNToY

A

press

button

switch

is also

available

for

ascertaining

the engine

oil

level

which

reads on

the

fuel

gauge.

(See Fig.

1.)

These

are all controlled

by the

master

switch,

and

it is

recommended

that

the

master

switch

be

regularly

used

to avoid

leaving

the

car

with

one

of

the

accessories

in operation.

Engine

Thermostat

and

Thermometen.

A

thermostat

is

provided

in

the

upper

radiator

coolant

Pipe

which

automatically

restri6ts

the

flow through

the

radiator,

until

the

coolant

in the

system

attains

a temperature

of

about

78"

C.

A

thermometer

is provided

on

the

instrument

board to

indicate

.

that

the thermostat

is operating

properly

and that

there

is

no

shortage

of

coolant.

Goolant

Level

in

Radiator.

The

radiator

filler cap,

which

is located

beneath

the

bonnet

on the

left-hand

side,

should

de

removed

occasionally

for

inspection

of

the

coolant

level,

but

it nrust

not

be remoued

when the

engine

is

running.

The

level of

the

coolant

should

be

maintained

to the

bottom edge

of

the

filling

orifice.

Top

up

if necessary

with

the

correct

anti-freeze

mixture.

(See

page 82.)

Frost.

The

car

is delivered

with

a

suitable

anti-freeze

mixture

in the

cooling

system.

(See

page

79.)

If

the

original

coolant

has

been

replaced

with

water,

and the car

has to

stand

dxposed

to

frost with

the

engine

not_

running,

it is of

vital

importance

thal

the

system

should

be

drain"9.

by opening

the

drain

tafs

on the

water

pump

inlet

pipe, and on

the

cylinder.block

(1,

Tig.99),

arid,

releasing

the

file?

cap.

-The
car

heater

m.ust

also

be

drained

by

opening

the tap on

the

return

PiPe.

Before

attempting

to

start,

or

eaen

rnoae

th,e

engine

again,

hot

water

should

first be

foured

over the

water

Pump,

as otherwise

damage.ryly

be

caused

to

the

pump

rotor

by the

plesence

of

particles

of

ice

within

the

casing.

Warm

wdter

can

be used

with

advantage

for

refilling

the

radiator.

Fitting

of Snow

Chains.

In the

event

of snow

chains

being

necessary,

they

should

be

fitted

to the

rear wheels

only.

A farsons

chain,

known

as the

"special Bentley

Type",

is avail-

able. It

is

recommended

that

these

be

obtained

through

Messrs.

Bentley

Motors

(rggr)

Ltd.,

or

one

of

their

"Special

Retailers",

in

order

to ensure

the

supply

of

the

correct

type.

When

fitting

these

special

chains,

it

is essential

to

commence_by

fastening the

oie

hook

5n

the

inside

of

the wheel

and

to

ensure

that

the

outir

joining

links

are

fitted

as low

down

on.

the

tyre

wall as

possible.

ihe

t6ttsioning

springs

which

are

supPlied

to

go

on the

outside

of the

wheel

must

always

be

fitted.

(To

be

inserted in

Bentl'ey

Handbook, No.XIV, to

face

page

27.)

AUTOMATIC GEARBOX.

SERVICE

AFTER

1,(x)O MILES RUNNING.

.

I m

poptant.
During the

early

life of the Automatic

Gearbox, a certain

amount

of initial

bedding-in of the

brake bands occurs. This

cannot

be

compensated for in

the

original factory adjustments, and

it

is

therefore

most

important

that

after the car has completed the first

r,ooo miles

running, it should be

taken to

the Bentley Retailer

in your territory

for the appropriate adjustments

to be carried out.

No charge

will

be made for

this service.

If it

is inconvenient

for you

to send the

car

to the

retailer from

whom

it

was

purchased,

any Bentley

Retailer will be

pleased

to

carry

out

this

adjustment.

Bnxrrrv Morons

(rgSr)

Lro.,

Lottpot*.

Leaflet

S.B.iSblSe.

Ppmoorc

LunnrcerroN

AND

ArrsNrtoN.

27

CHAPTER

II

Periodic

Lubrication

and

Attention

LUBRICANTS

RECOMMENDED

.Eng

i

ne,

For

normal

operation

of the car under

Temperate

climatic

con-

ditions,

Bentley

Motors

(tgfr) Ltd.

recommend

a

first quality

oil oJ

viscosity

S.A.E. zo

tor

the

engine

for

all-the-year-round

use, but,

if,

conditions

permit of long

journeys

of

maintained

high speeds,

a heavier

duty

oil of

S.A.E.

3o

grade

would

provide better

oil

mileages._

Also, it

would

be

advantageous

to use

an S.A.E.

3o

grade oil

when

the

car

is

normally

operated under Tropical

climatic

conditions.

On

the

other hand,

under extreme

Winter

conditions

of sub-zero

temperatures,

the use

of a lighter

grade oil

of

S.A.E.

ro viscosity

would

provide

easier

starting

and satisfactory

lubrication.

The

following oils

are recommended:-

Shell

X.roo-eo

X.roo-3o

Vacuum

Mobiloil Arctic Mobiloil

A.

Equivalent

oils to

the above

are also

marketed by:-Sternol

Ltd.,

Alexander

Duckham &

Co. Ltd.,

Esso Petroleum

Co.

Ltd.,

Gulf Oil

(Great Britain)

Ltd.,

and Dalton & Co.

Ltd.

In

the

instructions

which

follow,

reference

is made

to

oil

"A"

or

"8"

as

above,

i.e. viscosity

zo

or

30.

Gearbox.

The

automatic

gearbox should be

filled and topped

up

only

with

Automatic Transmission

Fluid,

Typ"

"

A",

having an Armour

qualifi-

cation

ttumber

prefixed by AQ/ATF.

Either

of the following

may be used:-

..Att

S.A.E.

zo

B.P.

Energol zo

Wakefield's

Castrolite

..Btt

S.A.tr.

3o

Energol

3o

X.L.

Typ"

AQlATF-ror

Type

AQlATF-ro3

Typ"

A9lATF-z6t

Type A8lATF-r56

Vacuum

Shell

B.P.

Wakefield's

...

General

Motors

Mobiloil Fluid zoo

Donax T.6
Energol Automatic

Transmission

Fluid.
Castrol TQ.
Hydra-Matic Fluid

r

28

Tnn

'R'

Tvps

BBNrrnv.

Rear

Axle.

Wakefield's

Special

Castrol

Hi-press S.C.

(If

this

is unobtainable,

use

a first

quality Hypoid oil of viscosity

S.A.E.

9o.

Do

not

mix these

oils; drain and

refill.)

Garbunetter

Air

Valve Damper,

Viscosity ro

oil;

any

of the following

may

be

used:-

B.P.

Wakefield's

Shell

Vacuum ...

Steering

Box-Ghassis

Oil

Contact Breaken Cam

Pad.

Viscosity

3o

oil, as under

"B"

above.

Hydraulic Shock

Dampens.

Viscosity

zo

oil,

as

under

"A"

above.

Propeller Shaft--Door

Hinges.

Vacuum

Mobilgrease

No.

a.

Distributor

Grease Gup.

High Melting Point

Grease.

Hydraulic

Brake Fluid.

Genuine

Lockheed Hydraulic

Brake

Fluid,

CAPACITIES

U.C.L.
oilit.

Donax

A.r.

Mobiloil

Arctic Special

Pump-Stanter

Motor

Geans-

Engine
Gearbox
Rear Axle
Chassis

Oil Pump

Cooling

System

Fuel

Tank

S.A.E.,

Spec.

70,

R.2.

pints Imp.

approx.

pints I*p.

,,

pints Imp.

,,

pints Imp.

,,

pints I-p.

,,

gallons

I*p.

,,

x6

20

rfr

2

32

r8

GENERAL

In addition to the

points

supplied

with

oil

by the

centralised

system, there

are

others-which, fof

various

reasons,

cannot

be

fed

in

this way

and

must,

therefore,

be

lubricated

by

hand.

In the

notes which follow,

these

poiirts

are classified

as

far

as

possible

under

mileages, or

according

to

the

usage

of the

car.

It

is important

that

careful

attention

should

be

given to

their

lubrication

3o

as to

reduce

wear

and

eliminate

mysterious

squeaks

and

rattles.

Further

notes

are

included covering

the

periodic operations

and

adjustments

which

are

necessary.

Points

for

Refular

Attention

aacording

to

Use

of Car

FREQUENTLV,

OR

DAILY

IF

LONG JOURNEYS

ARE

CARRIED

OUT

1.-Engine

Oil.

_Inspect

oil level

on

dipstick

or

electric

gauge

when

engine

is

'not.running,

and

top

up as

necessary

with iorrect

oil. Do not

run

engine

with oil

level

down

to

"Min."-mark.

(See page

43.)

(Filler

cap

on

rocker

cover.)

2,-Ghassis

Lubrication.

Use

foot-operated pump

according

to

miteage

travelled.

As it

is

necessary

to

prime

the

system

and

to

expel air,

the

first

stroke

of the

puryp

may not be

effective,

therefore

give

the pedal

three

or

four

strokes

every

zoo

miles. This

will ensure

adequate

lubrication

at

remote parts

of

the

system.

. -Replenish

reservoir

as

necessary,

but

do not

overfill.

Leave

one

inch

between

oil

level and

bottom

of

filler

orifice.

(Reservoir

on front

of

dashboard,

under

bonnet.)

Prnroorc LunnrcerroN

AND

ArrrwrroN.

WEEKLY

3.-Radiator

Goolant.

fnspect

coolant

level

and,

if

necessary,

top

up

with

anti-freeze

mixture

to

maintain

the level-to

the

dottom

fiUing

orifice.

(Filler

cap on header

tank,

under

bonnet.)

4.-Tyros.
Check

the tyre pressures.

These

should

be:-Front,

z4l!r./.q.

in. (r.69

fSl;e.

cm.)

\

Cold.

Rear,

33

lbs./sq.

in. (zgz

kgltq.

cm.i

/

5.-Distributor

Groage

Gup.

,A

Give

grelsg

cup

one

turn;

when

empty,

fiu

with

the

correct grease.

(See

page

a8.)

6.-Windgoreen

Washen.

flspect-

and

refill

reservoir

if

required,

leave

one

inch

between

liquid

level

and

top of

filling

orifice.-

(Reservoir

on front

of

dashboard,

under

bonnet.)

29

the

correct

edge

of the

3o

TnB

'R'

Tvpr

Bpntrnv.

MONTHLY

7.-Battery.
Check

level of acid

in

each cell

and top

up with distilled

water

if

necessary. Check

more

frequently

when

big

mileages

are covered

or

when

the

car

is being run

during

hot weather.

(Access

door in

floor,

under driver's

seat.)

8.-Brakes.
See Chapter

VI

for

description.

The

brakes

should

be checked every

month

or every

2,5oo

miles,

whichever

is the

shorter.

'

To

check the adjustment,

rotate the

adjusters

in a clockwise

direction

until

obvious

resistance

is felt. This

resistance

should

be

equal

for all four

brakes, and

should

the last

"click" on

any

one adjuster

require noticeably

greater

force to

obtain,

this

adjuster

should

be

turned

back

to the

previous "click".

(See

page

59.)

9.-Gearbox.
Run

the

engine for three

minutes

and whilst

still

running

inspgct

the

fluid

level in

the

gearbox

by

means

of

the

dipstick.

(See

Fig.

21.)

If

necessary, repleniih with

one

of

the

recommended

Automatic

Transmissioh

Type

"A"

Fluids, to the

level

marked

on

the

dipstick.

(See

page

27.)

(Access, remove rubber bung. in

floor

in front

of front

passenger's

seat.)

10.-Garburettens.
Inspect oil

level in oil reservoir

of automatic

air valve

guide,

and

top

up

with

the recommended oil.

(See

page

28.)

11,*Oil Bath Air Gleaner.

Every

r,ooo

miles

the

oil

container

and

the

filter

element

should

be removed by

unscrewing the

long

bolt

(1,

Fig.

16)

which

passes

through

the

top of

the silencer.

The oil

container should be

emptied

and

carefully

cleaned,

the

filter

element

being thoroughly

washed

in

petrol

and

allowed

to dry.

Replace the element

and refill the

oil

container

with

oil

"A" to

the

indicated level, and

refix

in

position.

NorB.-The cleaner

should be serviced

at more

frequent

intervals

if

the car is

being

operated

under very dusty

conditions.

(See

page

54.)

Lubrication

and

Maintenance

EVERY

5,000

MILES

l.-Engine

Oil Filter.

Remove

felt element

and washers,

and

discard.

Replace

with

new

element

and

washers.

Refitl bowl with

oil,

re-assemble

and check

that

cover

joint

is oil

tight.

(See

page

4o.)

(Filter

on

right-hand side of engine

crankcase.)

Pnnroorc

LunnrcerroN AND

ArrBNrrorq.

2.-Engine

Oil Sump.

When

engine

is

warm

drain crankcase

and refill

with

oil

"A"

to

the

correct level.

3.-Rear

Axle.

._-

Ingp-ect

oil level

in rear

axle

when

warm,

by

removing

level plug

(Fig.

24),

and. if

necessary,

top

up

with

correct oil to

level

of

hole-.

(See page

66.)

lf !n:

correct oil,

is not obtainable,

do

not

add

a different

oil,

but

il

replenishment

is

necessary,

drain of and

ref,Il with

an

alternatiac

oil

as

directed on

fage

27.

4.-Steering

Box.

Remove plug

and fiIl

casing

with

correct oil

to mouth

of plug

orifice. (See page

62.\

5.-lgnition

Governor.

Remove the

distributor

cover and lift

off

rotor.

Apply

two

or three

drops

of

oil

"A"

to

governor

spindle.

(See

page

g2.l

6.-Contact

Breakers.

Apply

one'drop

of oil

"A"

with

oil-can to

the

pivot

pin

of each

rocker

orrnr (See page gz.)

7.-Distributor

Gam,

._

Apply

one. or

two drops

of oil

"B"

to the cam

lubricator

pad.

(See

page

gz.)

8.-Gontrol

Mechanism.

-

Appty,

q

f9* drops of

oil

"A"

with

oilrcan

to controls

on

steering

wheel (oil

hole),

accelerator

pedal

mechanism,

and all

other

contro-l

points

and

bearings.

9.-Bnake

Gonnectione,

eto.

_Apply

liberally

oil

"A" with

oil-can

to

all

joints

and pins

of brake

rods

and

connections,

or

spray

with

penetrating

oil.

l0.-Boinet

Fasteners

and Lockg.

Carefully

lubricate

with

oil

"A"

bonnet

fasteners

and

locks.

11.-Sparking

Plugs.

Alternative plugs

are

Champion

Type N8,

or

Lodge

Type

CLN,

14

m/m.

non-detachable.

Plugs

should

be

serviced

on

spbiiat

plug

cleaning and

testing

machine, which should

be available

in-

all servic6

stations.

Set

gaps

to

.o3o'

(.162

m/m.).

3r

32

TRB

'R'

TypB

Bsxrrry.

EVERY

10,(xl0 MILES

l.-Starter

Motor.

Open

lubricator

on

side

of

reduction

with oil

"Br'.

(See

Fig. 46.)

Z.-Hydraullc

thock

Dampers.

gear

casing,

and

fill

to

orifice

Inspect

oil

level and

add

more

oil if necessary.

Use onl,y corrcct

oil,, (See page

28.)

3.--Universal

Joints

and

Propeller

Shaft.

Inject

grease

by

means of

grease-gun

into

lubricator

located

at

centre

of

each universal

ioint,

and also into

the

lubricator

on the

sliding

joint.

(See

Fig.

23.)

4.-Valve

Rocker

Glear,arGogr

Check

the

inlet

valve rocker

clearances

and re-set

if

necessary.

This

operation

should

be

performed

when

the

engine

is

cold,

The

method of adjusting

the

valve

rocker

clearances

is

illustrated

in Fig.

3.

Fie. 3.-ADJUSTING

THE

INLET

VALVE RocKER

CLEARANCES.

t.

2.

Rocker

shaft.

Rocker.

3. Ball

ended

contact

screw. 5. Feeler

3auge.

