Cub Cadet 5000 User Manual
Service Manual
Domestic Series 5000 Compact Tractor
NOTE: These materials are prepared for use by trained technicians who are experienced in the service and repair of equipment of the
kind described in this publication, and are not intended for use by untrained or inexperienced individuals. Such individuals should seek
the assistance of an authorized service technician or dealer. Read, understand, and follow all directions when working on this equipment. This includes the contents of the Operators Manual, which came with your equipment. No liability can be accepted for any inaccuracies or omission in this publication, although every care has been take to make it as complete and accurate as possible. The right
is reserved to make changes at any time to this document without prior notice and without incurring an obligation to make such
changes to previously published documents. All information contained in this publication is based on product information available at
the time of publication. Photographs and illustrations used in this publication are for reference use only and may not depict actual
model and component parts.
MTD Products Inc. - Product Training and Education Department
FORM NUMBER - 769-01633
12/2004
TABLE OF CONTENTS
CHAPTER 1 - Hydraulics
Standard Hydraulic Systems on the Domestic Series 5000: Orientation ......................................1
Hydrostatic Drive: Basic Operation ...............................................................................................4
External Checks ............................................................................................................................6
Best Practices: Hydraulic Systems ................................................................................................8
Flow and Pressure Tests: Hydrostatic Drive .................................................................................8
Auxiliary Pump ............................................................................................................................12
Steering Pump and Cylinder .......................................................................................................14
Hydraulic Lift Cylinder and Control Valve ....................................................................................18
Loader Valve ...............................................................................................................................22
Component Breakdown: Auxiliary Pump .....................................................................................25
Component Breakdown: Steering Unit ........................................................................................26
CHAPTER 2 - MFD
About This Section: .....................................................................................................................31
Identifying the MFD: ....................................................................................................................31
Domestic Series 5000 MFD ........................................................................................................31
MFD Removal: Preparation .........................................................................................................33
Removal ......................................................................................................................................34
MFD Installation ..........................................................................................................................36
In-Frame Repairs: Drop Axle Service ..........................................................................................37
In Frame Repairs: Drop Axle Cover ............................................................................................38
In-Frame Repairs: Drop-Axle Removal .......................................................................................40
Bench Repairs: Drop Axle and Kingpin Housing Assemblies .....................................................42
Bench Repair: Axles and Differential. ..........................................................................................46
Torque Specifications ..................................................................................................................60
CHAPTER 3 - Rear Axle
Reason for Change: ....................................................................................................................61
Preparation: .................................................................................................................................61
Axle Assembly .............................................................................................................................63
Install the New Axle. ....................................................................................................................64
CHAPTER 4 - Deck Adapter Kit - 190-830-100 65
About This Section: ..................................................................................................................... 65
Preparation and Brackets: ...........................................................................................................65
Lift Shaft and Arms: .....................................................................................................................66
Hanger to Deck Connections ......................................................................................................67
Mating the Deck to the Tractor ....................................................................................................68
CHAPTER 5 - Dash and Steering Pump
About This Section: .....................................................................................................................71
Dash Panel Removal ...................................................................................................................71
The Dash Panel ...........................................................................................................................75
Steering Shaft and Pump: Sauer .................................................................................................77
Steering Shaft and Pump: Ross ..................................................................................................79
I
CHAPTER 6 - Electrical System
Similarities and Differences..........................................................................................................81
Components.................................................................................................................................82
Electric Clutch and Fuel Pump .....................................................................................................90
II
Domestic Series 5000 Hydraulics
Domestic Series 5000 Hydraulics
1. STANDARD HYDRAULIC SYSTEMS ON THE DOMESTIC SERIES 5000: ORIENTATION
NOTE: Subsections 1 and 2 of the Domestic
Series 5000 Hydraulics portion of this manual
provide a basic orientation to the system. Subsection 3 and those that follow it contain specific
test procedures.
NOTE: Hydraulic diagrams are contained in an
appendix to this section.
1.1. The transmission housing acts as a reservoir for
all of the hydraulic systems on the tractor: hydrostatic drive pump, hydrostatic steering system,
lift cylinder, and accessories.
1.2. Fluid: the transmission and hydraulic system are
filled with 5.0 gallons (19.0 L) of Cub Cadet
Hydraulic Drive System Fluid Plus (P/N: 7373120 1Qt., 737-3121 1Gal.).
1.3. Filtration: The hydraulic system filter (P/N:723-
0405) is located on a boss on the front surface of
the transmission housing, adjacent to the midmount, 2000 R.P.M. P.T.O. shaft.
See Figure 1.3.
1.4. The hydrostatic drive filter (P/N: BS-492932S) is
located on the return manifold, atop the transmission. It is accessible through the opening
ben e ath the sea t . See Fi gur e 1. 4 .
Charge pressure tube
BDU-21L-400
Charge pressure tube
from aux. pump
to filter
NOTE: Other than sharing a reservoir, the
hydrostatic drive operates independently of the
rest of the hydraulic system.
from filter to hydrostat
Hydrostatic
drive filter
Figure 1.4
Suction tube
(feeds auxiliary pump)
Figure 1.3
Hydraulic
system filter
1.5. The hydrostatic drive is a Hydrogear model
BDU-21L-400. It relies on the auxiliary pump to
produce charge pressure. The auxiliary pump
draws hydraulic fluid up the suction pipe from
the base of the transmission housing.
See Figure 1.5.
Return tube
Auxiliary
pump
Suction
tube
Figure 1.5
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Domestic Series 5000 Hydraulics
1.6. The steering and lift cylinder are also powered
by the a Sauer-Danfoss SNP 1/2.6 S auxiliary
pump.
1.7. The steering unit, located in the dash pedestal
contains it’s own back-up gerotor charge pump
that will enable steering control when the engine
is not running. See Figure 1.7.