4.

Locknut

Pnnroorc

LusRrcerroN

AND

ArmNnoN.

Before

commencing

to

adjust a

tappet,

it

should be

ascertained

that

the lower

tappet

operating

the

push

rod is

on the

base

circle

of

its

o_perating

cam.

This is best

don-e by

turning the crankshaft

by

hand

until the

valve

has opened

and closed,

and then cranking

round

balf a,,revolution

beyond

this

point.

The ball

ended

contact

screw (3)

is

screwed

into

the rocker

and

locked

with a

nut (4).

On

releasing,.the

nut the

screw can be

turned

by

means of

the

special spanner

provided.

The correct

clearance

for

the

inlet

rockers is

.oo6"

(.tyz

m/m.).

A feeler

gauge

is provided

in

the tool kit, and is

shown in

position

(6),

.

for

measuring

the

clearances.

As

each

contact

screw is

adjusted, its

locknut

should

be securely

tightened

up.

The correct

clearance

for

the exhaust

tappets

is

.ore'

(.3o5

m/m.|,

with

the engine

cold.

These

should

need no

attention between

dd-

carbonising

periods

of

the

engine.

5.-Air

Gleaner

(Standand

Type).

Remove

cleaner

element

lrom front

end

of silencer,

after unscrewing

the

wing-nut

and

taking off

end cover.

Carefully wash

element ii

petrol

or

paraffin

and

afterwards

oil

with

oil

"A".

Drain

off

excess

oil

before refitting.
It should

be

noted

that if

the

car

is

being

run

under

particul"tly

dSsty

conditions,

the element

may nped

cleaning

more

-frequently.

(See

page

53.)

$.-p69pg.

Oil lock bolts

and

hinges

with

oil

"A".

(See page

ro7.)

7.-Hydraulio

Mast6r

Gylinder.

Remove

the filler plug

(1

),

Fig. 20,

and check

the fluid level, top

up.if necessary

with

the

recommended

fluid

(see

page

z8) so

as

to

maintain

the level

at

one inch

below

the

filler

cap.

(Access

through

trap

door to battery.)

EVERY

20,000

MI.LE8

1.-Dynamo,
Inspect

brushes for

wear; to do

this, unscrew

securing screws

and

remove

cover

to

expose brushes.

(See page

86.)

If renewal

is necessary,

remove

dynamo, clean out

dust

and refit

new

brushes,

making

sure that they

are bedding

correctly

on

t[e

commutator.

Refit

dynamo.

c

33

s4

TnB

'R'

TypB

BBNrrny.

2.-Geanbox.
Drain

out

all

the fluid

by removing

the drain plugs

from

the fluid

coupling

_cqslng

and

the

gearbox

sump,

and refilt

witrr the correct

type

of

fluid.

(See

page

27.)

Detailed

instructions

are

given

on

page

63.

3.-Fuel

Filters.

Remove

and

clean gauzes

of rear

filter,

located

on

cross-member

of frame

in front

of

main

tank.

Drain

and clean

filter

sump. (See

PaSe

47.)

Also,

remove

and

clean

gauze

filter

on fuel

inlet

to

carburetter

float

chamber,

taking

care,

first,

to

see that

the

ignition

is

switched

off,

and

fuel pumps

are

therefore

inoperative.

(S.-ee page

47.)

4.-Fuel

Tank.

Release-but

do not

remove-drain

plug

at

bottom

of

main tank

to allow

any

accumulated

water

to

escape. (See page

47.)

5.-Rear

Axle.

Drain

axle

when

warm,

and refill.

Approximately

rf

pints

of

oil

will

be required.

None

but

the

recorn

nended

oil shoul,d

be

used,

and

this should

be

warmed

before

inserting.

6.-Ghassis

Lubnication

System.

Remove

and

discard

felt

strainer pad,

located

at base of

chassis

oil pump.

(See

page

37.)

Replace

riitn

new

pacl.

CBurnatrsED

Cnessrs LurnrcarroN

35

CHAPTER

III

Centralised

Chassis

Lubrication

General

-

Foot-operated

OiI Pumf

-

Drip

Plugs.

General.

A

foot-operated

pump,

with

which. is

combined

an

oil reservoir,

is located

on the

front

of the

dashboard, and

supplies

oil under

pressure

for

chassis lubrication.

Fig.

4.-CHASSIS

OIL

PUMP

AND

RESERVOIR

l'.

F,itTl?',I;

A

diagram

of

the

complete

being

coloured

red.

Red

discs

and the rating

of

each is

given

of the

part

lubricated.

3. Pipe unions.
4,

Strainer.

system

is given

in Fig. 5,

indicate

the

positions

of

in parentheses

against

the

the

piping

drip

plugs,

description

Page 36

DIAGRAM

CHASSIS

LUBRICATION

SYSTEM

CBNtneusED

Cnassrs

Lunnrc.A,tloN.

37

Foot-operated

Oil Pump.

The

chassis

oil

pump

is

shown

in

Fig.

4.

to

the system

is necessary

beyond filling of

correct oil

(see page

z8),

after

removal

of

Normally

no attention

the reservoir

with

the

the filling

plug

(2),

as

directed on

page

29.

It should

not be filled

above one

inch

cover.

fiom

the

top

of the filler

When

the

reservoir is

nearly empty it wil be

found

that

the

pedal

returns instantly

after depression,

due

to

the

presence

of air in

the

system.

On

the other hand,

if

the

pedal

takes

an abnormal

length

of time

to

return

to its raised

position,

this

may

indicate

that the felt

strainer

located at the bottom of

the

reservoir is

choked.

Under these

circum-

stances a new

felt

strainer must be fitted.

This

is

arranged

at

the

bottom

of the

resgrvoir,

and is

removed

by

disconnecting the two unions

(3),

and unscrewing

the

cap

(4).

An

aluminium

distance washer, the

felt

strainer

pad,

and

a

wire

ga:uze

support

can

then be taken out.

When

replacing the

parts,

the wire

gauze

support

should be refitted

in the cap

first, followed

by a new f.elt

pad

and, linally,

the

aluminium

distance washer

with

its

recessed

face

towards

the

felt fad,.

Packing

washers

are

provided

on either side of the aluminium

washer,

and it

should

be observed

that these

are in

position.

Normally,

the

felt

strainer

pad

should

be

discarded

and

a new

one

fitted

every

2o,ooo

miles, as directed on

page

34.

It

should never

be

necessary further

to'dismantle the

pump.

Dnip

Plugs.

The

drip

plugs

are non-adjustable

and non-demountable,

and are

lettered

and numbered to

indicate

their

shapes and

relative

rates

of

oil

emission

respectively, a higher number indicating

a

greater

rate.

The

drip

plugs

never require cleaning, and,

being

non-demountable,

no attempt

must

be

made

to take them

apart.

If one is

suspected

of

being defective,

it

should be

replaced

with a new plug

of the same

rating.

(See

Fig. 5.)

Page 38

DIAGRAM

ENGINE LUBRICATION

SYSTEM

EucrNr

LunnrcerroN

SysrBu.

39

CHAPTER

IV

Engine

Lubrication

System

liu!'ng lZ .sytJ:ry-

o;t_

lymp-oil

Filter-c

rankshaft

and

c onnecting

R.oa:-$elief

values-val,ae

Rochers,

Push, Rods

aia

raplrets-cam"-

shaft-Oil,

Sump-OiI

Leael,

Indicator--Oil,

Pressure.

The

engine

lubrication

system is

of

the

forced

feed,

full-flow

filtered

type,

.and

is

diagram-

matically

illustrated

in

Fig.

6.

Recommended

oils

will

be found

on

page

2I.

Filling

the

System.

The system

is filled,

or topped

up, by

opening

the oil filler

cap

(1,

Fig.

7),

on

the

inlet

rocker

cover,

and

pouring

in

the required amount

of

recommended

oil.

It

should be appre-

ciated that

it

takes a

little time for

the

oil

to

drain through

to

the

sunlp, especially if

the

oil is

cold.

The level of the

oil

should

be frequently

checked with the

dip-

stick

(2,

Fig.

7),

when

the engine

is not

run-

ning,

and

the system

regularly topped

up ag

required

(see

page

z9),

so as to keep

the

level

of

the oil up

to

the

"Max"

mark.

1.

2.

Fig. 7.-FILLER

CAP

Engine

oil filler

cap.

Dipstick.

AND DIPSTICK.

q.

Heater-isolating

tap.

4.

Breather

pipe.

-

Tun

'R'

TypB BeNrrBy.

Oil Pump.

A

gear

type pump

mounted

in

the

lower

half of the crankcase is

driven

by means

of a vertically-mounted

shaft

and

skew

gears from

the centre of the

camshaft.

A coupled

extension

of

this shaft

also

drives the ignition distributor.

The oil

intake

from

the

sump is

of the floating gauze filter type,

ensuring

the

collection of

clean oil, free

from

sludge.-

Oil

is

drawn by

the

pump

through

the floating

intake and

delivered

direct to the

full-flow

fiIter.

oil Filter.

The

full-flow

filter

is fitted

on the right-hand

side

of

the crankcase

as shown in

Fig.

8,

and,

as

previously

stated,

oil is fed

direct

from the

pump

to the filter,

and, after passing

through

the filter, is

returned

via

the relief

valves

to the

main oil gallery,

d.s

shown in the diagram-

matic

illustration,

Fig.

6.

Every

5,ooo

miles,

as

directed on

page

3o,

the filter

element should be

discarded

and replaced with a

new

one.

It is not practicable

to clean

the

felt element, and no

attempt

must

be

made to

do so.

As this

operation entails a

certain amount of

dismantling,

it is

suggested

that

this

periodic

maintenance

should

be

undertaken

by

u

qualified

Service Station.

To

remove the

element,

first,

completelyslacken

off the

dynamo

adjustment.

Then

remove

lock

plate

securing

domed

nut

(1,

Fig.

8), unscrew

the

central

fixing bolt

to

release

the filter

bowl and

pass

the

bowl

forward and

upward

between

the

dynamo

and

valance

plate.

Remove

the

canister

from

the

bowl and dismantle by

un-

screwing

the

knurled

nut

from

the

bottom cover. Extract

the

felt element and

the two

felt

washers, discard and re-

place

with new

ones.

1.

2.

Fig.

8.-OlL FILTER.

Domed

nut

on

centre

bolt.

Filter

bowl.

ENcrNr

Lunnlceuon

SYsmu.

4r

Re-assemble

the

canister and

replace

in

bowl;

ensure that

the

rubber

washer

is

in

good condition.

Ititt

bowl

with

oil

and

replace

in

position.

Replace

wiring

clip

and

re-adjust

dynamo

belt.

On

next

running

the engine,

it

should

be

inspected

for oil

leaks

around the

filter

joint.

Grankshaft

and

Gonnecting

Rods.

The

filtered oil

is

conveyed

to the

relief

valves,

from

where

the

main

oil

supply,

controlled

lt approximately

z$

lbs.

per

square

inch,

.is

delivereaio

ine

main

oil

gallery incorporated

in the

crankcase

casting.

From there

it

is

fed

through

oilways

drilled

in the

crankcase

webs

to

each of the seven

crankshaft

main

bearings,

which

are

of

the

copper-

lead-indium

lined steel

shell

type.

The crankshaft

journals

and

crankpins

are

bored

for lightless

and

to act

as

oil

conduits,

the ends

of

the

holes

being

plugged with

steel

caps.

A11 the

main

bearings

have

circumferential

oil

grooves,

and

radial

holes are drilled

in the crank

journals

to

register with

these

grooves.

OiI

from the

main

bearings

passes to

the

bore

of each

journal

through the

radial transfer

holes

in the

crankshaft

and

then

to the

cranklins

through diagonal

ducts

drilled

in

the

crankshaft

webs,

and

so

thiough

radial

holcs to

each

crankpin

big-end

bearing,

these

bearings

-being
of a similar

type

and

material

to

that

of

the main

bearings.

Each connecting

rod

is

drilled

to

convey

oil

to the

gudgeon

pin

bearing,

the drilling

passing

through

the

big-end

bearing

shell.

Small

holes Jre

cross-drilled

into-this

oilway to

allow a

fine squirt

of

oil

to

lubricate the cylinder walls.

Two

radial holes in

the crankpin

ensure

communication,

twice

per

revolution, with

the oilway

up the

connecting

rod.

Thus,

all the

crank-

shaft

and

connecting

rod bearings

are supplied

with

oil

under

pressure.

Relief

Valves,

The

double

relief valve

unit

is

mounted

on

the

right-hand

side of

the crankcase.

(See Fig. 9.)

The two

valves are in

series,

and their

combined effect

is to

regulate

the

pressure

of the main

high-pressure

supply

to the crank-

shaft

and

connecting rod bearings to

approximately

zJ

lbs.

per

square

inch.

Oil

passing

the

high-pressure valve

(2,

Fig. 9) enters-

the

low-

pressure

chamber

and Jrom

there via

a

pipe

(a)

to

the inlet

rocker

shaft.

In

order

to

ensure a

supply

of oil

to the

low-pressure

system

under

all conditions

of

running,-small

slots

are cut

in

the'seating

of

the high-pressure

valve

(2).

42

TnB

'R'

Typr

BBNrr,nv.

If it is

suspected

that the

relief

valves are

not working

properly,

they can

be inspected

by removing

the

plugs

(3 and 2)

above

the low and

high-pressure

valves respectively.

In each case

the valve

spring

will be found retained

on the

plug,

and when

removed,

the

valves

may be lifted

out for

inspection and

cleaning

of

valves

and

seats.

No attempt

must

be nlade

to alter

the spring

settings by

interfering

with the

springs

themselves,

or by varying

the

number

of washers under

the

plugs.

Care must be taken

to replace

all

parts

in

a

perfectly

clean

state.

Valve

Rookers,

Push

Rods

and Tappets

The

low-pressure

oil

supply

from the

relief

valves is conveyed

Fie.

e.-RELIEF vALVEs.

vla a

pipg

ul$ oilway

through

'!r:

[:l'."t"J,?'J."

"",,.

the

cylinder

block

and head

to

s. L.p.

vatve.

the centre

pedestal

of the inlet

t'.

frti

f,":ffi:'lii

"onn".tion.

valverockershaft,whichisdrilled

,..

Reiurn

from filter.

longitudinally, and

also radially,

in

the

plane

of each rocker,

to lubricate

the rocker arm bearings.

The

rocker arms

are also

drilled, the

holes

running through the

bearing

bushes, to lubricate

the

push-rod

ball ends and

the

ends of the

valve

stems.

Each valve

stem is

provided

with

a

pac"king gland, held

in

position

by the inner

valve

spring, which

prevents excess oil

from

percolating

down the valve

guides.

Oil

is returned

from the.rocker

casing

to the

crankcas-e

through

the

push

rod tunnels.

Gamshaft.

The camshaft, driven

by

single helical

gears,

is

carried in

four

plain

bearings,

these being

lubricated

with

high-pressure

oil through

drillings in

the

crankcase

webs.

The

camshdft

driving

gears

are lubricated by

the

jet

in

the wheel-

case, from the

low-pressure

system.

ENcrnB LunnrcerroN

Svsrnu.

43

Fie. I0.-CRANKCASE DRAIN PLUG.

f.

Drain

plug.

2.

Oil

leyel

indicator float unit.

Oil $ump,

Under

normal cir-

cumstances,

and with

proper

attention, the oil

filter will maintain

the

oil in a clean

con<lition.

Owing

to the

risk of

clilution

of the

oil,

how-

ever,

it

is

advisable to

drain

the surnp

and re-

uew the

oil every

S,ooo

rniles, as directed

on

page

30.

To

drain

the oil, a

plug (1 , Fig.

1O) is

pro-

vided in the

crankcase

surnp,

which should

be

unscrewed

and the oil

allowed

to drain out when the engine is

warm.

On

replacing

the

plug,

ensure that the

joint

washer

is sound

and

in

position.

Oil Level lndicator.

In order

that

a quick

check

may

be obtained, the

petrol gauge

on the

instrument

panel

has been

so

arranged that

by

depressing

the switch

(see

Fig.

1), it

will register

the

approximate

quantity of oil

in

the engine suqp.