Steering
unit
Figure 1.7
1.10. The control valve directs fluid pressure to a single-acting hydraulic cylinder that lifts the threepoint lift arms.
1.11. The hydraulic fluid flow is as follows:
1.12. Through the pick-up tube from the transmission
sump and filter, to the auxiliary pump.
1.13. Under pressure from the auxiliary pump the fluid
goes to the hydrostatic drive and to the “P” port
on the steering unit. See Figure 1.13.
L port
(pressure to
turn left)
P port
(pressure
from
pump)
T port
(returns fluid
to transmission)
R port
(pressure to
turn right)
E port
(pressure
lift valve)to
1.8. The steering unit directs fluid pressure to one
end of the double-acting differential steering cylinder while allowing it to return from the other
end of the cylinder in order to provide steering
action.
1.9. The lift cylinder is operated by a control valve
under the right rear fender. See Figure 1.9.
Lift control valve
Auxiliary pump
Figure 1.9
Figure 1.13
1.14. The steering unit distributes pressure to the
steering cylinder according to the position of the
steering wheel. Left turn input from the steering
wheel forces fluid out the port labeled “L” and
allows displaced fluid to return through the port
labeled “R”.
NOTE: The power steering unit is first in line,
and has priority over the rest of the system.
1.15. For left turns, the fluid flows from the L port to
the base end of the steering cylinder. This
causes the ram to extend, turning the wheels to
the left.
1.16. The steering cylinder is double-acting: As the
piston is forced down the length of the cylinder
by hydraulic pressure from the L port, fluid on
the ram side of the piston is displaced, returning
through the R port.
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Domestic Series 5000 Hydraulics
1.17. The process is reversed for right turns.
See Figure 1.17.
Pressure from L port
(left turn)
Pressure from R port
(right turn)
Steering cylinder
Figure 1.17
1.18. From the steering system, the fluid may follow
one of two return paths:
1.19. The fluid may pass through the T port, to the
return manifold. See Figure 1.19.
Fluid return from
lift valve
30 PSI
check
valve
Charge
pressure
(30 PSI)
1.22. From the E port, fluid will travel to the lift control
valve. See Figure 1.22.
Pressure from E port
Figure 1.22
1.23. The fluid pressure that comes out of the E port
goes to the outboard port of the lift control valve.
1.24. The lift control valve directs pressure to the single-acting lift cylinder through the elbow on the
bottom of the valve when operator control input
directs it to do so. See Figure 1.24.
Pressure to lift
control valve
Pressure to
lift cylinder
Lift
valve
Fluid return
from T port
Figure 1.19
1.20. From the return manifold, the fluid may be
directed through the hydrostatic drive filter, to
provide charge pressure to the hydrostatic drive.
1.21. Pressure is maintained to the filter and hydrostatic drive by a spring loaded check valve. The
check valve in this application acts to maintain at
least 30 PSI (2.07 Bars) of hydraulic pressure in
the system. Above 30 PSI, it allows fluid to
return to the reservoir (transmission housing).
Return via
return manifold
Direct return
(on down-stroke)
Figure 1.24
1.25. Fluid not required to power the lift cylinder will be
continuously directed back to the transmission
through the lower inboard port (forward facing
elbow) via the return manifold.
3
Domestic Series 5000 Hydraulics
1.26. When the tractor operator moves the control
lever forward to lower the three point hitch, the
lift control valve allows fluid to escape from the
lift cylinder as the cylinder retracts under the
weight of any accessories supported by the
hitch.
1.27. Increased fluid volume beyond normal return
flow rate is generated when the lift arms are lowered. This flow is exhausted through the top
inboard port (rearward facing elbow) back into
the transmission housing via a separate return
tube. See Figure 1.27.
Direct return
from lift valve
2. HYDROSTATIC DRIVE: BASIC OPERATION
2.1. The input shaft to the BDU-21L-400 turns a shaft
that passes completely through the housing of
the hydro., driving an engine speed input shaft in
the transmission.
2.2. The input shaft drives the auxiliary hydraulic
pump and the P.T.O. They are driven at relatively constant engine speed, rather than in relation to ground speed. See Figure 2.2.
Pinion gears driving
auxiliary pump
Traction drive
pinion
PTO clutch
PTO shaft
Figure 1.27
Figure 2.2
2.3. The lower part of the pump contains a fixed displacement axial piston hydraulic motor. The
motor is driven by the output of the variable displacement pump.
2.4. The hydro. control arm (scissors bracket) moves
a swash plate that controls the output of the
pump.
Hydro
control
arm
Set screw
Scissors bracket
4
Figure 2.4
Domestic Series 5000 Hydraulics
S
2.5. : tilting the swash plate in one way causes the
variable displacement pump to drive fluid
through the fixed displacement pump in one
direction. See Figure 2.5.
Variable displacement pump
Input shaft
Fixed displacement
motor
Swash
plate
Pump
block
Motor block
Figure 2.5
NOTE: In figure 2.5, the pistons in the variable
displacement pump are alternately pressed into
the bores, and then released from bores of the
rotating pump block by the tilt of the swash plate.
Swash plate
angle
2.6. Tilting the swash plate the other way causes the
variable displacement pump to drive fluid
through the fixed displacement pump in the
opposite direction. See Figure 2.6.
Fixed displacement
motor
Pistons
Figure 2.6
2.7. When the swash plate is flat, the pump pistons
do not move up and down, no fluid is displaced
and no power is transmitted to the fixed displacement pump.
wash plate
angle
Pistons
• On the right side of the pump block in figure 2.5,
the pistons are down.
• The pistons are extended on the left side of the
pump block. They are forced up by springs contained in the pistons.
• This action causes the pistons to pump fluid in
one direction.
• The further the swash plate is tilted, the greater
the movement of the pistons as the pump block
rotates.
• As the travel of the pistons is increased, the displacement of the pump is increased, and more
fluid is pumped.
• The more fluid is pumped, the faster the fixed
displacement motor is driven.
2.8. The auxiliary pump maintains a supply of pressurized fluid (charge pressure) to the variable
displacement pump to feed and lubricate the
pump.
2.9. The charge check valves direct the flow of pressurized fluid to the ports that feed the pistons of
the variable displacement pump.
• When driving forward, fluid flows into the variable displacement pump through one set of
ports, and out through a second set.
• When driving backwards, the flow is reversed.
• One check valve opens and the other one
closes, depending on the direction of fluid flow.
• If the hydro. is in “neutral”, lubrication is provided
to this spinning (but not pumping) pump and
motor blocks through separate channels in the
housing.
2.10. If the hydrostatic drive is not performing correctly, begin diagnosing with simple things that
can be seen with minimal disassembly.
5
Domestic Series 5000 Hydraulics
3. EXTERNAL CHECKS
3.1. If the transmission creeps, check the neutral
control adjustment. See Figure 3.1.
Neutral return bracket
Figure 3.1
NOTE: Complete neutral control adjustment pro-
cedures can be found in the 2004 Cub Cadet
Technical C.D.
3.2. If the tractor fails to achieve full ground speed,
check the adjustment of the linkages that control
the hydrostatic drive system.
NOTE: A d v e r t i s e d m a x i m u m g r o u n d s p e e d
High range forward:8 MPH (12.9 KPH)
Low range forward: 4 MPH (6.44 KPH)
High range reverse:4 MPH (6.44 KPH)
Low range reverse: 2 MPH (3.22 KPH)
Move shoulder bolt
in slot to establish
neutral
3.4. Confirm that full travel is achieved in the reverse
direction. See Figure 3.4.
Pedal linkage: Reverse
Hydro linkage:
Reverse
Figure 3.4
3.5. If the brake and drive pedals “fight” with each
other, the drive control rod is out of adjustment.
See Figure 3.5.
Pedal linkage:
Neutral
Note:
gap
Note: gap
Brake linkage:
brakes applied
Brake
linkage
3.3. Confirm that full travel is achieved in the forward
direction. See Figure 3.3.
Brake linkage
Pedal linkage Forward
Hydro linkage:
Forward
Note:
gap
Rod pulls hydro linkage
Figure 3.3
Pin locks linkage
Drive control rod
Figure 3.5
NOTE: Isolate the hydrostatic drive unit from the
linkage, and confirm the correct adjustment of
the neutral return before adjusting the linkage.
NOTE: After correct neutral return adjustment is
established, adjust the ferrule on the drive control rod so that it rests lightly against the front
edge of the slot that it fits into when the parking
brake is engaged.
6
Domestic Series 5000 Hydraulics
3.6. If the tractor fails to achieve normal ground
speed, and the hydro pump emits an unusual
amount of noise, check for brake drag:
• Confirm that the neutral return and hydro control
linkages are correctly adjusted.
• With the tractor on a smooth, firm, level surface,
place the gear selector in neutral, release the
parking brake, and attempt to push the tractor.
• If the tractor does not roll with a reasonable
amount of effort, check the brakes for drag.
• The left and right brakes can be checked individually by jacking-up the rear of the tractor and
attempting to rotate the rear wheels. Leave the
transmission in neutral.
• If either or both brakes drag, confirm that the
linkage moves firmly and is properly adjusted.
• If the linkages are properly adjusted, and brake
drag is still present, check the pull-off springs on
the brake calipers.
• Bear in mind that both brake calipers act on a
common cross-shaft within the transmission.
With the rear wheels off the ground differential
action will still occur when the brakes are
applied, unless the differential lock is applied.
• Look for blueing on the brake rotors and freedom of movement when the brakes are
released.
3.8. Check the fluid at sight glass gauge on the back
of the transmission. Check the level, and compare the fluid to a sample of Cub Cadet Hydraulic Drive System Fluid Plus. Top-up or replace
the fluid as necessary. See Figure 3.8.
Sight glass
Suction line feeding
auxiliary pump
3.9. Replace the hydrostatic filter if there is any question of it’s condition.
3.10. Visually inspect the hydraulic system filter and
the suction tube that feeds fluid to the auxiliary
pump from the sump of the transmission. If it is
kinked or crushed, replace it. See Figure 3.10.
Fill plug
Figure 3.8
NOTE: Complete brake adjustment procedures
can be found in the 2004 Cub Cadet Technical
C.D.
3.7. If there is no drive at all, confirm whether the
problem lies in the hydro or elsewhere.
• With the engine running, confirm that the PTO
operates when it is turned-on. This confims that
the input shaft is turning.
• On smooth, firm, level ground, with the engine
turned-off and the parking brake released:
• Place the gear selector in high range and
attempt to push the tractor. It should not roll.
• Place the gear selector in low range and attempt
to push the tractor. It should not roll.
• If the tractor rolls, the problem is gear-related.
• Place the gear selector in neutral and attempt to
push the tractor. It should roll. If it does not, the
problem may be gear or brake related.
Hydraulic filter
Suction tube
to auxiliary
pump
Figure 3.10
NOTE: Drain the transmission fluid before
removing the suction tube.
3.11. Check that the set screw holding the control arm
to the hydro control shaft has not backed-out,
worn, or sheared.
7
Domestic Series 5000 Hydraulics
4. BEST PRACTICES: HYDRAULIC SYSTEMS
NOTE: TESTS All hydraulic tests should be
done with the fluid at normal operating temperature, and the engine at normal operating speed.
In practical terms, normal operating temperature
means that the tractor should be operated (if not
disabled) for about 5 minutes before testing in
normal temperate climates. If the tractor has
been sitting outside for a week during February
in Green Bay, Wisconsin, it is advisable to store
the tractor in a heated shop for 12 hours before
testing. Normal operating speed is 3,000RPM.