The

gauge

is

electrically

connected to

a float unit

fitted

into

the

right-hand

side

of

the

crankcase

sump

(2,

Fig.

10.)

The

reading

should be

taken when the

car

is

standing

as

nearly

level

as

possible.

The amount of oil should be

maintained

at

rtFullt',

this

corres-

ponding

with the

r'Maxtt

mark on

the

dipstick, and showing

that

there

is

approximately

16

pints

of oil

present. A red

line on the

gauge

indicates "minimum",

and

the engine should

never be run with

the

oil level below

this mark.

Oil

Pressure,

Unier normal

conditions of engine temperature and speed,

the

instrument

board

pressure gauge

should

read

approximately zg

lbs.

On

starting

the engine

from

cold, however, a higher oil

pressure

will be indicated,

but

this need

not

cause alarm, as the

pressure

will

fall

when

the

engine

becomes warmed up.

When

the engine

is idling

and

hot, the

pressure

may

fall

to 4 lbs.,

but

provided

that

it increases as the

engine

speed

increases,

this

is in

order.

44

Tnn

'R'

TvpB

Bsurr,BY.

The

car

must

on

no account

be

run

if

the

gauge reads

as low

as

this

continuousl'y.

Such

a

persistently

low

pressure,

which may

be accompanied

by

fluctuations

of the

gauge

needle,

may

be

due to

one

or

rnore

causes.

In the

first

place, it

should

be ascertained

that

there

is

sufficient

oil

in

the

sump-by

referring to

the

oil

level

indicator.

If this

is found

to be

in

order,

the

trouble

may

be due

to a

particle

of

foreign

matter

having

lodged

on one

of

the

relief

valve seatin-gs

and

preienting

the

valve from

closing.

If the

latter

is suspected,

the

relief

valve should

be inspected

and

cleaned

as directed

on

page

42,

(To

be

inserted

in Bentley

Handboak,

No.

XIT/,

to

face'fage

+5.\

FAULTY

IGN

ITION

CONDENSER.

In

cases

where

the engine

misfires or fails

to

start,

and

that

this

'

condition

is

obviously

not

due

to

petrol

starvation,

it

is

possible

that

the

ignition

condenser

is at fault.

Two

condensers

are

mounted

on the

side of the ignition

distributor,

one

being

carried

as

a

spare. (See

Fig.

43,

page

93.)

In

the above

circumstances,

it is

recommended

that the

wire

is

disconnected

from

the

terminal

of the

suspected

cond.enser

and

reconnected

to

the

spare.

The

faulty

condenier

should be

renewed.

at

the

earliest

opportunity.

BnNrrry

Morons (rg3r)

Lrurrnn,

LoNnoN.

Leaflet

S.B,/a/5o.

TnB

FuBr Svsrru.

45

CHAPTER

V

The

Fuel

System

The

Fuel, System-Fuel,

Pumps-Faulty

Operation of Pil,mps-Fuel

Tank-Fuel'

Fil'ters-Fuel,

Gawge-The

Carburetters (Actioi)-Auto-

matic

Air Yal,ae--Throttl'e

Control,-Automatic

Choke

Control-Fl,oat

F

eed'

M

echanisms-Further

Dismantling

of

Carburetter-Adjustment

of

Control's-Setting

of

ldl'ing

Adjustments-Air

Cleaner

aid,

Silencir

(Standard

Type)-Air

Cleaner

and,

Silencer (Oil, Bath

Tyfe).

The

Fuel $ystem.

. -The

fuel

supply from

the

r8-gallon

tank

at

the

rear.of

the

chassis

ir Py

means

of a

double

electric pump

(1

and 2,

Fig. 11),

mounted

inside

the

right-hand

side

chassis

frame

member

below

the

rear

floor.

A

pipe is

arranged

along

the

right-hand

side frame

member

conveying fuel

from

the

tank to

the

pumps.

The

pipe

is

seen

at (a).

A

filter is provided

on

this pipe

line,

being

located

on the frame

cross

member

immediately

in front

of the

tank,

as

shown

in

Fig.

12.

Location of

a

filter

on

the suction

side

that

the latter,

as

well

as the

carburetter,

deleterious effects

of

dirt

or

sediment

in

the

of

are

fuel

the

pumps

ensures

protected

from

the

i.

Fuer

pump.

Fig'

11'-FUEL

PUMPS'.

Inret

oioe.

4.

Fuel

pump.

5. Outtei'pipe.

3.

Valve

caps.

6. Supprerldr

condenlers

From the filter

the

fuel

passes

to

the suction

side

of

the pumps,

and is

delivered

to

the carburetter

float

chamber

by

way

of a pipe

(6),'

and

another

filter

located

at

the float

charnber,

46

TnB

'R'

TypB

BBwrrBv.

Fuel Pumps.

The Juel pumps

(1

and

2,

Fig. 11)

are

of

the

electric,

solenoid-

operated,

djlph_1agT

type,

ald

comprise

two

independent

pumps

complete

ryith

diaphragms,

solenoids,

contact

trip

mtchanism!,

and

suction and

delivery

valves.

Fot\

pumps

deliver into

a common

chamber

and

are

simultaneously

rendered

operative

when

the

ignition

and

master switches

are

tronri.

Duplicate

puqps

?re

provided

primarily

to

ensure reliability.

They

also

ensure

that

there

shall

be no

starvation

of fuel

at

maximum

engine

demands.

If

it

should

ever

be necessary

to

disconnect

the

fuel pipes

at

the

pumps,

it

is important

first

to release

the cover

of

the iear

filter.

(See page

47.)

This

will

prevent

loss

of fuel

by

syphoning,

due to

the

location

of

the

pumps

below

the level

of

the inairi

tank.-

The current

supply

for

the pumps

is

taken

through

the ignition

fuse.

Faulty Opcration

of Pumps.

This would

_

cause-

failure,

or

shortage,

of

fuel

supply

to

the

carburetter,

and

may

be

due to

one

or

moie

of the

folowing"c"oter:-

r. Shortage

of

fwel

in-.the

tank.-This

should

have

caused

the

green

warning

lamp

to light,

but

if

the tank

has

been

allowed

to run

dry,-.the pumps

will

tick

continuously

and noisily.

On severe

gradients.

and

side

slopes,

these

symptoms

may

occur

before

the tank is

completely

empty,

due to

surging

of

firel in

the tank,

which

may

uncover

the

suction

pipe.

z.

Air

leak

on

the

suction

side.-Either

at

the

filter

or

on

the

pipe

lin_e.

A

slight air

leak

will

cause

the

pumps

to

work

rather.

faster

than

normal,

but

if _sufficiently

bad

to

tause

a

complete

air

lock,

the pumps

will

tick

continuously

and

noisily

as if

short

of

petrol.

t.

ruy-tf

aal,aes

not se.ating.-

Thg

delivery

valves

do

not give

any

easily

detectabl_e

signs

of

their

functioning.

If a

sucti5n

valvt

is

not

seating,

the pump

will

tick continuo-usly

when

the engine

is

switched

on

but

not

running.

I!

is pro6able

that

forEign

matter

is

lodged

under

one

of

tlie valves.

If the above

is

suspected,

remove

the

caps

,(3,

Fig.

11

),

the

valves

and

valve

cap assemblies

may

their

ni: titte?

oui

and

clgned.

4.

sl,uggish

operation

of

the

pumps,-check

that

the

electrical

connection

and

cont-act

-points

-are
clean

and in proper

order.

Jerify,.by-

alternately

disconnecting

the

pipes

"t

th"

unions,

that

it is the pump,

and

not

due

to a utoct<aee

in

the

pipe

line.

If with the pipes-disconnected

the

pumps

stfu

work

slufgishly,

the unit

should

be

removed

and

returned

to

Messrs.

E"entltiy

Motors

-(rggt)

Ltd.,

or

one

of their

"special

Retailers"

for

overhaul.

Tnr

Furr

Sysrnu.

Note--The

pumpswill

not

work

with both

petrol

pipes

disconnected;

in such

circumstances,

the pumps

m'ust

be earthed

to

the

chassis

frame.

Fuel

Tank.

Every

-zo,ooo

miles, as

directed

on

page

34,

the drain

plug

at

the

bottom

of

the tank should

be released.

It

is

not

necessarv

to remove

the

plug. It need

only be unscrewed

a

turn or

two, and

musl

afterwards

be securely

retightened.

This will flush

out any

accumulation

of

sediment

or water.

Fuel Fitters.

The

rear

filter, shown in

F'ig. 12, is provided

with

two

circular

gauzes,

located

above

a large

settling sump.

Fuel passes

upwards

through these

gauzes,

and

dirt settles on

their lower

faces

and-

in

the

sump.

The

filter

should be

cleaned

every

2o,ooo

miles,

as

directed

on

page

34.

47

1.

Body.

2.

Cover.

3.

Cover

nut.

4. Yoke.

Fie. 12.

REAR

FILTER.

When refitting

the

cover,

care

must

be

taken

that

the

cork

washer

is

sound,

and

properly

in

position,

and

the

nut

(3,

Fig. 12)

tightly

screwed

up.

Any

leaks

on

this-

the

suction

side

of

the

pumps

--

although

they

may

not

be

apparent

by

leakage

of

fuel,

will

impair

the

proper

functioning

of

the purnps

by

admitting

alr.

In

addition,

a

small

gavze

filter

(8,

F-iS.

14)

is

arranged

on

each

car-

buretter.

llhese

should

be removed

and

clea,ned

every

zo,ooo

miles

as

directed

on page

34.

Removal

is

effected

by

unscrewing

the

two

llio!

nuts

(1,

Fig.

13).

The filter gauzes

can

then

5. Outlet

pipe.

6. Drain

plug.

7.

Inlet

pipe.

be

removed

and cleaned in

petrol.

When

refitting-the

parts-,

care

must

be

taken

to replace

each

gauze

with

its

open

end outwards and

that the

aluminium

loint

wishers

are

in

position

on

the

unions.

48

TnB

'R'

TypB BBNrrBv.

Fuel

Gauge.

T-rr: $.t

gauge

registers

when

the

master

and ignition

switches

are

rrOn".

As

mentioned

on

page

43,

this

gauge

also registers

the amount

of

oil

in

the

engine

sump,

when

the appropriate

sriitch is

depressed.

The

Ganburetters

(Action).

Two carburetters

of

the

conventional

S.U. type are

fitted

as

sfrown-in.Figs.

13

and

14,

one

being

shown

in

section to illustrate

the principal

parts.

This

lyp.

of

carburetter

automatically

adjusts both

its choke

and

jet

area

in

accordance

with the

demand-of tire

engine as

determined

bv

.th9

degree

of

throttle

opening,

the

engine

spted, and

the load

against

which

the

engine

is

-operating.

Fie.

I3.-CARBURETTERS

lN POSITION

ON

ENGINE.

1. Fuel inlet

and filter,

2. Air

valve

chamber.

3. Hydraulic

piston.

4, Soienoid.

5. ldle Adiustment

screw.

This is

effected

by

using

the

manifold depression

to levitate

a

piston

or

air valve

carrying

a tapered

needle

which

regulates

the

fuel

p-ass_age.

Tfre, uppgr

side

of the piston

is connected by passage

ways

to

the

base

of the piston

facing

the throttle

valves, and

is thus

subject

to the

$epression

in

the

thiottle

body.

As the

air flow

through

the carburetter increases,

so the

depression

b_etwe.en

the

piston

and

the

throttle valve increases, therebytausing

the_piston

to

rise

and

admit

more air, and

consequently

the

needle

to be

withdrawn

from

the

jet,

thus

allowing

inore

fuel

to

flow.

Similarly,

as

thg

air

flow

falla, due to

reduced engine

requirements,

so

the

piston

fallg, maintaining

a

state of

balance wherebythe

piston

keeps

at a

certain height,

dependent on

engine

speed

and

thlottle

opening.

An approximately

constant

air velocity,

and

hence

an

TnB

TuBr

SvsrBu.

49

approximately

constant

degree

of

depression,

is

maintained

in the

region

of the

fuel

jet,

even

under

idling

conditions,

and

so

obviates

the.

necessity

f91 a

separate

idling

jet.

A

single

jet

only

is employed

in the

carburetter.

Automatic

Ain

Valve.

. .

The top

portion

of

.the

guide-spindle

cqrying

the

air

valve piston

is hollow,

torming

_a

well

surrounding

a small

siationary

damper

fiston,

suspended

from the

suction

chamber

cap by

meani

of

a^rod.

Th;

hollow

interior

of

the.

spindle

contains

a

quantity

of

thin

engine

oil,

.

and

the slight retarding

efiect

upon

the

movement

of the

alr valve

assembly,

occasioned

by

the resistance

of this

small

piston,

provides

the

momentary

enrichment

desirable

when

the

thro^ttle

is ibruptly

pPendd.

The

damper piston

is

of a

composite

construction

and

offers

little

resistance

t9

the passage

of the

oil during

the

downward.

move-

ment

of the

main piston.

EygTv

-mo1th,

as

directed

on p-agg

3o,,

the oil

reservoir

cap

nut

(8,

fig.

tef

should

be

unscrewed

and

the plunger

withdrawn,

lreat

cir,re

bging-lafen

to aaoid

damage

to the

plwngir

rof,by

bending;

the"reservoir

should

be

topped

rp,

if required,-with

the

rec-ommend"ed

oil,

so as

to

maintain

the level

of

the oil

to-the,top

of

the guide

rod

otrty.

The

plunger

slou,l$.then

b9

replaced,

taking

care

th.-at

no

dirt of grit

is

present.

-A

slight

steady pressur.e

may

6e

required

to

displace

t-he

oil

sufficientl5z

to allow

the

engagement

of the

thread

of

the

bil reservoir

cap nut.

If it

is

suspected

that

the automatic

air

valve is

not

working

c.orrectly,

the air

intake

should

be

removed,

and

a

check

made

b!

lifting

the

piston

with

the fingers,

when

it

should

be

noted

that

thb

piston

falls quite

freely

on

to-its

seat

when

released.

If any

sticking

or

sluggishness

il

apparent,

it

wil be

necessary

to

dismantle

the air

valve assembly:

firsl-Iglr.'ovq

the hydraulic

piiton

damper, next

remove

the

three

sciews

and

lift off

the

aiivalve

chimber

(1,

Fig.

14). The

piston

valve

can

then

be lifted,

oat,

the

utmost

care

being-taken

n_ot to

-bend

or damage

ct: depeyding,needle

aal,ae

(2,

Fig.

14),

or

to

bruise

the aal,ae

iry

?ny

uai.

The

valve,

dhamber

and

goid"

Jtroutd

b,e carefuttv

yry{_yit-h

a

pi6ce

of

clean

cloth

dipped

in"petrol,

and

the

piston

rod

ONLY

lubricated

with

a few

dropj

bt

tnin

bit.

,No

Pol'ishing

paste

or

abrasiaes

shoulil

be used

to

cl,ean

the

ual,ae

or

aalae

chamber.

TheSuction

disc

(5,

Fig.

14)

does not

touch

the

walls

of the

valve

chamber,

there

bping

p.

sm.all

clearance,

and

it is

centralised

solely

pf

tft. piston

rod

worklns

]tr

the guide.

Therefore,

any

sluggishneJ-s

in

movement

is

probably-due

to

dirt in

the guide,

br"on

ih"e

valve

chamber

walls.

,

When

replacing

the

valve,

it

will

be

noticed

that

there

is

a slot

wtrich.must

eng-age

a

tongue

provided

on the

carburetter

body.

The

air valve

chamber

can

orqly be

replaced

in

one

position,

th6 three

screw

holes

being

unevenly

spaced

to

ensure

thij.

5o

TnB

'R'

TypB Bnr.Irrpy.

Air

valve

cylinder.

Oil cap

nut.

Hydraulic

damper piston.

Piston

guide

rod.

Suction

disc.

Piston,

air

valve.

7.

Needle

valve.

8.

Fuel

inlet

and filter.

9. Float

chamber.

10.

Cap

nut.

11.

Mixture

adjustment

screw.

12.

Throttle

valve.

If

the above treat-

ment does

not effect

a

cure, the fault

may

be

due to

a

bent

jet

needle or alter-

natively to

the

needle

fouling

the

jet.