NOTE: CLEANLINESS It is very important to
keep dirt out of hydraulic systems.
• Cleaning the areas around any joint to be disconnected, or component to be removed is
advisable.
• Contaminated fluid should be disposed of properly, not re-used.
• Tools and work benches used for work on
hydraulic systems should also be kept clean.
• Catch pans beneath work will ease clean-up.
5. FLOW AND PRESSURE TESTS: HYDROSTATIC DRIVE
NOTE: The fenders have been removed from
the tractor for the sake of photographic clarity.
The test procedure described in this section can
be performed without removing the fenders.
NOTE: It will be necessary to remove the seat.
NOTE: The hydrostatic drive can be removed
from the tractor from beneath without removing
the fenders.
5.1. If the problem is not revealed by any of the
external checks, check the charge pressure.
5.2. Clean the area surrounding the charge pressure
port immediately to the left of the feed tube from
the filter. The plug to the right is not easily
accessible.
5.3. Remove the plug using a 1/4” allen wrench.
5.4. Install a pressure gauge capable of reading 200
PSI (13.80 Bars) in the port that the plug was
removed from. See Figure 5.4.
• CAUTION: High pressure hydraulic leaks can
be dangerous.
• Wear eye protection while performing tests.
• Do not operate any equipment with obvious
damage to parts such as hoses.
• Do not disconnect any fittings that may be under
pressure. Turn-off the engine and operate the
circuit to relieve pressure.
• Remember that anything (front-end loaders,
backhoe buckets, three-point hitches, etc....) that
is supported by hydraulic pressure will be subject to gravitational force when that pressure is
relieved.
NOTE: Sealants
• O-ring fittings require no sealant, though light
lubrication with the fluid used in the system is
sometimes helpful.
• Teflon tape is to be avoided. “Flash” from the
tape can dislodge, blocking valves and damaging pumps.
NOTE: Priming
• When a new hydrostatic drive is installed, turn
the input shaft at low speed until charge pressure builds to avoid immediate failure on initial
start-up.
200 PSI gauge
High
pressure
gauge
Charge pressure port
Figure 5.4
NOTE: Fitting size: 3/8” ORFS
5.5. Confirm that no unsafe conditions will be created
by starting the engine or operating the drive system before performing the test.
5.6. Place the High/Low/Neutral gear selector in neutral, and set the parking brake.
5.7. Start the engine and allow the fluid to warm up
briefly.
8
Domestic Series 5000 Hydraulics
5.8. The charge pressure should read at least 30 PSI
(2.07 Bars) @ 1,200 RPM. See Figure 5.8.
200 PSI gauge
Figure 5.8
5.9. As the RPM is increased to the 3,000 RPM, the
pressure may increase somewhat. If pressure
goes down as engine speed increases, turn-off
the engine and determine the cause.
High pressure gauge
5.11. If the charge pressure is good, but drive has
been lost in one direction only, the corresponding charge check valve may not be working.
• There is a charge check valve located in each
circuit: one for forward, one for reverse.
• These check valves enable the charge pump to
provide charge oil to the side of the circuit that
has the lowest pressure, while sealing-off the
side that has higher pressure.
• The one on the left side maintains pressure in
the forward circuit, the one on the right side
maintains pressure in the reverse circuit.
5.12. The charge check valves can be removed using
a 5/8” wrench. See Figure 5.12.
5.10. After confirming that the supply to the pump is
good, low pressure or a complete lack of pressure at this port indicates:
• The auxiliary pump that is not working.
• Pressure from the auxiliary pump is not reaching
the charge port on the hydrostatic drive. The
steering unit may not be transferring pressure as
designed, or the return manifold check valve
may be failing to maintain 30 PSI (2.07 Bars).
• Pressure is being lost within the hydrostatic
drive, possibly because of a malfunctioning system relief valve.
O-ring seal
Charge check
valve cap
Figure 5.12
NOTE: The one on the right side (reverse) is
easy to reach. The one on the left side (forward)
can not be removed in the tractor. It may be
removed for inspection on the bench.
9
Domestic Series 5000 Hydraulics
5.13. When removed, each charge relief valve comes
out as a cartridge. The light compression spring
provides the check valve function. The heavy
compression spring provides system relief. System relief comes into play in the event of a drive
system overload. See Figure 5.13.
Light compression spring
(check valve function)
Heavy compression
spring (relief function)
5.14. The output of the variable displacement pump is
dependent upon the performance of the check
valves.
5.15. The presence of fluid flow from the auxiliary
pump, via the steering unit can be confirmed by
installing a flow meter in place of the tube
between the filter and the top port on the hydrostatic drive. See Figure 5.15.
Charge check valve cap
Figure 5.13
Flow and pressure test
kit in charge pressure line
between filter and hydrostatic drive unit
5.16. With the engine at a minimum speed of 1,200
RPM, fluid flow of roughly 2 GPM (7.60 LPM)
should register on the meter. See Figure 5.16.
Figure 5.16
NOTE: No hydraulically powered systems
should be in motion during this test. The steering and lift cylinder should be stationary. Confirm that the lift control valve is not in the down
position.
5.17. Conclusion: If flow is present, but there is no
pressure, as determined by the 200 PSI gauge,
then the auxiliary pump is producing flow, the
steering unit is passing that flow along to the
return manifold through the T port, but pressure
is being lost in the return circuit. The most likely
culprit is the return circuit check valve.
5.18. Conclusion: If there is neither flow nor pressure, either there is none reaching the return circuit, or it is being spilled-off through a path that
offers lower resistance.
Figure 5.15
• The lift control valve is the only other possible
outlet from the return circuit. Lift control valve
failure in this mode would be highly unusual. If
the lift control valve operates normally, this issue
can be eliminated from consideration.
• To discern if the auxiliary pump is functioning,
operate other hydraulic systems. If the steering
and the lift cylinder for the three point hitch fail to
operate, it is safe to assume that the auxiliary
pump is not producing pressure.