If

this

is

suspected, it

is

recommended

that

communication

is

made with

Messrs.

BentleyMotors

(rgSr

)

Ltd.,

or

one of

their

"Special

Retailers".

The

needle

valve

is

secured

in

position

by means

of a

grub

screw, and if it

should

be

necessary

to

remove

this,

0s,

for

instance,

when

re-

placing

an accident-

ally

damaged

needle,

it

must

be particular-

ly

noticed

that the

location

of

the

valve

is

determined

by a

shoulder.

The

valve

should

be

pushed

into

the

piston

until

this shoulder is

just

flush

with

the lower

face

and

the

grub

screw

tightened.

Xb-to

Fig.

14.-CARBURETTER-EXpLODED

VtEW.

1.

2.

3.

4.

5.

6.

If

a needle

should

be

accidentally

darnaged,

a

new

one

must be

obtained

from

either

Messrs.

Bentley

lVlotori

(iqst)

Ltd.,

or

one of

their "Special

Retailers".

Code letiers

ar"

st)rm"p.d

on the

end

of

the needle,

denoting

the

needle

characteristics,

and

it

is

essential

that

only

one of

the

same

coding

is

fitted.

Throttle

Gontrol.

.

The

gyantity

of

mixture

for

slow

running

is determine,il

by

means

of

.T $igstaule

screw

stop

on

the

front

"carburetter

(b,

fis.

19)

which. limits

the

closing

movement

of both

throttles.

'

This" is

16

adjusted

that

the

engine

will

idle

slowly

but

reliably

when

the

accelerator pedal

is

released.

no

hand

contiol being

provided.

Tnr Furr

Sysrnu.

Automatic

Choke Gontrol.

The

automatic system

consists

of:-

(i) Al

out-of-balance

butterfly

rqln.

-in

the

common

air

intake

pipe, indirectly

coupled

to

a diaphragm

which

is

subject

to

induction

pipe

depression.

(ii) A small

electro-magnet

wired in parallel

in the

ignition

circuit,

which holds

the butterfly

closed

when

starting.

(iii) A cam

for

"fast

idle",

loose-coupled

to

a pick-up

lever

con-

nected to

the butterfly

valve

spindle.

(iv) A

thermostatic

spring

unit

housed in

a

suitable

recess in

the

water

jacketing

of the

induction

manifold.

As the

engine

cools, the

thermostatic

spring

also

cools,

and

gradually

gains

tension.

The thermostatic

spring

is, however,

unable

to close the choke

valve until

the

throttle

stop

screw has been

lifted

from

the

fast idle cam.

,

It i; theryfore

necessary

to depress

the accelerator

fedal

slightly

and

then

allow it

to return

to its normal

position

be.fore

attempting

to- make

a

start.

on

releasing

the accelerator

pedal,

the throttle

opening

is

greater

than that

{or

normal

idling, by

virtue of

the extra.

stop

resting

on

the

"fast

idle"

cam.

When

the ignition

is switched

on, the

electro

magnet

wired in

parallel is energised

and the

armature

on the

butterfly

spindle

holds

the choke valve

in the

closed position.

On starting

the engine,

the

valve

is

held closed

until the

oil pressure

builds

up to a pre-determined

value to operate

the oil pressure

switch and

so release

the

choke valve

to take up its normal

open position.

As soon as the

engine

is running,

the

depression

created in

the

induction

pipe

is

exerted

on the

diaphragm

which

transmits

its energy

to the loose lever

on the butterfly

spindle.

This

in turn

catches up

on a peg and

turns

the spindle

to open the

butterfly

valve a

pre-

determined

amount,

against

the loading

of the

thermostatic

spiing.

Assuming

that

the accelerator

pedal

has

not been

moved,

the

engine will

continue

to run at

a speed

determined

by

the

starting

position

of

the

"fast

idle"

cam.

The engine coolant

jacketed

pocket

holding

the thermostatic

coil units

will

gradually

warm up and

transnit heat

to the

coil.

This in turn

will wind

up

and

gradually

release

the load

on the butterfly,

which will

gradually

open.

With the

depression

of

the accelerator

pedal

for

the

drive

away,

the

"fast

idle"

stop on the

throttle shaft

will move

away

from

the cam

and the

cam will fall

on to the

pick-up

lever

coupled

to the butterfly

spindle.

The loading

of the thermostatic

spring and

the off-set

of

the butterfly

have been

so

arranged

that any

air flow

greater than

thlt

^required

for

a

"fast

idle"

automatically

opens the butterffy

sufficient

for

engine requirements,

5r

52

Tur

'R'

Tvpr BeNrrBY.

Float

Feed

Mechanisms.

These

are

of

the usual

"top

feed"

pattern,

whereby,

as

the level

of

the

petrol

rises in the

float chamber, a

lever bearing

on the

top

of

the

float

moves

the conical seat

"needle"

upwards

on to its

seating,

so shutting off

the supply.

If

it

is

required to dismantle

the

float chambers, it will

be

more

convenient

to remove

them bodily-after disconnecting

the fuel

pipes,

and the small air

bleed

pipe

to the

cover-by unscrewing

the hexagon

plugs

which secure

each to

their respective carburetter

bodies.

When

the

covers are

removed,

care must

be taken that

the fulcrum

pins

of the

levers

do

not fall out.

They

are normally

retained by

means

of the walls of the

float chambers.

The

chambers should

be

wiped out with

a

piece

of clean wash-

leather before being

refitted.

When

replacing

them,

care must

be

taken

to

see that

the

packing

washers

are in

position,

one

above and

one

below the

boss

which couples each

to

the

carburetter

body.

Furthen Dismantling of

Garbunetter.

It should

never be

necessary

to remove

any other

parts

of

the

carburetter

than

those referred

to in

the foregoing pages.

The

jet

assembly securing nut should not be

disturbed,

as the

refitting

of this requires special tools to

ensure

that the

jet

is

accurately

centralised

relative

to

the

taper

needle valve.

Adiustment of

Gontrols.

There

should be

no necessity for any variation of the

adjustments

as

fixed

by the

makers.

Great care is taken during

the

testing of the

car

to

secure

the best settings, and these should not under normal

circumstances

be altered.

There

are certain

external adjustments,

however,

which are dealt

with in

the following

paragraph.

Setting of

ldling

Adjustments.

r.

Jhe

quantity

of mixture for

slow

running

is determined by

means

of an adjustable screw

on the

front

carburetter

(5,

Fig.

13)

which

limits the closing

movement of the s5rnchronised

throttles.

The

strength

or

quality

of the

mixture

for slow

running

is set

by means

of an adjustable

screw

in

the base of each

carburetter

(11,

Fig.

14).

The screw

operates

to

raise

or

lower

the

jet.

Raising

the

jet

causes the taper

needle

to sink

farther

into the

orifice,

so

weakening the

mixture.

Conversely,

lowering

the

jet

enriches

the

mixture.

TnB FuBr

Sysrru.

53

3.

Remove

the caps

(10,

Fig. 14)

from the

base of

each

carburetter

to expose.adjusting

screw (1

1,

Fig.

l4).

\4/ith

the

engine

warm

and

runnTg,

Inrrtipulate

the

screws;

.a

coin providei

an

easy

qe?_ry

of.

turning3

so that

the

engine

runs

regularly.

Any

sigir

of

"huntitrg'l

is

due

to

too rich

a

mixture,

ana

on-e

or both

"of

the

screws

should

be

screwed

farther

in.

on

the

other

h*9,

irre_gular

fi1ing,

indicated

by

irregular pulsations

from the exhaust pipe,

shows

the

mixture

to

be

weik,

"id

one

or

both

of

the adjusting

screws

should

be

screwed

out

a fiftle.

The correct positions

having

been

found, replace

the

screw

caps

arld

sealing

washers.

Air

Cleaner

and

Silencen

(Standand

Type).

A

cleaner

is

provided

within

the

front

end of

the

air

silencer

to

prevent

the

passage

of

dust

and grit

to the

engine.

Fig. 15.-AlR

CLEANER-STANDARD

TypE.

The cleaner

comprises

a composite

steel-wool

element

through

which

the

air

passes

on

its

w-ay

toihe

carburetter.

It is removed

6y

unscrewing

the

yrng-nut

in

thi

centre

of

the

ind

cover and

removin!

the

cover;

the

element

may

then

be

withdrawn.

- ,Every

ro,ooo

miles,

unless

the car

is being

operated

under

particu-

tqlv.d:rclv

conditions

when

the

cleaning

muit

6e

carried

out

it

5,ooo

miles'

intervals

or ev_en

!esg,

dependinglupon

the

dust

concentriiioi,

the

cleaner

element

should

be

rdmovedan?l

carefully

washed in

petroi

of paraffn,

and

afterwards

oiled

with

eneine

oil.

It

shsuid be

thoroughly

drained

before

refitting.

v

54

TnB

'R'

Typn

BBrttrBy.

Air Cleaner

and

Silencen

(Oil Bath

Type).

Fig.

16.-AlR

CLEANER-O|L

BATH

TypE.

1.

Filter

bowl

retaining

screw.

2.

Filter

bowl.

The air

cleaner

is

of

the

"oil

bath

type",

which

operates

very

efficiently

to

remove

the

dust

from

the

air

drawn

into

the

carburetter.

As

this

type

of cleaner

ac-

cumulates

considerable

dust

and

clirt it requires

regular

cleaning

every

r,ooo

miles,

or

more

often

according

to the

prevailing

conditions,

the

frequency

being

more

readily

determined

by

experience

in the

territory

in

which

the

car

is

operated.

As

directed

on

page

3o,

the

filter

element

should

be

removed

bv

unscrewing

the

lon"g

bolt

(1,

Fig. 16)

which

passes

through

the

top

of the

silencer.

The

oil

container

should

be

emptied

and

carefully

cleaned,

the

filter

element

being

thoroughly

washed

in petrol

and

Jtto*"a

lo'dry.

Replace

th-e

element

and

refill

the

oil

container

with

engine

oil to

the

indicated

level,

and

refix

in

position.

Page 55

BLANK

PAGE

Tsn

'R'

Typr BrNrrBy.

Tsn BneKrNG

Sysrnu.

57

CHAPTER

VI

The

Braking

System

General

Description-Possible V

ariations-Adjustments-Adjustment

of Hand

Brake-Adjustment

of Seruo-I.ubrication-Bleei,ing

the

Hydraulic System-Hydrawlic

Master Cylinder.

Generat Description.

The

Bentley four-wheel

braking

system

is

of the

Servo assisted

type,

and comprises a

mechanically driven

servo

motor

of

the dry

disc-brake

type,

which

is

equally effective for

either forward

or

backward

movement

of the

car. Further,

even should

the servo be

out of

action,

the

rod

operated

rear

brakes

are still directly

coupled

to

the

pedal.

Pressure on the

pedal

applies the rear brakes

direct

in

the usual

manner,

and also

engages the servo, but

the front brakes

which are

of

the

hydraulically

operated

type are actuated

entirely by the

servo

acting through the

medium of a balance lever and hydraulic

master

cylinder.

The

servo effect is

distributed between

the front and

rear

brakes,

being

added therefore

to the direct pedal

effect

in

the case of

the

rear brakes.

With the leverages provided,

this results in about

55

per

cent. of the

total braking

being

imposed

on

the front

wheels, which

allows for the

fact that greater

weight is

thrown

upon

the front wheels

during

braking.

The

proportioning

of the servo

pull

to the front and rear brakes

respectively is

effected by a balancing

lever. A separate

equaliser

is

provided

for

the two rea.r

brakes, which,

with the

hydraulic

operation

of

the frqpt

brakes,

ensures

even

braking

on either

side

of

the car.

The

hand

brake

lever

operates the rear brakes

only and uses

the

same linkage

as the foot

pedal.

A diagrammatic

representation

of the whole system is

shown

in

Fig.

17.

A

pull

rod

(1,

Fig. l7), operated by

the

pedal, is

coupled

to a

lever

(2),

on

the servo

motor shaft,

the

motor

itself (3)

being mounted

on the

off-side

of

the

gearbox,

and

driven

at approximately.one-tenth

of

the

propeller

shaft speed.

58

TnB

'R'

Tvpe BBnruBv.

The

lever

(2) has

inclined cams

formed

on the

face of

its boss,

these

cams

engaging,

through

the

medium

of steel

balls, similar cams

formed

on the

boss

of

another lever

(4). From

the latter

a

rod (5)

directly

actuates the

rear brakes

through

the

medium

of the

levers

{6)

and

(7),

which are

pivoted on

a bracket

bolted

to the

"X"

member

of the

frame, and

finally,

through the

rear

equaliser

(8)

mounted

on

a

bracket

suspended

from the

axle.

The

output

from the servo

is

taken

by one

of

the

two

rods (9),

according

to

whether the

car

is moving forwards

or backwards, to

the

lever

(1O). This

lever carries,

in

turn,

a balance

lever

(1 1), the lower

end

of

wtrich

is connected,by

the

rod (12) to

the rear brake

lever (7),

thus

augmenting

the direct

pedal

effort, while

its upper end

is

coupled

to the master

cylinder

(13), which

actuates the

front brakes.

'flic

dashboard

hand brake

(14),

is

mounted

under the

facia board,

convenient

to

the driver's

right hand.

The

ratchet

release is

so

arranged

that

should

it be inadvertently

knocked

or

pressed, the brakes

will not

be

released. In

order to

release the brakes,

the

trigger

must

be

fully

depressed

and held

in

this

position.

The

hand

brake

is

then

pulled,

"rif

"pplying

the

brakes, arid this

action frees

the

ratchet

permitting

the

brakes to

be

released,

provided

that

the trigger

is

still

held.

This

device

is particularly useful

in preventing accidental

release of the

brakes

when

the car

is parked.

To

obtain

this action,

the trigger

is not directly

connected

to the

ratchet

pawl, but

cornpresses

a

spring.

This

spring,

in

turn,

operates

the

pawl, but

is

only strong

enough to

move

it out of engagement

when

the

load has

been removed

by pulling on the

hand brake.

The

hand

brake

is

connected

by an enclosed

cable

(15),to a hori-

zontal lever

(16),

mounted on the

"X"

section

of the

frame which

provides the

required

leverage, and

is

in

turn

coupled

to

the rear

brakes,

through

the levers (7)

and (17)

and

the

rear equaliser.

The

same

rear brake-shoes

are used, therefore,

as for

the

pedal operation,

and the

application and

release of the

hand

brake

can

be

lightened

accordingly

by simultaneous

application

of the

foot brake.

Poseible

Variations.

As

already mentioned, the leverages

are

so

proportioned

that

the

total

braking

effort is distributed

in a

predetermined

ratio between

the front

and

rear brakes.

This

distribution will

be upset if the servo

brakes

are

allowed

to

become badly

out

of

adjustment, or

if

the

seivo,

for any

reason, fails

to

give its correct

output.

A less likely cause

would

be

oil or

grease

on

the brake linings.

The

need for

adjustment of the

rear brakes

will be

indicated

by

excessive travel

of

the hand

brake lever,

whereas

the front

brakes,

which

are

operated

by

the

servo

motor

only,

will

not affect

the hand

brake

or pedal

travel.

TUB

BnaKrNG

SysrBu.

59

-

It is unlikely,

however,

that

the front

brakes

will wear

more rapidly

than

the

rear

brakes,

so,

provided

that they

are adjusted

whenever

adjustment

of the rear

brakes is

required,

no

trouble in

this

respect

need

be expected.

Low or

inconsistent

output

from

the

servo worrld

be indicated

bv

heavy or non-progressive

brake pedal

action,

together

with insufficieni

{ront

braking, in

which

case

the

servo

would

have

to be

dismantlecJ

to ascertain

the

cause

of

the

trouble.

As

this is

a

delicate

operation,

it

is

recommended

that

Messrs.

Bentley

r\Iotors

(r93r)

I-td.,6r

one

of

their

"Special

Retailers"

be

entrusted

with

this

work.

+ .light

pedal

acLion,

accompanied

by

defective

front

braking,

resulting

irr

the

rear

wheels

locking,

would

indicate

a fault

in

the

froit

braking

system.

An

excess

of front

braking

would indicate

a fault

in

the rear

brakes.

In

the

unlikely

event

of oil reaching

either

of

the rear

brakes,

the

self*seal

bearing

on

the rear

axle half

ihaft

will be

at fault.

Grease

catchers

are _ provided

for

the front

hubs,

and provided

that

the

recommen{ed-grease

lrg

used

and

the quantity

fimited

to r}

ozs.

in each

hub,

this

should

not

be able

to

relch

the brake

linings.

Adjustments.

A separate

adjustment.

is_ provided

on

each

brake

carrier plate

to-.compensate

for

wear

of

the brake

shoe

linings,

and is

the^only

adjustment

provided

on

the

whole

system.

.

It is important

to note

that in

no

circumstances

should

adjustments

be

attempted

at

anlr.other

point,

for instance,

by

altering

the

lengths

of the

brake

rods.

These

are all

carefully

determined

du"ring

"t..iion

of the

chassis,

with

a

view

to

synchronisation

of

the

front"and.

rear

safety

stops,

which

ensure

that in

the

event

of failure

of any

part

of

the

system,

at

least

one pair

of brakes

will remain

available.

The

method

of adjustment

is

the

same

for

both

front

and rear

brakes,

with

the

exception

that

a

hand

wheel

is provided

on the rear

brake

adjusters,

while-

a

|"

B.S.F.

open-ended

tpa.rn..

must

be

used

*

tI:

sq-uaned

end

of

the

front

prake

adjusters'.

The

rear

adjusters

(2-,.

Fig. 19)

a1e

located

forward

of

the

-axle
tubes,

and

the front

adjusters

(1,

Fig.

18)

directly

below

the

steering

pivot

pins.

For

each complete

_toln

of the

adjusters,

four

"clicks"

will be felt,

and

betiveen

eaih

"click"

the

brake

shoes

are

expanded

towards

the

drum

approximately

.gr4u,

and

then

moved back

.oro", giving

an

incremental

adjustment

of

.oo4",

and

a running

clearance

oi

loto{

To adju_st

t_he

brakes,

rotate

the

adjusters

in

a

clockwise

direction

until

considerable

resistance

is felt.

This resistance

must

be

equal

for

all four

brakes,

and

should

the

last

"click"

on

any

one

adjuster'require

noticeably

-greater

force

to

obtain,

the

adjuster

shouid be

tuined

back

to

the previous

"click".

This

will

-give
the

correct brake

adjustment.

6o

Trn

'R'

TypB

BBNrrBy.

It

is

not

necessary

to

jack

up

the

car to adjust

the brakes, as

the

adjusters

are

so

designed

to

give

the correct-shoe

clearances

auto-

matically.

-

If, after

long

service,

the brake

linings

require

renewal,

this will

be apparent

by the

adjusters

coming

to the

eird

of their

travel, and

will

have

a solid

feel quite

distinct

flom

the resistance

felt

when

the

brake

shoes are

correctly

adjusted.

Fig. 18.-FRONT

BRAKE

ADJUSTMENT.

a

1, Adiuster

screw.

2, Hydraulic

pipe.

3. Bleeder

connection.

Fig.

i9.-REAR BRAKE ADJUSTMENT.

. 1. Brake drum..

2. Adiuster screw.

Adjustment

of Hand Brake.

Adjustment

of the rear

brakes

takes up both the

pedal

and

hand

brake

clearance in

the same

operation. No other

adjustment is required.

Tun

BneKrNG

Sysrnu.

Adjustment of

the

Servo.

The

servo

is

of

the

dry disc-brake

type, and

is

shown

in

Fig.

17.

An adjustment

is

provided

for the initial

setting and

wear

of the

friction

surfaces,

but

once correctly

set, should

require

no further

attention for

a considerable

period,

as very little

wear

occurs.

As

the

operation

is

of a

delicate

nature

it is

advised that

this adjustment

should be

effected by

Messrs.

Bentley

Motors

(r9Sr)

Ltd., or

one

of

their

"Special

Retailers".

Lubrication.

The

need for hand lubrication

of various

parts

of the

mechanism

has been reduced

to a minimum,

by

the

use

of selflubricating bearing

bushes

at the fulcrum of

practically

all levers.

The

only

points

that

require attention are

the

jaws

and pins

of the

pull

rods and intermediate

levers

(6, 7

and 17, Fig. 17).

Oil

should be

applied

to these

points

every

5,ooo

miles,

as directed

on

page

3r.

The

ball bearing cams

which

actuate

the servo

(as

described earlier

in

this chapter) are filled with lubricant upon

initial build,

and require

no attention

between overhauls of the chassis.

6r

1.

2.

Fic.

20.-THE

HYDRAULIC

MASTER

CYLINDER

AND RESERVOIR.

Filler

plug.

3. Pin.

Master

cylinder and

reservoir.

4,

Support bracket.

Bleeding

the

Hydraulic System.

Bleeding, that

is

to

say expelling

air from

the system, should

only
be necessary when com­pletely

recharging the

system with

fluid fol-

lowing the

removal

of

a

component

or

the

disconnection

of a

pipe

joint.

Undernormalcon-

ditions

air

does

not

enter

the system

as a result

of brake application.

To

bleed

the system,

proceed as

follows:-

r.

Attach a clean

rub-

ber

drain

tube to

one

front brake

bleeder

screw

(3,

Fig.

18),

and

immerse the

other

end

in

a clean

glass

j"t

in which

there

is sufficient

hydraulic

brake fluid
to submerge the end
of

the

tube.

6z

TnB

'R'

TypB

BnNrrny.

z.

Release

the

bleeder

screw (3)

half

to

one

turn.

3.

Remove

the filler

plyg

(1,

Fig.

20)

and

fill

the reservoir

integral

with

the

master

cylinder,

with

the recommended

fluid.

is..

page

28.)

4.

Push

the

joint.{orward

until

the extended

pin

(B)

abuts

against

the

master

cylinder

support

brackets

(a).-

5.

Release,

plusg

slightly,

and

repeat

until

the reservoir

is

nearly

empty,

but

taking

care not

to

empty it

completely.

6. Tighten

the

bleeder

screw

and

transfer

drain

tube

to

the other

front

brake.

'

7.

Refill

the reservoir

and

bleed

this

brake

in

a

similar

manner.

8.

Finally,

refill

the reservoir

and

replace

the filler

prug.

Hydraulio

Master

Cylinder.

The fluid

level

in

the master

cylinder

should

be examined

every

ro,ooo

miles,

as

directed

on page

33,

and

topped up

if

necessary

so

as

to

maintain

the level

at

one

inch

below

th-e fillei

cap.

A

rapid

Jall

in

the

fluid

level

indicates

a.leak

at

some point

in the

system, and

must

be

traced

and

rectified.

GBennox,

PnoeotrBn

SneFT

AND

Rnen

Axrp.

63

CHAPTER

VII

GearboX, Propeller

Shaft

and

Rear

Axle

'

The

Gearbox-(Jniaersal

Joints-Rear

Axle.

The

Gearbox.

With the automatic

gearbg*,

no

clutch

or

clutch

pedal

is necessary.

Speed..c\a1se

ranges

are

effected automatically,

the

timing beirig

controlled

by the

automatic

control

unit,

and

is

a functior

of

the

vehicle

speed

and

the throttle opening.

Fluid is inserted

into

the

gearbox

by

removing

the dipstick

shown

at 2,

Fig. 21.

Recommended

fluids

are

given

on page

27.

The oil level

should

be inspected

every month,

as

directed

on

page

30.

Fig. 21.-GEARBOX

ACCESS

POINTS.

t.

2.

3.

Cover,

dipstick.

Dipstick.

Cover,

brake band adjusters.

4.

Front

band

adjuster.

5. Rear

band

adiuster.

64

TnB

'R'

TypB

BpNrrBy.

___. Eor_

topping

up,

the following

procedure

should be adopted:-

With the

control

lever

in

neutral,

the engine should be allowed

to

run

for about

three minutes

before

the

fluid level

is checked.

This

should

be

done

while

the engine

is

still

running.

Fluid

should then

be added

until

the

level

reaches

the

mark

on

the dipstick, taking care

that

the

box

is not

overfull.

Every

zo,ooo miles,

the oil

should be

drained

from

the

gearbox

and

fluid

coupling.

The

drain

plug

on

the

fluid

coupling can-be reached

by remoyitg

the

lower

cover

of

the betl housing (3, Fig.

22),

and

turning

the

engine

by means

of

the starter

motor-until

the

ptug is at

the bottom

position.

The

gearbox

can be

drained

by

the

plug in

the

sump

shown

in 2,

Fig. 22.

After

draining,

both

plugs

should

be replaced.

Fig.

22.-GEARBOX,

UNDERNEATH VIEW.

t. Gearbox

sump.

2.

Drain

plug.

3. Lower bell-housing cover.

4.

Timing inspection

hole cover.

To

refill, first

add

14 pints

of

the recommended

fluid.

With the

lrand

brake

on, start

the

lngine

and let it run for

several minutes.

Then

add

5

or 6 more

pints

of

fluid.

Ailow the

engine to run

for a

short

while and

then check

the

level by

means

of

the dipstick.

Gpansox,

PnopBtr,sn

SneFT AND

Rren

Axrn.

65

Univensal

Joints.

The

propeller

shaft

universal

joints

are fitted with needle roller

bearings,

and each

joint

is

provided

with a

grease-gun

lubricator

(3, Fig.

23),

located

at the centre

of

the

cross-piece.

1. sriding

joint.

z. o,".lt;il;i:L"'fft":::

sHAFr'

Grease nippre universarjoint.

The driven

portion

of

the centre

joint

is provided

with serrations

which

engage similar serrations within

the

propeller

shaft

to

permit

the necessary degree

of

telescoping

movement.

This sliding

joint

is

also lubricated by means

of a

grease-gun

lubricator, shown at (2,

Fig.

23). Every

ro,ooo miles, as directed

on

page

32,

the correct

grease

should be injected

by means of the

grease-gun into all

the

four

lubricators.

Rear

Axle.

The rear axle is

of the

semi-floating type.

The

final

drive

is

by offset

hypoid bevel

gears,

which

possess

the

advantages

of being silent in

running,

and,

owing to the offset

disposition

of

the

pinion,

of enabling a lower

body position

to

be

obtained without

decreasing

the

ground

clearance.

It

i9

important that no other

oil

than that

recontmended

shou,ld be

used

in the rear

axle.

(See

page

28.)

Every

5,ooo

miles, as directed

on

page

3r,

the level

of

the oil

should

be inspected,

and

topped-up if necessary.

Every

za,ooo miles,

as directed

on

page

34,

the casing

must

be

drained,

and refilled

with

fresh oil

to the correct

level.

The drain plug

(2,

Fig.

24)

should be

removed,

with the special

spanner provided,

preferably

when

the casing is warm; and

all

the

oil

allowed

to

drain out.

TttB

'R'

TvpB

BrNrrnY.

PIug

(1

)

may then

be

removed

for

filling

purposes.

One-and-three-

quartei (rf)

pints

of fresh oil should

be inserted,

using

a syringe.

This

quantity should

just

cause oil to overflow

from the

f,lling

orifice.

Fie. 24.-REAR

AXLE

CASING.

1. Filler

and

level

plug.

2.

Draiir

plug.

3. Breather.

Care

must

be

taken to

see that the

washer

is in

position

when

replacing the

phrg.

SrBonrNC,

SuOCx

Deupcns, ROap

SrRlNcs,

WnBnrs

eNn

TvnnS.

67

CHAPTER VIII

Steering,

Shock

Dampers,

Road

Springs,

Wheels

and Tyres

Steering

Box

and Column-Steering-Front

Suspension-Warning,

Front Swspension,

Springs-Steering

Arms and

Joints-Front

Stabiliser

-Rear

Hydraulic

Shock Dampers-Rear

Road

Springs-Wheels-

Wheel

Discs-Lwbrication

rf Wheel

Bearings-Tyres-The

Jacking

System-Wheel

Changing-Fitting

and

Removing Tyres-Inf'ation

of

Tyres-Balancing

Road, Wheels.

Steering

Box and Column.

The

steering

mechanism is of the

cam-and-roller

type, and requires

no attention

beyond

inspection

of the

oil

level.

The

cover of

the

box is

provided with

a filling

plug (2, Fig. 25).

Every

5,ooo

miles, as

directed

on page

3r,

this

plug should

be

removed,

preferably

when the box is warm,

and the

level of the oil inspected.

If

necessary,

oil

should be

poured

in until

it is on the

point

of

over-

flowing

from

the

plug

orifice.

F'or

correct oils,

see

page

zB.

1.

2.
3,

Steering

column.

Oil

filler

plug.

Gear

change

contrqf.

Fie. ZS.-STEERING

COLUMN.

4. Micro-switch.

5. Reverse light switch.

6B Tsn

'R'

TvpB

BrNrr.Bv.

Steering.

Experience

has shown

that

too

much importance cannot

be

attached to

proper

balance

of

the

front

wheels

and tyres.

As it is only

possible

to

balance the

wheels

and tyres statically,

this

does

not

eliminate the effect of slight

out-of-balance forces which

can only be

detected dynamically. Such a

condition

may

be

caused

by

the

normal

wear of the tyres on the

front

wheels; as

is inevitable

*itn

independent

front su,sfension, tyre wear

will be slightly less

regular than on the rear wheels.

Therefore, it is recommended

that

the front wheels should

be

periodically

changed

to the

rear

and vice versa to

even out the wear

of

the tyres.

Front Suspension.

Each wheel is indeperldently

sprung,

the

suspension consisting

of the two upper

and two lower radius arms

of different

lengths

set

at a leading

angle, between

which a vertical

yoke

is

carried,

and

on

this

the

stub

axles are pivoted.

The

upper radius

arms are

connected to and operate the special

Bentley

shock

damper,

which

eff ectively dampens excessive

spring

action.

The main helical

coil spring

is

mounted between

the

forward

lower

radius

arm and a

seat formed as an integral part of the chassis frame.

The

ball

joints

and

the

steering

pivot

bearings are lubri-

cated

from

the

central

chassis

system.

(See

Fig. 5.)

The

shock

damper

consists of

two

pistons

operatingin

cylinders

full of oil, the

oil being

dis-

placed from

one cylinder to the

other

through

drilled

passages,

the degree

of damping being

controlled

by spring - loaded

valves.

'

Until

it is obvious

that the

eflectiveness of

the

shock damper

has

become

reduced,

or undue

leakage

is apparent, no attention

whatever will

be necessary

for

ro,ooo miles, when the level of

the oil

in

the

shock

damper

should

be

inspected,

as directed

on

page

32.

It

is of vital

importance

that

only

perfectly clean

oil

of the

correct

grade

should be

used, and

Iine

gauze

before

using.

Fig.

26.-FRONT

SHOCK

DAMPER.

1. Shock

Damper.

2. Filler

Plug.

3. Hydraulic

Brake Pipe,

this

should

be strained through a

StnBRrNc,

Suocx

Deuprns,

RoAn SrnlNcs,

Wsnrrs

eNo Tvnrs.

69

Straining

is facilitated

if the oil

be first warmed to

about

75"C.

The

importance of the

above cannot

be

over-emphasised, as a

very

small

particle of

foreign matter

in

the

oil

may lodge under one of the

valves and

impair

the

effectiveness

of the shock

damper.

WARNING.

Front Suspension

Springs.

No

attempt

must

be

made

to remove the coil

springs

of the

front

suspenslon.

Special appliances are

required because the

powerful

springs

are

compressed

even

when

in

the

rebound

position.

Any

necessary

dismantling

or

adjustment of the suspension

must

be

effected

by

Messrs.

Bentley Motors

(rgEr) Ltd., or one

of

their

"Special

Retailers".

(See page 16.)

Steering

Arms and

Joints,

The steering

gear

should

be examined occasionally to see

that

all bolts are

tight and

joints

well lubricated.

If

any

of the nuts are found loose,

and only

retained by

their

split

pins,

the

latter

should

be

removed,

the

nuts

screwed

up

tightly

and

new split

pins

fitted.