• The pressure that operates the lift cylinder
comes from one of two possible return paths
from the steering unit (E port). The charge pressure for the hydrostatic drive comes from the
10
other (T port). If there is pressure to the steering
unit, at least one return path will have pressure.
5.19. The return circuit check valve maintains a minimum pressure given sufficient flow. It does not
control the maximum pressure in the system: it
is a check valve, not a relief valve.
See Figure 5.19.
Fluid return from
T port
30 PSI
Check valve
Domestic Series 5000 Hydraulics
5.21. If any mechanical problem is found with the
check valve, it is to be replaced as a unit. Individual service components are not available
through Cub Cadet. See Figure 5.21.
Light
compression
spring
Socket head
plug with
O-ring seal
Fluid return from lift valve
Figure 5.19
5.20. The core of the valve can be removed for
inspection. The nut and set screw are not a
means of adjusting pressure. See Figure 5.20.
Hydrostatic filter
Figure 5.20
Check valve core
Figure 5.21
11
Domestic Series 5000 Hydraulics
6. AUXILIARY PUMP
6.1. The auxiliary pump provides pressure for the
hydrostatic power steering unit, the lift cylinder
attached to the three-point hitch, and any
hydraulic-driven accessories that may be
installed on the tractor.
6.2. Series 5000 tractors come with a single auxiliary
pump mounted to the right side of the transmission. See Figure 6.2.
6.5. The filter and suction tubes are easily reached
for inspection with little or no disassembly.
See Figure 6.5.
Hydraulic filter
Pressure line to P port
on steering unit
Auxiliary pump
Figure 6.2
6.3. If performance of any of the tractors hydraulic
features or attachments is poor, it is necessary
to confirm that sufficient hydraulic power is being
supplied by the pump that drives it.
6.4. Begin with the basics: confirm that the pump
drive and supply are intact before drawing conclusions about the pump itself by making these
preliminary checks:
Suction tube
to auxiliary
pump
Figure 6.5
6.6. The rear fenders must be removed to access the
auxiliary pump itself. Fender removal is
detailed in the 2004 Cub Cadet Technical C.D.
6.7. To test the auxiliary pump, use a flow and pressure gauge set. See Figure 6.7.
To P port
• Check the fluid. If the fluid level is low, or the
fluid is not the correct type, both the hydrostat
and the auxiliary pump will perform poorly.
• Replace the hydraulic filter if there is any question of its condition.
• Confirm that the suction tube that provides fluid
to the auxiliary pump from the sump of the transmission is not crushed or kinked, and that the
connections are free of leaks.
From pump
Figure 6.7
NOTE: Equipment will vary from shop to shop,
but operating principles are similar.
6.8. Disconnect the output line from the top of the
pump using a 3/4” wrench and a 9/16” wrench.
6.9. Install the gauge set in-line between the auxiliary
pump and the steering pump. The pressure
gauge should be near the auxiliary pump, and
the flow meter should be near the steering unit.
12
Domestic Series 5000 Hydraulics
6.10. Set the parking brake, place the gear selector in
neutral, open the flow valve on the gauge set all
the way, and confirm that no unsafe conditions
will be created by starting the tractor engine.
6.11. Start the engine, allow the engine and hydraulic
system to warm-up. See Figure 6.11.
To P port on
steering unit
5 GPM
Valve
open
Figure 6.11
From auxiliary
pump
6.13. Close the flow valve until the pressure gauge
reads 1,500 PSI (103 Bar). Note the flow reading. See Figure 6.13.
1,500 PSI
5 GPM
Valve
partially
closed
Figure 6.13
6.14. As soon as the flow reading is noted, open the
the flow valve completely, relieving pressure
from the system. Turn -off the engine.
6.12. Performance:
• The SKP1/4.3 S auxiliary pump does not contain
a relief valve. It is capable of producing roughly
3,600 PSI (250 bars) at engine speeds beyond
1,200 RPM.
• This is far in excess of the needs of the rest of
the system, which is designed to operate at
1,500 PSI (103 Bars).
• For our purposes, it is not necessary to test the
pump to its full capacity, only to establish that it
produces enough flow and pressure to operate
the hydrostatic steering and hydraulic lift cylinder.
• The auxiliary pump was observed to move about
4.6 GPM (15 LPM) at an engine speed of 3,000
RPM, with no load applied.
• Flow will vary with engine speed, but pressure
tests can be done at lower engine speeds:
1,200-1,500 RPM.
• Set the throttle to maintain an engine speed in
this range, and note the reading on the flow
meter.
6.15. The flow readings noted at zero pressure and
1,500 PSI (103 Bars) should not vary significantly. Flow is more related to engine RPM than
to pressure.
13
Domestic Series 5000 Hydraulics
7. STEERING PUMP AND CYLINDER
NOTE: It is normal for the spokes of the steering
wheel on an open-center hydrostatic power
steering system to change orientation with use.
There is no mechanical connection between the
steering wheel and the front wheels.
7.1. Identification: The Sauer OSPM 63 PB unit has
a round body. The ports are on the bottom of
the steering unit connecting to the hydraulic lines
with male straight thread O-ring seal fittings. See Figure 7.1.
7.5. The following set of symptoms, causes, and
solutions has been adapted from a list compiled
by Sauer-Danfoss to aid in the diagnosis of
hydrostatic steering issues. Internal steering
unit problems are described to aid technicians in
distinguishing internal steering unit problems
from problems that lie elsewhere in the system.
Internal problems dictate replacement of the
steering unit.
• High Effort Required to Turn Steering Wheel:
Cause 1: The auxiliary pump is not supplying suffi-
cient fluid to the steering unit. Confirm by testing auxiliary pump out-put.
Solution 1: Correct the problem with the auxiliary
pump.
Cause 2: The priority spool within the steering unit is
not moving, causing fluid to be directed to other parts
of the system when the steering system needs it.
Solution 2: Internal problem; priority spool.
Cause 3: The relief valve in the steering unit is stuck
open.
Figure 7.1
7.2. The ports are arranged as follows:
• P Pressure from the auxiliary pump.
• T Tank return of fluid pressure and volume not
required by the steering system.
• E Equipment power for accessories.
• R Right turn, pressure out when turning right.
• L Left turn, pressure out when turning left.
7.3. R&R: instructions for removal and replacement
of the steering units can be found in the DASH
PANEL AND STEERING PUMP section of this
manual.
7.4. If there is a warrantable problem with the power
steering unit, it is to be replaced as a complete
unit. Cub Cadet does not stock any internal
components for the steering units.
Solution 3: Internal problem; relief valve.
• “Motoring” Steering Wheel: rotates on its
own:
Cause 1: Bad leaf spring in steering unit.
Solution 1: Internal problem; leaf spring.
Cause 2: The relief valve is stuck open.
Solution 2: Internal problem: relief valve.
• Poor Straight Line Steering Characteristics:
Cause 1: There is a bind in the steering column.
Solution 1: Binds may be created by angular or radial
misalignment between the steering column and the
steering unit. Binds may also be created by a lack of
axial clearance between the steering column and the
steering unit. Correct any situation that may create
friction or binding in the steering column.
Cause 2: Bad leaf spring in steering unit.
Solution 2: Internal problem; leaf spring.
14
Domestic Series 5000 Hydraulics
• Backlash
Cause 1: Wear or play between the steering column
and the cardan shaft.
Solution 1: If the wear is in the steering column,
replace the steering column (steering shaft per Cub
Cadet IPL). If the wear is in the cardan shaft, this is an
internal problem.
Cause 2: Bad leaf spring in steering unit.
Solution 2: Internal problem; leaf spring.
• Shimmy:
Cause 1: Air in steering system.
Solution 1: Repair any leaks in the hydraulic system.
Be aware that a leak on the suction side of the auxiliary
pump would entrain air into the hydraulic fluid, but may
not display significant fluid loss.
Cause 2: Worn mechanical connections.
Solution 2: Inspect the MFD and steering linkage for
sources of excessive play: worn wheel bearings, worn
tie rod ends, worn king pins, worn steering cylinder
mounting points, etc.... Replace the worn components.
• Slow Steering:
Cause 1: Insufficient fluid flow to the steering unit.
Confirm by testing the out-put of the auxiliary pump.
Solution 1: Repair of replace the auxiliary pump or
delivery line from the pump to the “P” port on the steering unit.
Cause 2: The priority valve in the steering unit is not
working properly. This valve normally maintains precedence of the steering system over all subsidiary systems (lift cylinder).
Solution 2: Internal problem; priority valve.
• The Steering Wheel Does Not Return to Center:
Cause 1: There is a mechanical bind in the steering
column.
Solution 1: Repair or adjust the steering column
(steering shaft) to eliminate the bind.
Cause 2: Bad leaf springs.
Solution 2: Internal problem; leaf springs.
Cause 3: The spool is pressing against the sleeve in
the steering unit.
• Steering Wheel Input Does Not Cause Steering cylinder to Move:
Cause 1: No fluid in the system.
Solution 1: Fill the system.
Cause 2: Worn steering cylinder / blow-by. Confirm
with flow test in line to cylinder.
Solution 2: Replace the steering cylinder.
• Heavy Impacts to Steering Wheel in Both
Directions:
Cause 1: The hydraulic hoses are incorrectly con-
nected; the hose that should connect to the “P” port is
connected to the “L” port or the “R” port.
Solution 1: Correct the hydraulic connections.
Cause 2: Incorrect setting of the cardan shaft to the
gear wheel (timing).
Solution 2: Internal problem; cardan shaft / gear wheel
timing.
Solution 3: Internal problem; relief valve causing too
much pressure to build, displacing the spool.
Cause 4: Binding between spool and sleeve caused by
fluid contamination.
Solution 4: Internal problem; contamination. If this is
a possibility, cleaning, fluid replacement, and filter
replacement will help prevent a repeat failure.
• Steering Action is Opposite of Input:
Cause 1: The “L” and “R” hoses are reversed at their
connections to the steering cylinder or steering unit.
Solution 1: Correct the connections of the hydraulic
lines from the steering unit to the steering cylinder.
Cause 2: Incorrect setting of cardan shaft to gear
wheel.
Solution 2: Internal problem; cardan shaft / gear wheel
timing.
15
Domestic Series 5000 Hydraulics
• Steering Power Too Low:
Cause 1: The relief valve is set too low or malfunction-
ing.
Solution 1: Internal problem; relief valve.
• Fluid Leakage:
Cause 1: The seal around the cardan shaft is leaking.
Solution 1: Internal problem; cardan shaft seal.
Cause 2: The port fittings are leaking.
Solution 2: Replace port adaptors or O-rings. Tighten
the fittings to a maximum torque of 221 in-lbs. (25 NM)
on the “T”, “R”, and “L” ports. Tighten the fittings to a
maximum of 239 in-lbs. (27 Nm) on the “P”, and “E”
ports.
7.6. Engine-off test: With the engine turned-off so
that no pressure is supplied by the auxiliary
pump, the pump within the steering unit should
work well enough in manual mode to turn the
front wheels from one steering stop to the other
(full travel) with roughly 2.75 turns of the steering
wheel.
NOTE: The tractor was engineered to comply
with German TUV directive #38stVZo. It will provide steering action without pressure from the
auxiliary pump, maintaining steering wheel force
within a specified limit.
7.10. Install the hydraulic test kit in either one of the
two hydraulic lines leading from the steering
pump to the steering cylinder.
7.11. Disconnect the hydraulic line between the steering unit and the steering cylinder using a 5/8”
wrench and a 3/4” wrench. See Figure 7.11.