The

ball

joints

of the cross

and

side

steering tubes are

lubricated

from the

centralised

chassis

system,

as

illustrated in

Fig. 5.

The

bearing

pads of all

joints

are

spring-loaded,

being self-adjusting

for wear. They

should

not

normally

require

attention

except

when

the

car

is

undergoing

a

general'overhaul.

Front Stabiliser.

In

order

to

check

any tendency of the car

to

"rol1"

on

corners,

a steel torsion-rod stabiliser

is provided at

the

front end of the

chassis.

The stabiliser

is

carried

in rubber bearings, and

is

coupled to

the

wheel

mountings

by links

with

rubber pads.

No attention

is necessary.

-

Rear

Hydraulic

Shock

Dampers.

Hydraulic shock dampers

of Bentley design

and

manufacture

are fitted to the

rear

axle, one

of the dampers

being

shown

in

Fig.27.

Unless

it is

obvious that

the effectiveness of the shock

damper

has

become reduced, or undue

leakage of

oil

is apparent,

no attention

will

be necessary for

ro,ooo

miles of

running.

After ro,ooo

miles,

it is

necessary to

inspect

the

oil level

in

the

shock dampers as

directed

on

page

32.

,

For

th.is

.p-ulgose

a filling

plug

(1,

Fig-. 27)

is

provided,

arranged

at

such

a

height

in

the casing

ls

tb

iontrol

the'maiimum

oil

level.-

It

is

of vital

importance

that

only perfectly

clean

oil

of

the

correct

grade

should

be

used.

The following

precautions

must be

observed.:-

r.

Before

attempting

to

remove

the

plug.

(l

),

both

the plug

and

the

shock

9q*pgr

casing

adjacent-to--it'must

be

cleaied.r.ry

carefully

with

a brush

dipped

in

paraffin,

in

order

to

avoid

thl

possibility

of

dirt

entering-the

hoie

when

the plug

is

removed.

z.

9"ly

a

recommended

oil

must be used

(see page

zB),

and

before

inserting

this, it

must be

strained

through

"

fittdg",tl..

Strainint

.

is

greatly

facilitated

if

the

oil be

firsi

*rr*"d

to

about

7s"i.

J'HB

'R'

Typn

BBurrBy.

Fig.

27.-REAR

HYDRAULIC

SHOCK

DAMPER.

Filler

plug.

2,

,,Ride

control,,

oil

piDe.

^

Thg,

importance

of

such

cleanliness

cannot

be

over-emphasised.

A

small

particle

of{oreign

matter

may

lodge

under

"

"ur".

""'a

dp;i;

the

effectiveness

of

the"sho.[-i"-p.i.

-(r- ----

SrnrnrXC,

SttocK

DaMpens,

ROlo Srntncs,

WnBnrs

aNo TvnES.

7I

The

plug

(1)

can then be

removed

with a box-spanner,

and

the

oil

level-restored,

if

necessary, to the

bottom

of

the

plug hole,

the

oil

being

poured in very

slowly to

avoid entrapping

bubbles

of air.

It

will

be

-found
most

convenient

to

add

oil by

means

of small

syringe

provided

in the tool

kit. When

replacing the

plug, care

must be

taken

that

its

washer

is

in

position.

The

shock damper

consists

of a piston assembly

operating in a

cylinder

which

is

maintained

full

of oil, the

latter being displaced

fiom one

end

of

the

cylinder

to the

other, past spring-loaded

valves.

The

loading

of these valves,

and

hence the degree

of damping,

is

controllable

through

the

rJRide

Control"

lever by

means of

a

small

pump carried in a

casing

bolted to

the

gearbox,

which

maintains

a

pressure

of oil in a

system of

piping. This

pressure

is

variable,

and

is

cohtrolled

through

a relief valve,

operated

by the aforementioned

lever.

The

pump

is charged with

oil

from the

gearbox. It must be

observed

that

oil

is not actually

pumped into

the dampers,

and

there

should be

no wastage

of

oil from the

pump

unit

or pipe

line.

Such

wastage

or

leakage

will

impair the

functioning

of the

control.

As it

is of such

importance

that

the

shock dampers,

and also the

pump

and

pipe line,

should be

maintained

full of oil, evidence

of

undue

leakage

should

be

at

once reported

to

Messrs. Bentley

Motors

(rqSr) Ltd.,

or one of their

"Special

Retailers".

(See page 16.)

Rear

Road

Spnings.

The

forward ends

of

the

rear springs

are

pivoted

to

the

frame by

means of

steel bushes.

The

shackle

pins

at the

front and

rear

ends

are

of the

threaded

type,

and

both bushes

and shackle

pins are

lubricated

from the

centralised

chassis system.

The

advantage

of threaded

bearing

pins is

that

they do

not

develop

end-play

as the

result

of wear.

The

springs

themselves

are encased

in leather

gaiters

and,

b5r

means

of a special

arrangement

of oil holes and

grooves

in the

leaves,

the ends

of

the

three

longest leaves

of each

spring

are

lubricated

by

surplus

oil

from

the

eye

of

the

master

leaf.

Owing

to this

arrangement,

in

combination

with absorbent

material

inside the

gaiter,

the

springs

are entirely

self-lubricating

and remain

free from squeaks.

Wheels.

All wheels are

of

heavy

gauge

pressed steel,

with

16"

by

5"

well-base

rims, and

are

secured

with five

nuts.

The securing nuts

for the

"off-side" or

R.H. wheels

have right-

hand

threads,

and

those

for

the

"near-side" or

L.H. have

left-hand

threads.

The

nuts must be tightened,

with

the wheel-brace

provided,

rlvenly

and securely,

and the threads

must be

kept clean and

greased.

72

Tur

'R'

TvpB

BrNrrev.

If any difficulty

is

experienced

in removing

the

nuts

with

the

wheel-

brace,

eitra

leverage

can be

applied

by using

the

l"

spanner,

provided

in the

tool

kit, on

the

squared

section

of

the wheel-brace

spanner

head.

Wheel

Discs.

When

fitting the wheel discs,

care

must be taken

to

get

the

valve

centred

in the

hole

provided.

The

outer

nuts, having right-hand

threads

for

both

"off-side

and

near-side"

wheels, are

neCessary

only to

retain

the

disc

and should

therefore

not be

overtightened.

The

correct

tension

is attained

by

giving

the

nut

one

complete

turn,

with the special

spanner

provided,

after the disc

has

been

felt

to

be

in light contact

with the

rubber stops

on the

wheel

centre.

There

should be a small

gap,

approximately

'roo",

between

the

edge

of

the disc

and the wheel.

Overtightening

distorts

and

brings

the

disc

into contact

with the wheel,

thus

causing

creaks

and

rattles.

Lubrication

of

Wheel Bearings.

The

wheel bearings

are

correctly

packed with

ball-bearing

grease

in the

first

instance,

and

should

need

no

attention

between

general

overhauls

of

the

chassis.

Tyres,

The

tyres

fitted are India

Super

Silent

Rayon, size

6.5o" by

t6'.

When

ordering

new

covers,

the

above

should

be specified.

With

regard

to

the

innel

tubes,

it is

necessary

to state

the size

and mention

"well-base".

Tubes

for

flat

base

rims

should

not be

used.

The

Jacking

System'

A

portable

jack

is

provided

in

the

tool

kit and

is operated as

shown

in Figs.

28

and

29.

Thq

jack

is

fitted on to a

slide

arranged

on

the side

frame member

near

the

centre

body

pillar,

and is used

either

side

of the car as

required.

To

operate,

pu.sh

the

jack

right

home on

the slide,

spin

the

body

of the

jack

to

the

ground, insert

handle

and

use

as

shown in Fig. 29.

It

is important,

before

operating

the

jack,

that

the hand

brake

is

pulled well on.

It

is

convenient

to note that the

jack

may

be

used

in

other

suitable

positions,

such

as

under

the

rear

springs

or

front

jacking

pad

if

required.

Srrrnrwc,

Sttocx

DaupBns,

RoAn

Srnlltcs,

WHrBrs

eNn

TvnEs.

73

Fie.

28.-FITTING JACK

TO

SLIDE. Fie. 29.*OPERATING

JACK.

Wheel Changing,

No

difficulty

should be experienced

in wheel changing;

the

spare

wheel

can be

put on the rear or front hub

with rzery

little effort

as

follows:-

Rean.-Having

jacked

up the car,

applied

the

hand

brake

and

removed the

rear wheel:-

r.

Roll the spare

wheel

under the

hub, the top of

the wheel

being

inclined outwards, then

with a foot at the

bottom

of the

wheel,

lift

by

the

rim

on to the

hub

extension,

as

shown

in

Fig.

30.

2. One

of the five wheel studs will

be found to

be nearly

on the

horizontal halfway line, either

to

the

front or

rear. Rotate

and

tilt the wheel

until

this stud

probudes

through

the

nearest

stud hole.

Fig.

3O.-MOUNTING

REAR

WHEEL.

Fie. 31.-POSITIONING

REAR

WHEEL.

74

Tun

'R'

TypB

BBNrr,Bv.

3.

Using the

one

entered

stud

as a

fulcrum,

raise

the

wheel

until

the

other

studs

enter

their respective

holes. (See

Fig.

31.)

-

Replace

wheel

nuts,

wheel

disc and retaining

nut as

previously

described.

Front'-Position

the wheel

on the hub

extension as

described

for

the rear

wheel.

(r).

(See

Fig.

30.)

r.

Rotate

the

wheel,

which

also rotates

the hub, until

a stud

enters

at

the halfway

line.

(See

Fig.

32.)

z.

Rotate

the

wheel

until

the entered stud is

at

the

top. when

it

will

be

found

that

the

other four will

go

home.

(see

nig.

3a.y

Fig.32.-ROTATING

FRONT

WHEEL.

Fig.33.-ENTERED

STUD

AT

TOP.

-

Replace

wheel

nuts,

wheel

disc and retaining

nut

as previously

described.

FITTING

AND

REMOVING TYRES.

Inextensible

steel

wires

are incorporated in

the

edges of the tyres.

Therefore,

do not

attempt

to stretch-

the wire

edges

of

the tyre cover

over

the rim

edge.

Force is

entirely

unnecessary,

and may be

dangerous, as it merely

tends

to damage

the cover

edgei

and serves

no helpful purpose.

--

Fitting

or removing,will

be

quite

easy

if

the

wire

edges are carefully

adjusted.into

the

rim

base;

if

if is not

fbund to

be

easy, the

operation

is not

being performed

correctly.

To

Remove

the

Tyne.

Remove

all

valve parts,

and

push

both

cover

edges

into

the base of

the rim

at

the part

diametrically

opposite to the valve,

then lever

the

cover

edges

near

the

valve

over'tfre rim edge.

SrBnnrNC,

Sttocx

Deupnns,

ROeo

SrntNcs,

WuBBTS

eNo

TvnES'

75

To

Fit

TYre.

Push

one

edge

of the

cover

over

the

edge

of

the

rim'

It

will

go

qoii"

"*ii/ir

tn?

p".t

first

put

on is

pushed

right

dowir

into

the

wheel

base.

A

coloured

spot

on

the

outer

wall

indicates-

its

lightest

part, and

the

cover

should^

be

fitted

so

that

the

coloured

spot

is

at

the

valve

position.

r.

Dust

evenly

with

french

chalk

both

the

inside

of

the

cover

and

the

outside

of the

inner

tube.

z.

Inflate

the

tube

until

it

begins

to

round

out,

then

insert

into

cover.

Mount

tyre.

Before

inflating,

make

sure

that

the

tyre

beads

are

clear

of

the

well

of the

iim

all

the

way

round.

5.

Inflate

slowly

until

thc

beads

are

fully

seated'

6.

Remove

valve

and

deflate

the

tube

completely'

7.

Refit

valve

and

inflate

the

tyre

to

the

oprrect

working

Pressure'

N.B.-This

procedure

must

be

followed

whenever

the

tube

is

refitted.

Inflation

of

Tyres.

The

pressures

recommended

for

the

6.5o"

by

r6"

India

tyres

are:-

z4lbs./sq.

in.

(r.6g

kgltq.

.-'l

) Cotd.

33

lbs./sq.

in.

(2.32

kgltq.

cm.)

J

Tyre

pressures

will

increase

slightly

uft"-t

continued

running

at

high'.p."dr

or in

hot weather.

It

is not

considered

advisable

to

reduce

f.?*rir"r

und.er

such

conditions,

as this

would

tend

to

cause

further

ireating,

due

to

excessive

flexing

when

the

tyre

cools.

The

pressures

being

comparatively.

low,

it

is important

that

they

should

b^e

carefulty

mJntainea

if

maiimum

tyre

life

is to

be

secured.

It

is,

therefore,

,6.o**ended

that

the

pressure

be

tested

weekly

by

means

of

a

gauge applied

to

the

valve

stem

orifice.

Balaicing

the Road

Wheels.

It is

most

important,

in view

of the

high speeds

attainable,

that

the

front

road wheels

should

be

properly

balanced.

Therefore,

it

is

necessary to

have all the

wheels

balanceit,

and to

re-balance

a wheel

after

changing

its tyre.

An

out-of-balance

effect

is usually

present in

the

complete

wheel

and tyre due

to:-

(a)

The

valve

and

its

patch

on the

inner tube:

and

3.

4.

Front

Rear

76

TrtB

'R'

TvpB

BBttrrnY.

(b) unavoidable

irregularities

in

the

outer cover,

due to

movement

of

the

material during

vulcanizing.

A coloured

spot

on

the

outer

wall

indicates

its lightest

part, and

the

cover

should

be

fitted so that

this spot

is

at

the

valve

position.

To

correct

such out-of-balance,

four

steel weights

are

spaced

at

intervals

around

the wheel

as necessary.

'

The

method of balancing

the

wheel

is

as

follows:-

(i)

Remove the

wheel.

Fig.

34.-WHEEL

BALANCE

WEIGHTS.

1.

Balance

weight.

2.

Balance

weight

adiustment

holes.

3.

Wheel

securing

nuts.

4.

Wheel

disc

rubber.

1

2.
3

4.

Fie.

35.-SECTION

OF

Well base

rim.
Wheel disc.
Wheel

securing

nut

Balance

weight

FRONT

HUB

AND

WHEEI.

5.

Brake

adiuster.

6.

Hvdraulic

pipe.

7. Bleeder

connection'

SrnrnrNc,

Snocr

Deuprns,

RoAo SnntNGs, Wnnnrs

exo

Tynrs.

77

(ii) If a hub on a bench

is not available, make

sure

that the

front hub on the car is

quite

free to

rotate and not restricted

by

too close

adjustment of

the

brakes.

(iii)

Remove

all balance weights, bolts

and nuts.

(iv)

Reverse

the

bolts

in

the wheel, this

will

allow

the operation

of balancing to be

performed

more

easily, as the balance

weights may then

be fitted externally.

(")

Refit the wheel to the

hub. Allow to swing

and

note

the

tight

point.

Put

one

weight here.

Allow the wheel

to

swing

again.

If the wheel

is in balance, space

the other 3 weights

evenly round the wheel.

("i) If the light

point

is unchanged

in

position, add a second

weight,

using one

of

the

adjacent

holes. If

this corrects

the balance,

add

the other z

weights

opposite

each other.

1.
2

Fig.

35.-SECTION

OF

Well

base rim.

Wheel

disc.

REAR HUB

AND WHEEL.

3. Wheel securing nut.

4. Balance weight.

?8

THE

'R'

Tvpr BBNrtBv.

(vii) If

z

weights together are too much,

try

moving

them away

from

each other.

Go

one

hole

at a time and move each

weight alternately.

When

balance

has been achieved

add

the z weights opposite each other.

(viii) If

z

weights together are insufficient,

add a

third,

using

an adjacent

hole.

If this balances

the wheel,

remove the

centre

weight and refit it 4 holes to one side. Fit

the

4th

weight

4

holes to the

other side.

(i") If

3

weights are insufficient,

add the

4th,

and if this is too

much, start separating

the outer

z

weights as in (vi) above.

(")

Remove

the

wheel and reverse the

bolts so as to return

the

balance

weights

to their correct

position, on the inside of

the wheel.

("i) Refit

the wheel and

the

wheel

disc

assembly.