Hydraulic line
(pressurized
to turn right)
Hydraulic line
(pressurized
to turn left)
Steering cylinder
Figure 7.11
7.12. Connect the test kit so that the pressure gauge
side (as opposed to the flow meter side) is near
the source (steering unit). See Figure 7.12.
7.7. If there is air in the system, it will not perform to
design intent:
• If there are any leaks in the steering hydraulics,
air will be drawn into the system, degrading performance.
• If the system has been disassembled for any
reason, the engine must be started to provide
pressure from the auxiliary pump. With auxiliary
pump pressure to assist, turn the steering wheel
lock-to-lock three times, to purge air from the
steering system.
• After the air is purged, the engine-off test can be
performed with validity.
7.8. If the hydraulic steering lacks speed, test the
auxiliary pump as described in the previous section of this manual.
7.9. Once it has been established that the auxiliary
pump is developing enough flow and pressure,
then test the steering unit.
Pressure test kit
installed in right
turn hydraulic line
Figure 7.12
7.13. Confirm that the test kit valve is all the way open,
and that no unsafe conditions will arise from
starting the tractor engine.
7.14. Start the engine, warm-up the engine and
hydraulic system, then position the throttle to
1,200-1,500 RPM.
16
Domestic Series 5000 Hydraulics
7.15. Have an assistant slowly turn the steering wheel
until the steering linkage hits the end of its travel.
Applying pressure to the steering wheel while
the linkage is at full lock will build pressure in the
system.
NOTE: The wheel can be turned in either direction to get a pressure reading.
NOTE: The steering pump is equipped with a
relief valve that will not permit the pressure to
rise above 1,087 to 1,160 PSI (75 to 80 Bars).
7.16. Observe the pressure reading on the test kit, at
full-lock. The pressure should be in the range of
1,087 to 1,160 PSI (75 to 80 Bars).
See Figure 7.16.
7.20. To check for blow-by, turn the steering wheel in
whichever direction causes the flow meter on the
test kit to rise:
• If the test kit is attached (as illustrated in figure
7.15) to the fitting at the base end of the cylinder,
turn the steering wheel to the right.
• If the flow meter is attached to the fitting at the
rod end of the steering cylinder, turn the wheel to
the left.
7.21. If the steering hits the end of its travel, builds terminal pressure, and the flow meter continues to
have a reading above zero, then fluid is blowingby the seals on the piston.
7.22. If the flow meter falls to zero and remains there
as pressure builds, then fluid is not blowing-by
the seals on the steering cylinder piston.
7.23. If blow-by exists, the steering cylinder is bad.
NOTE: A steering cylinder can get “blown-out”
by a steering pump with a relief valve that fails to
keep the pressure below 1,500 PSI (103 bars).
If this is the case, replacing the cylinder without
replacing the pump will result in rapid failure of
the replacement cylinder.
Figure 7.16
7.17. If steering pressure is low, and the auxiliary
pump has been confirmed to be functioning
properly, then the steering unit is the problem.
NOTE: Steering unit failure is a rare occurrence.
7.18. If the pressure is good between the steering unit
and the steering cylinder, but the steering system lacks power, then the steering cylinder is the
most likely hydraulic problem.
7.19. It is possible for the piston seals in the steering
cylinder to experience “blow-by” without creating
an externally visible leak.
7.24. If the hydraulic system (Auxiliary pump, steering
unit, cylinder, lines) is all in good order, then the
problem may be a mechanical bind in the steering linkage.
17
Domestic Series 5000 Hydraulics
t
8. HYDRAULIC LIFT CYLINDER AND CONTROL VALVE
8.1. If the hydraulic lift cylinder does not work or is
low on power, begin by making a visual inspection of the valve, cylinder, linkage, and hydraulic
hose. See Figure 8.1.
Pressure line from E por
Direct return to
transmission
Return through
check valve
Figure 8.1
8.2. The outboard plumbing and linkage connections
to the control valve are visible beneath the
fender. More complete inspection, diagnosis,
and service require fender removal.
8.3. The lift cylinder and the hydraulic hose that connects it to the control valve are visible beneath
the left fender. See Figure 8.3.
Line to
cylinder
8.4. If the lift cylinder is operable, run it through the
full range of travel to confirm that the feedback
rod is working correctly. Normal operating characteristics include:
• The the lift arms move up when the control lever
is moved back. The lift arms move down when
the control lever is moved forward.
• In all positions, the lift cylinder will apply only
upward force to the lift arms. It is a single-acting
cylinder.
• Downward travel is not under hydraulic force,
and is only caused by the weight of the lift arms
and any accessories mounted to them.
• At any point in their travel, the lift arms may be
manually lifted beyond the point that the hydraulic system is holding them at. They will always
“float”.
• Because the steering system has priority over
the lift cylinder, it is normal for the lift cylinder to
have less power when the steering system is in
motion.
8.5. Orientation of the valve: See Figure 8.5.
Valve end of line
to cylinder
Cylinder end of line, behind left wheel
Figure 8.3
Figure 8.5
• The flexible line to the outboard side of the valve
provides pressure from the steering pump.
• A flexible line from the bottom of the valve connects it to the lift cylinder.
• The steel line leading rearward from the front
port on the valve carries fluid directly back to the
transmission housing (reservoir).
• The steel line leading forward from the rear port
on the valve directs fluid to the return manifold,
and back to the transmission housing.
18
Domestic Series 5000 Hydraulics
8.6. Fluid movement:
• Fluid is constantly circulating from the auxiliary
pump, to the steering unit, through the valve,
then to the return manifold.
• When the valve is actuated to raise the lift arms,
it redirects fluid from this path to the lift cylinder.
• When the valve is actuated to lower the lift arms,
fluid is allowed to empty from the lift cylinder
through the valve, into the steel line leading from
the top of the valve to the transmission cover.