The

correct

tension

on

the disc is attained by

giving

the

nut one com-

plete

turn, with

the

special

spanner

provided, after

the disc

has

been felt

to

be

in contact with the

rubber stops on

the

wheel centre.

EncrNB

CoorrNc SysrBna.

79

CHAPTBR

IX

Engine

Cooling System

Coolant-Coolant

Pump

and,

Fan-Fan

Belt Adjwstment-Oaerheating

-Engine

Thermostat-Radiator

Mounting-Frost

and Anti-freeze

Mixtures-Car

Heater.

Goolant.

The cooling system

is filled

with a

zS

per

cent. mixture

of inhibited

ethylene

glycol

and water

before

the

chassis leaves

the

factory,

and it

is strongly

recommended

that

this,

or a similar

anti-freeze

mixture,

is

used

all

the

year

round,

both summer

and winter.

The

purpose

of

this is not

only to provide protection

against

frost

during the

cold

weather,

but also to prevent

any corrosion of

the

coolant

passages

and subsequent

deterioration

in

the

standard

of

cooling,

If

there is

any abnormal loss

of coolant,

the cause should

be

ascer-

tained and rectified,

and

the system topped

up with

the correct

anti-freeze

mixture

to

maintain

the

level

to

the bottom

edge

of

the

filling

orifice.

If

either of

the

recommended

compounds (see page

Bz) are

not

available,

plain,

preferably

soft, water

may

be

used

when there is

no

danger of

frost.

The radiator filler

is

located

under the

left-hand

side of

the bonnet.

A

warning notice is

embossed on

the

cap

to

the

effect

that it

must

not

be

removed

when the engine

is

running.

Hot

coolant

is likely

to

be

forced out in

such

circumstances.

A drain

tap

is

situated on

the

pipe connecting

the pump

with

the

bottom

of

the

radiator.

It is in the

"off"'position

when

the handle

is

pointing

downwards.

On

no account

must

any

strong

alhaline

compound

be wsed

to clean

out

the

coolant system.

Seaeral

swch

compounds

are aaailable,

but

their

use

must be

carefully

auoided, owing

to theiact that they

haae a

d.etrimental

chcmical,

action on

al,uminium.

It

is very

important

that a glycerine.base

compound

should

not be

mixed

with

a

glycol

base

compound,.

TnB

'R'

TypB BBNrrBy.

Coolant Pump

and Fan.

The centrifugal

coolant

circulating pump

is

mounted

in

tandem

*i!h

the

fan,

on

the front part

of

the cylinder block,

and is

driven

by

a

"V"

belt,

which

also

drives

the dynamo, from

the

front

end of

ihe

crankshaft.

It

is improbable

that

any

leakage

or any other

trouble will

be

experienced

over long periods

of

running,

and no attention

should

be

necessary between

general

overhauls

of the

chassis.

If,

for any

cause,

the engine

has

to

be

run with

the

fan

removed,

it is

essential

that

the

fan

retaining

set-screws,

with

suitable

distance-

pieces

to allow

for

the thickness

of

the fan, are refitted

in position.

Fan Belt Adjustment.

Normally

the belt

should

not require

adjustment.

An

adjustment

is

pro_vrlfe{.

however,

and

is

effected

by releasing

the three

nuts

(9,

4

and 5,,

Fig.

37), and

moving

the

dynamo

outrvards

on

the

special

slotted link.

The tension

should

be

such

that

the fan

belt

can

be

moved

transversely,

with the fingers,

at

a

point

equidistant

from

the

crank-

shaft pulley

and

the

fan

pulley

through

a

total

distance

of one inch.

If

it

should

be necessary

to remove

the

belt

for

any

reason, it

must

not

be

strained

over the pulley.

The three nuts

(8,4

and 5),

should

be

released

and

the

dynamo moved

upwards

to

the

full

extent

of

the

slot,

when

it

will be

found

that

the belt

can be

easily

replaced

without

straining.

The

fan

must

not be

forcibly

turned,

by lmnd

as

this will cause

bending

of

the blades

and

may

result

in

a damaged radiator.

overheating

may

be

due

to one

or

more of

the

following

causes:-

(a)

The

thermostat

may

have

failed.

(b)

The fan

belt

may

need

adjustment,

Jig.

37.-THE FAN

BELT ADJUSTMENT.

1.

Dynamo.

2.

Slotted

link.

3, 4,

5. Securing nuts.

6, Thermostat.

Overheating.

ExcrNB CoorrNc

Svsrnu.

8r

(c) There

may

be a shortage

of coolant

in the

system.

(d) Detonation

and

poor

grade

of

fuel.

(.) Radiator

matrix

blocked

with flies

or dirt,

etc.

Engino

Thermostat.

The

thermostat

which

controls

the

flow through

the

radiator

to

suit

the

engine

cooling

requirements

is

contained

within

a casing

(6,

Fig.

37).

It

is

arranged

to

maintain

a minimum

coolant temperature

of

approximately

78"C.

Reference

to

the

instrument-board

thermometer

will

indicate

that

the thermostat

is operating

correctly

and that

there

is no shortage

of coolant.

An

unusually

and

consistently

low

temperature,

after the engine

has

been

well

warmed

up,

indicates

failure

of the thermostat.

A

by*pass

pipe acts to short

circuit

the

radiator when the

thermoslal

valve

is

closed

or only

partly open. This

arrangement

ensures

a

quick supply

of

heat to

the

induction

pipes a-fter

sta_rting

from

cold

as

well

as a

rapid warming

up of the engine

coolant

jacket.

Radiator

Mounting.

The

radiator

comprises

two

main

units, namely, the

outer shell

and

the

matrix

itself, the

complete

assembly

being

mounted

on a single

central

rubber

support.

The

shell

is

diagonally

braced

and

is bolted

to the

wings

and

valance

plates.

The

radiator

matrix

is

secured

in

the

shell

at

tfiree

points, which

are arranged

to

proVide freedom

for

expansion

under

heat.

The

object

of

this special

construction

is to avoid sidewaVf move-

ment

of

the

radiator

assembly

due to

road shocks,

and to

isolate

the

matrix

from such

shocks.

No

lubrication

or

attention

is necessary

in

connection

with

the

mounting.

Frost

and

Anti-Freeze

Mixtures.

As

long

as

the original coolant

is

maintained

in

the

system,

no

precautions

need

be taken

against frost.

If, for

any

reason,

the original

coolant has

been replaced with

water,

then the

system

must

be drained

if

the

car

is

to

be

left

exposed

to

temperatures

below

3zo

F

8z

TnB

'R'

Tvpe

BBurrrY.

Fig.

38.-CYLINDER

JACKET

DRAIN TAP.

1,

Drain tap.

Draining

is accomplished

by

opening

three

drain

taps,

one

situated

on

the

pump

inlet

pipe,

one

on the

right-hand

side

of

the

cylinder

block,

(1

,

Fig.

38),

a1d

one

on

the

car

heater

return

pipe.

The

filler

cap

must

also be

released

a

few

turns.

Also, before

attemPting

to

turn

the

crankshaft

for starting

after

exposure

to

frost,

hot

water

showld,

be

poured,

ouer

the

coolant

fwmf

to

thaw any

particles.

of

ice whiCh

may

be

present

in

the

casing,

and which

would

probably damage

the

impeller.

A

suitable

anti-freeze

mixture

is

made

by

mixing soft

water

with

either

Inhibited

Ethylene

Glycol

or

"Bluecol",

in

pro-

porfions

dependent

on the degree

of

frost

likely to

be encountered.

The following table

gives

an

approximate

indication

of the

amount

of frost

protection

ensured by different

strengths

of

mixture.

Freezing

point

Degrees of frost

r,z"

F.

zo"

F.

2"

F.

300

F.

ro

pts.

ro

pts.

-30

F.

35"

F.

r.

Inhibited

z.

"Bluecol"

Ethvlene Glvcol

...

6f

pts.

6f

pts.

rr

pts.

rr

pts.

When

changing from

water

to anti-freeze,

the

radiator

system

must

be drained. New

anti-freeze oI

the

required

amount

should

be

mixed

with

an equal quantity

of soft water

before

being

poured

into the

radiator, the radiator being

finally topped

up

with

soft water.

The

engine should then

be run until

normal

operating

temperature

is reached,

to ensure uniform distribution

of

the

anti-freeze

throughout

the system.

The

rubber connections must

be

carefully

examined

and

replaced

if trnsound,

as any

leakage

will

necessitate

replenishment

with

anti-

I

reez-e mixture.

\il

hen using

an anti-f reeze

mixture

as

described,

a similar

mixture

should

be used for topping-up

purposes

Gan Heaten.

A

hot

water

heater

is

warm

air being

circulated

the

heater.

fitted under

the

front

Passenger's

bv

an electric

fan which

is integral

seat,

with

Excrne

CoorrNc

Sysrnu.

B3

Hot

coolant

is circulated

through

the

heater from

the engine cooling

system.

The

coolant

is

taken

from

the cylinder block

through the

isolating

tap,

trig. 39, to a

manually

operated

valve, 3, Fig. 2,

and

then

to

the

heater,

the

return

being made

to the coolant pump.

The

switch

mounted on

the

variable

control

Fig.39.-CAR HEATER

ISOLATING TAP.

for

the

heater

fan

incorporates

a

instrument

board, as shown

in Fig.

of.

the

interior

temperature.

rheostat,

and

is

1,

thus

giving

a

Page 84

DIAGRAM

ELECTRICAL

WIRING

THe ErncrRrcAl

Sysrru.

85

CHAPTER

X

The

Electrical

System

G

ener

al-Dynamo-F

us e B

o

x-O wtpwt Regul,ator

and

C wt-Oi

ut-switch-

b o x- A mm et er

-B

att er

y

-F

ir

st C h ar g

e-T o

p

p

i ng-

U

p

-

S p e cif.c

G:r au ity

of

Electrol,yte-charging-charging-

BatteVy

fVoni

owisid,i

so%rce-

M ai nt en

qn

c e-1.

gniti

o

n- I

gniti

o n- C o iI-

I

gniti o n T

imi ng-F

ir i ng o r

d er

of

Cylinders-Sparking

Pl,ugs-starter

Motor-starter

Motor

Suitch-

Micro-Switch-Use

of Starter

Motor-Electric

Fuel,

Pumps

and Gauge-

Electric Horns-De-misting

Eqwipment-Electrical

Fiwk

Locati1n-

Recornmended

L!*!

BwIbs-H

eadlamps-Replacing

a H eadlamp

Butb-

Aligning_the leadlamps-The

side- Lamps-Radio-To

sei up

the

Tuning

Push Bwttons.

General.

The equipment

comprises_a

dynamo,

fuse

box,

automatic

output

regulator

a_nd

cut-out,

switchbox,

ammeter,

a

rz-volt,

approximately

ss-amperq-h9ur

battery, a

starter

motor

with

relay-opeiated

switch,

two

electric

horns

with push-button

switch

at head

of

steering

column,

!ead,

side,

rear

and interior

lights,

windscreen

wiper,

trlfficators,

de-froster,

de-mister,

car heater,

radio,

electric

fuel pumps

and

gauge,

and battery

ignition,

consisting

of coil

with

com-bined

low-t6nsiin

contact

breaker

and

high-tension

distributor,

and

the

necessary

wiring.

Incorporated

in

the

distributor is a governor,

which

effects

automatic

control

of

the ignition

timing.

The wiring

diagram

(Fig.

40),

shows

the units

urith

their

electrical

connectiorp,

the various

wires being

indicated

in

colours

to

correspond

with

those

of

their actual

coverings.

The

electrical

system is-earthe4

or.

the

positive

side

of the

battery

to the

chassis

frame,

and

all

switching is

done

in

the negative

leads.

-

Before

doing any

work

on a chassis

which is

likely

to involve

the

electrical

system, it is

advisable

to remove

the

chassis

fiame

connection

f.]roq

the p-ositive

battery

terminal,

and

so

render

the

whole

system

9ead,

but

do not

disconnect

whilst

any

charge

or

discharge

current

is passing.

86

THn

'R'

TvpB

BBNTTBY.

Dynamo.

The

dynamo,

shown

in Fig.

41 , is driven

by

the

same

belt

which

also drives

the

water

pump and

fan.

It

is

of the

shunt-wound

type,

the excitation

of the

field

being

automatically

regulated,

in

order

to

adjust

the

charge

rate to

suit the dynamo

speed,

the

state of

charge

of the

battery

and the

lighting

load.

There

are three

external

terminal

connections,

two

large and

one

small,

one

large

terminal being

the

"armature" connection,

the other

one being

eatthed

to the

chassis frame.

The

smaller

terminal

is the

"field"

connection.

The

armature

lead

from the large

terminal

is taken

to the

output

regulator

and

connected to

the terminal

marked

"D",

and

similarly

the

field

connection

is to the

terminal

marked

"F"

in

the

fuse box.

1.

Dynamo.

Fie.41.-THE

DYNAMO.

3.

Slotted

Link.

2. Cover-Brush

Gear,

4, 5, 6 and

7, Securing

Nuts.

Every

2o,ooo

miles,

as directed

on

page

33,

take

out

the securing

screws

and remove

the

cover. This will

expose

the

commutator

and

brushes,

which

should

be

inspected. Deposits

of

brush

dust,

moisture

and

oil

should

be

removed,

and

note taken

of any appreciable

wear

of the

brushes.

Cleanliness

of the

commutator and

freedom of the dynamo

brushes

in

their

holders

are

the most important

points

in

the

maintenance

of

the

dynamo.

Premature

failure or excessive

wear,

however,

indicates Some

definite

fault

in the

machine,

which

should

be

returned for

correction.

fn

normal

circumstances

the brushes

should

need replacing

only after

considerable

running;

in

the event,

however,

of

a new set

of

brushes

being

required,

it is

recommended

that

this

work should

be done by

THn ETBCTRTcAL

SysrBnr. 87

Messrs.

Bentley Motors

(t93t)

Ltd., or one of their

"Special

Retailers".

Emphasis

is

laid

on

this

point,

as cases have arisen of faulty

operation

of the dynamo,

due to

inexpert

fitting

of brushes.

When

it

is necessary

to disconnect

the wires to the

dynamo, care

must be

taken

to ensure their

correct

replacement.

Fuse Box.

The

large

fuse

box

(2, Fig. 42)

carries

the

circuit

{uses. Each

circuit

fuse

is

one strand of

No.

3z

S.W.G. tinned copper

wire.

The small

fuse box

(1

)

carries

the main

fuse; this is

three

strands

of No.

Sz

S.W.G. tinned copper

wire.

Spare

fuse

wire

of

this

gauge

is

provided

in

a special holder within

the

large fuse

box.

Special care must

their holders,

and that

Output Regulator

and Gut-Out.

The output

regulator

and cut-out

are mounted on the front

of the

dashboard,

and are shown

(5,

Fig.

a2).

The

output

regulator

operates

to

control

the

dynamo

output

by

varying

the field

excitation

in

accordance with the load on

the

battery

and

its

state of

charge.

The

operation

of

the regulator

depends upon

the fact

that the

voltage

of a battery

varies between certain

fixed limits

according

to

the

state of charge

of the battery,

the voltage being,

of

course,

a

maximum

when the battery is

fully charged,

and a

minimum

when the

battery is fully

discharged.

The regulator

is combined

structurally

with

the cut-out.

The

regulator

and cut-out

are,

however,

electrically separate, employing

separate

armatures,

though

they possess field

systems which are

common

over

a portion

of

the

magnetic

path.

The cut-out

is operated

when

the

dynamo

speed rises high

enough

for

the

dynamo

to

charge

the battery by means of its

shunt

coil

connected

across

the main

terminals

of

the

dynamo. This closes

the cut-out

contacts

and so connects

the

dynamo with the battery,

via

thp regulator

and ammeter,

as

shown in

the wiring

diagram

Fig.

ao).

The series coil

is so connected

that, when carrying

the

charging

current,

it

assists

the

shunt coil

in holding

the

contacts firmly

together.

When

the

dynamo

slows

down, and

its

voltage

falls

below

that of

the

battery,

the current

reverses

through

the

seri"es coil,

and the effect

of

the shunt

wrnding

becomes neutralised,

which results

in

the

contacts

falling

apart.

be taken that

all

fuses

are

gripped

firmly

in

the contacts

are clean and

bright.

B8

Tsn

'R'

TypB BBxrunv.

Fis, 42.-F!JSE

BOX, OUTPUT

REGULATOR

AND

CUT'OUT.

Main

fuse

box.

3. Cover,

fuse

box.

5. Output

regulator

and

cut-out.

Circuit fuse box.

4.

Joint

box.

6.

Spare

fuse

wire holder.

The output

regulator

and

cut-out

requires

no

attention;

it is a

sealed

unit,

and no

adjustment

of any kind

must

be attempted.

If any

defects

in operation

should

develop, as

described

under

"Electrical

Fault

Localion"

(p"g.

98),

which are traceable

to

the

regulator,

it

must

be

detached

bodily and

returned, uith the

seel

unbroken,

to

Messrs.

Bentley Motors

(tggt) Ltd. or one of their

"Special

Retailers",

for

correction.

Tnn

ErrcrRrcAl

Sysrru.

89

Switchbox,

Mounted on the instrument panel,

this

unit

includes:-

(a)

Master

switch and lamp

switch

combined.

(b)

Ignition

switch.

(c)

Push-button switch for

the starter

motor.

(d)

A

lock which

can be locked

and the key

withdrawn

either:-

r.

When the

master

switch is in

the

rlOfftt

position;

or,

z.

When

the

master

switch is in

the

r(P.L."

(parking

lights)

position.

No

attempt

must be

made

to lock

the

switch in

other

positions.

With

the

master

switch in

the

rrOfitt

position,

all

accessories

and

liglrting circuits,

with the

exception

of

the

roof

lamp,

are rendered

inoperative.

l\{ovement

of this

master

switch

to

the

rrOnt,

position

renders these accessories

available.

The

various

combinations

controlled

are

clearlv

indicated,

as

follows:-

Ofr.-All

circuits

off

except

for

roof

lamp.

On.-Accessories

available.

S. and T,-Side

and tail

lamps

on and

accessories available"

H.,

S. and

T.-Head,

side and

tail lamps on

and accessories

available.

P,L.-((Parl<ing

Lights", side,

tail and roof lamps

on. (No reading

is

shown on

the

ammeter

and all

other accessories are

"off

".)

A

separate switch is provided

for

the

ignition,

marked

trOnt'

and

t'Off".

Normally,

this switch can be

left

in

the

ttOnt'

position,

and

the

switching to

start the engine

can be

carried out on the

master

switch.

No independent

charge

position

is

provided

owing

to the

presence

of

the output regulator.

Whenever the

master

switch

is

on, connections

are

made

which

cause

the dynamo

to charge

the

battery

through

the

regulator,

as

previously

described.

Operation

of

the

push-button

switch for the starter

motor

completes

a

relay

circuit,

which

in

turn

causes the main

starter switch to

close.

Amm'eter.

The ammeter

is

an

instrument

with

a central zero

and

3o-ampere

range,

a

needle deflection indicating

Charge

or Discharge.

As

already explained

]rnder

"Outpu!

Iegulator",

th9 charge

rate

varies

in accordance

with the

state

of the battery.

Consequently,

no

alarm

need

be felt

if

the

charge

indicated

on the ammeter

is quite

small,

especially

after a considerable

period

of running with no

extra

consuming

apparatus,

such

as

lamps,

in

use.

9o

TsB

'R'

TypB Bnrqrrpv.

This

will probably

indicate

that the battery is well charged.

Under

these circumstances,

switching

on

the

headlamps may

cause

a

discharge reading

to

be

shown,

but this

will

only occur

ior

a

short

time,

as

the

dynamo will

quickly respond

to the slightest

drop in

battery

voltage,

due

to the

discharge, and re-adjust

the output

accordingly.

An

unnoticed

reversal

of

the ammeter connections

causes

the

charge

and

discharge indications

to be

reversed.

Battery.

The battery recommended

and specified for

this car, is

as follows:-

Battery Maker's

Type Designation.

Normal

Charging

Current.

P. & R.

Dagenite.

Exide.

6

H,ZP7-S

6 MXP9-R

5

amperes.

The full

title should

be

given

when

ordering

a replacement

battery

or spare

parts.

First

Charge.

If the battery.

i,s

received

in

a

dry

condition,

it

will

be

necessary

to

fill

the cells

with

acid

solution

of

the

correct

specific

gravity

and

charge

the battery,

before

it

is put

into

use.

In such

cases,

it is

strongly

recommended

that

the

necessary

charging

should

be undertaken

by

. properly

equipped

service station,

as

urilesi

the

initial

charge

is correct

the

battbry

will

never give

satisfactory

servtce.

Topping-Up.

.

In

the majority

of

cases,

however,

the

battery

will have

already

been

charged

and

the cells

filled

with

acid

solution.

Under normal

op.erating

conditions

the level

of

the

solution

will

gradually

fall in

each

cell, mainly

owing

to- evaporation

losses.

A regular

inspection

should

be

made,

as

directed

on

page

3o,

to

see

thai the

level of

the

acid.

solution

has not

fallen

to

such

an

extent

that the

tops of

the separators

and plates

are

exposed.

I1 this case,

the battery

should

be

"topped-up",

by removing

the

vent'Pl"g.in

the centre

of

each

cetl

lid

^"ita

utiaing"distilled

water

to each cell;

until

the level

of

the

solution is

approximately

f-"

above

the

tops of

the

separators.

It is

difficult.to-lay

down

a

hard

and fast

rule

as

to

how frequently

"topping-up"

qilt

.be.required,

because

this

varies

so

much,

according

to the

use

to which

the car

is

put,

and also

the temperature

in

whic6

it operates.

It must

be

remembered

that

"topiing-up"

will

be

necessary more

frequently

in

hot

weather

than in Cold.

- -

TnB

ErBcrRrcAL

SYsrru.

Normally

it

should never

be

necessary

to add sulphuric

acid

to the

cells,

unless

it is

definitely

known

that

some

of

the

acid has

been

lost

owing

to

slopping or spilling.

The addition

of

acid

to

the battery

should

only

be done

by an experienced

battery

man,

who

at the

same

time

will

carry

out any adjustments to

the acid

gravity.

Specific

Gravity of

Electrolyte.

Various

acid specific

gravity

figures are

given

for

reference in

the

following table,

and

they

apply to both makes of

batteries.

Acid

gravity

figures are

taken by

means

of

an hydrometer.

Specific

Gravity

of

Sulphuric Acid

Solution.

(Corrected

to

7o'

F.).

9r

Filling

in

for

First

Charge.

F ully

Charged.

Climate.

Temperate

Tropical

(i.".

where the

temperature is frequently
9oo

F. or over).

6 HZP1-S

6 MXP9R

r.z6o

r.r90

t.z8o

(r.z7o-r.285\

T.2TO

(t.zoo-r.zr5)

Charg ing.

The

output of the dynamo

on

the

car is controlled

so as to vary

with

the state

of charge

of

the

battery.

Overcharging

the

battery is

thus

automatically

avoided. The dynamo will, under

ordinary running

conditions,

provide

enough

current to ensure

re-charging of

the

battery,

but

in special cases,

e.9.,

when the

car is frequently standing with the

lights

on

and daylight

running

is of short

duration,

it

may

be

necessary

to take

the

battery off the car

from

time to time

for a

bench

re-charge.

This re-charge

can be done

by any well-equipped service

station.

-

Ghanging Battery

from an

outside

source,

It is possible

to

charge the

battery from a trickle

charger

whilst

in position on

the

car,

making

use of a

flexible lead and the special

two-pin

plug supplied,

which

fits

the

charging

plug

socket on the facia

board

arranged

just

above the

steering column.

Be certain that the direction

of

current

is correct, the socket

holes

are marked * and

respectively, and,

in

addition,

are

made

of

different

sizes

in

order to

clearly

distinguish

them.

TnB

'R'

TvpB BrNrrny.

Maintenanco.

The

battery must be

well

secured in its box so

that

it

cannot

move.

The cable terminals should be well coated

with lanolin

or

pure

vaseline (not

grease),

before putting

the battery

into

service.

The top of the battery

should always

be kept

clean,

and as

far

as

possible,

dry; attention

should be

given immediately to the

least sign

of

corrosion occurring on

the terminals.

Keep the terminals and

connectors

well covered

with

lanolin or

pure

vaseline,

all

contact surfaces clean and firmly screwed

op, but do

not

use abrasives for

cleaning.

To

remove corrosion,

use a

solution

of

ammonium

carbonate,

applying with a

rag.

Do

not inspect

the battery with the

aid of

a naked

light, and on

no account disconnect

anv of

the

batterv terminals

or connections

when a charge

or dischar["

"urr.nt

is

passing.

The battery

must

never

be allowed to

remain

in

a discharged

condition. A battery not in

service should

be kept

in condition by

fully

charging

it and

then

giving

it a freshening

charge at

least once

every two months.

It

should

be given a thorough

charge

before being

put back into

service.

Care should be taken

to avoid an

inadvertent

discharge

of the

battery.

Such a discharge

may

occur

if

there

is

an earth

in the

wiring

system,

instruments

or

fittings,

or

if

the

ignition

switch

be left on

in

error, and the engine

happens

to come to

rest

with the

low-tension

contacts

in

engagement.

Provision is

made

for

the latter

contingency

by

the

red

warning

lamp,

which rvill

remain

illuminated

until the

ignition

switch is

turned off.

It should be

made

a practice,

when leaving

the

car,

always to

observe

that

the warning

lamp

is not illuminated,

and no switches

are

left on, and

that no

discharge

is

shown

on

the ammeter.

lgnition.

The

battery

ignition

contact breaker and

distributor

are shown

in

Fig.43, an internal

view

of

the contact

breaker

being

given

in

Fig.

44.

A

condenser (4,

Fig.

aB)

is connected

across

the

contact

points.

In setting the points,

the

gap

opening

should

be .or9"

(.+8g

m/m.)

to

.o2r'(.SSS

m/m.), adjustment

being effected

byloosening

the

locking

screws

(3

and 4,

Fig.

44) and turning

the

adjusting

screws

(5

and 6)

to

obtain the

correct gaps,

measured

with

a

feeler

gauge.

Make

sure

that the locking

screws

are

correctly tightened

aftef

adjustment.

The

screws

(7

and

8)

must

not

be disturbed,

as this

would

upset

the

synchronism

of

the two

contact

breaker

arrns.

Every

5,ooo

miles, as

directed

on

page

3r,

the

rocker

arm

pirrgt

pins

(9

and 1O)

should

be

lubricated

with one

or

two drops

of

'oil

"4";

at

the

same time

apply

one

or two

drops

of

oil

"8" to

the

cam

lubri-

cator

pad.

Also remove

the

rotor

and

apply

a

few

drops

of

oil

"A"

to

the

felt

wick (12),

to lubricate

the automatic

timing conhol.

TnB

ErBcrRrcAL

SvsrEM.

93

The

lubricator

(3,

Fig.

43;

should be

given a turn

every rrooo miles, and

when

empty,

refilled with

the

correct

grease,

as specified

on

page

28.
The

rotor

incorporates a

small

carbon

resistance

sup-

pressor,

to

comply with

reg-

ulations

governing

telcvision

interference.

The

high-tension

distrib-

utor

requires no

attention

beyond an occasional

rviping

of

the

interior and

exterior

with

a clean, dry

rag.

lgnition Coil.

The

high-tension

ignition

coil

is mounted

on

the,front

of

the

engine,

as

illustrated

in

Fig.

45.

Connected

to

the

terminal

marked S.W.

(switch

wire)

is a

r mfd. condenser

to

reduce

electrical

interference

to

the

radio from the

ignition

system.

Care

must be taken

that

in

the

event

of a replace-

ment

coil being

fitted, that

the

condenser

is

correctly

connected

to the terminal

marked S.W.

and

not

to the output (C.8.)

terminal

of

the

coil.

The

outside

of

the

coil

casing should

be

kept clean;

misfiring is

occasionally caused

by an accumulation

of

dirt

around the terminals.

lgnition Timing.

If the

ignition

timing has been

deranged, it

can be

reset by reference

to

the

markings

on

the engine flywheel.

To

carry out

this

operation,

the crankshaft should

be rotated until

the

mark

'rlGN.

TDC.''

on

the flywheel registers urith the

small

pointer

_attached

to the

lower

bell-housing cover,

'when

No. r

piston

is

at

thb top

of its

firing stroke.

The

car

should be run up on a

ramp

or over

a

pit.

Examination

of

the lower

bell-housing cover (3,

Fig. 22)

will show the

small inspection

hole

on the side.

The

preferable method

is

to note

the

position

of the

pointer

and

then

to remove the cover.

Operate

the starter

motor

to

approximately

line up

the

flywheel marking;

replace

the cover for a temporary

check.

Remove

the cov_er an{

prise

the flywheel

round into correct

position,

then permanently

replace

the cover.

Fts.

43.-IONTACT BREAKER

AND DISTRIBUTOR.

1. Distributor.

4.

Condensen

2.

Contact breaker

5. Spare condenser

3. Lubricator.

94

Tue

'R'

TvpB BBurrBv.

Another

method is

to

use the

starting

handle to turn

the en-

gine,

which

obviates the

need for

removing the

bell-housing

cover. It

must be

remembered

that

the

starting

handle

operates

through the

friction

damped

spring

drive

unit,

and

there-

fore

allowance

must

be

made

for

the wind-up

of

the

spring drive unit.

If

it is

decided

to use

this

method,

the timing

should

be set .3oo"

late

of the

lGN.

TDC.

Fie. 44.-INTERIOR

OF

CONTACT

BREAKER.

1 and

2.

Rocker

Arms.

7

and 8.

Synchronising Adjustment.

3 and 4. Locking

Screws.

9 and 10.

Pivot Pins.

5

and 6.

Adjusting

Screws.

11. Cam.

12. Felt

Wick.

mark

on

the

periphery

of

the

flywheel.

The contact

breaker

should

now

be

adjusted

by

rotating

in

an anti-clockwise

direction,

so

that the

cam is

just

on

the point

of causing

the contact

break

when

revolving in

the normal

direction, while

at

the same

time the high-tension

rotor

is opposite

No.

r

distributor

contact,

the rotor

being

in

the fully retarded

position.

A convenient

method

of

determining

precisely

when

the

break

takes place

is

by

reference

to the

ammeter.

With

the ignition

switched

on,

and someone

watching

the

ammetei,

the engine

shoutd

be rotated

until

the

required

cam

just

breaks

the

contacts,

as indicated

by

the reading

of the ammeter.

The distributor

head

se-

curing screw should

then be

securely

tightened.

Fie.

45.-lGNlTlON ColL.

f. Coil.

2.

Suppressor condenser.

Tnn ErrcrRrcAl Svsrnu.

95

Ignition

timing

variation during

running is entirely controlled

by

the

centrifugal

governor

incorporated in the distributor,

no

hand

control

being

provided.

Firing

Order

of Cylinders.

The

firing order

of

the engine

is,

r,

4,

z, 6,

3,

5,

No.

front

cylinder.

Sparking

Plugs.

Alternative

plugs are

Champion

Type N8, or Lodge

4

m/m.

non-detachable. Every

5,ooo

miles, as

directed

they

should

be removed and

cleaned.

The

width of the

be checked,

and, if necessary,

reset

to .o3o"

(.262

m/m.).

r being

the

Typ" CLN,

on

page

3r,

gaps

should

Starten

Motor.

The

starter

motor

is

shown

in

Fig.46. A small

planetary

reduction

gear

is

arranged

in

a casing behind

the

motor,

the effect

of which

is

to

provide a total reduction gear ratio between motor and

crankshaft

of

16.o :

r.

A

plug

in the

front

cover of the gear

casr-"g..sl*la.

P.

removed.

every

ro,ooo

miles,

as

directed

on

page

32,

and

oil

"B"

injected until

it is

level

with the orifice.

This oil

also

lubricates

the

driving

end

bearing of the armature

shaft.

Fie. 46.-THE STARTER MOTOR.-UNDERNEATH

VIEW

1.

Oiling

plug.