8.7. Control Linkage Description: The operator control handle pivots on a bracket bolted to the
frame. A pin on the valve link engages a slot in
the handle, above the handle pivot point. The
ratio of travel varies with the position of the handle, but when the pin is centered in the slot there
is a 10:1 ratio between the movement of the
handle and the movement of the pin. The top of
the valve link pivots on the valve mounting
bracket. Between the pin and the fulcrum is a
connection to the tubular link. There is a 3:1
ratio between the movement of the valve link
and the movement of the tubular link.
Control handle
Bracket
8.10. Confirm that the lift cylinder control valve is getting pressure from the steering pump:
• Remove any rear mounted attachments that are
supported by the lift arms or will interfere with
access to the lift cylinder and control valve.
• Remove the rear fenders.
• Lift and safely support the rear of the tractor.
• Remove the right rear wheel using a 21mm
wrench.
• Lower the lift arms to the bottom of their travel,
and confirm that the lift cylinder is fully retracted.
• Disconnect the flexible hydraulic line from the
bottom of the control valve using a 3/4” wrench
and a 5/8” wrench.
• Install the test kit with the flexible line connected
to the pressure gauge end of the kit, and the
control valve connected to the flow meter end of
the kit. See Figure 8.10.
From E port
To control valve
Tubular link
Pin
Figure 8.7
8.8. The effective movement ratio of 30:1between
the handle and the input to the control valve
allows precise movement of the three point lift
without the complexity of the shifting fulcrum
linkage used on the domestic Series 7000.
8.9. The category 1 three point hitch system on the
domestic Series 5000 tractor should be capable
of lifting 950 lbs. (430 Kg.), 24 in. (61 cm.)
behind the hitch. If it does not perform as
designed, use the following procedure to diagnose it.
Figure 8.10
8.11. Confirm that the test kit valve is all the way open,
and that no unsafe conditions will arise from
starting the tractor engine.
8.12. Start the engine, warm-up the engine and
hydraulic system, then position the throttle to
3,000 RPM.
19
Domestic Series 5000 Hydraulics
8.13. The flow meter should rise to 4 GPM (15 LPM)
and hold steady at that level. See Figure 8.13.
Figure 8.13
8.14. After the flow rate is established, lower the throttle setting to 1,200-1,500 RPM
8.15. Carefully close the valve on the test kit. It is not
necessary to move the lift cylinder to generate
pressure.
NOTE: Designed system pressure is 1,500 PSI
(103 Bars). Testing beyond this pressure subj ec t s t h e sy s te m t o n e ed l e ss o ve r - lo a d.
See Figure 8.15.
8.16. The flow should remain constant, while the pressure climbs to 1,500 PSI (103 Bars). Open the
valve a soon as the readings are confirmed.
NOTE: Remember, the flow varies with engine
RPM, but does not vary with pressure generated
unless the auxiliary pump is failing.
8.17. Turn off the engine. Retract the lift cylinder fully
to relieve pressure from the hydraulic system.
8.18. Remove the test kit from the line between the
steering unit and the lift control valve, and connect the hydraulic line to the control valve.
8.19. If the control valve is receiving full pressure from
the steering unit, but the lift cylinder lacks power,
perform a pressure test at the line between the
valve and the cylinder.
8.20. Install the test kit between the control valve and
the lift cylinder.
8.21. If the tractor is equipped with a mid-mount
mower deck, it will be necessary to disconnect
and remove the link that connects the three point
lift arm to the deck lift mechanism.
See Figure 8.21.
Deck lift link
Pressure
line to lift
cylinder
Figure 8.15
Figure 8.21
20
Domestic Series 5000 Hydraulics
8.22. Disconnect the flexible hydraulic line that leads
from the control valve to the lift cylinder using an
11/16” and a 3/4” wrench. See Figure 8.22.
Disconnect here
Figure 8.22
8.23. Connect the test kit to the 3/8” flare fittings. The
pressure gauge should be near the valve, and
the flow meter should be near the cylinder.
See Figure 8.23.
8.27. As the lift arms travel upward, note the reading
on the flow meter. It should be in the vicinity of 5
GPM (19 LPM). See Figure 8.27.
UP
4 GPM
No significant
pressure
Figure 8.27
8.28. Continue moving the arms up until they reach
the top end of their travel. Note the pressure
reading. See Figure 8.28.
To cylinder
To valve
Figure 8.23
8.24. Set the parking brake, place the gear selector in
neutral, open the flow valve on the gauge set all
the way, and confirm that no unsafe conditions
will be created by starting the tractor engine.
8.25. Start the engine, allow it to warm-up. Set the
throttle to maintain 3,000 RPM.
8.26. Move the hydraulic lift lever rearward to raise the
lift arms.
No flow
1,500 PSI
Figure 8.28
• The pressure should approach but not exceed
1,500 PSI (103 Bars).
• The flow will fall to zero as the pressure builds.
8.29. If the pressure delivered to the control valve is
low, the auxiliary pump has tested good, and the
hydraulic lines show no signs of physical damage or leakage, then the problem lies in the
steering unit.
21
Domestic Series 5000 Hydraulics
8.30. If the pressure delivered to the control valve is
sufficient, but the pressure delivered to the cylinder is low, then the problem is likely to be in the
control valve.
8.31. If the pressure delivered to the cylinder is sufficient, yet the cylinder does not perform adequately, look for leakage from the cylinder.
8.32. If the pressures are O.K., no leakage exists, yet
the cylinder does not perform adequately, there
may be a mechanical bind, or the operator may
be overloading the equipment.
9. LOADER VALVE
9.1. The simplest way to check pressure to the
attachment is by connecting the test kit to the
Quick Disconnect ports. See Figure 9.1.
9.2. If the performance problem is isolated to the
movement of one set of cylinders (boom or
bucket), connect the test kit to the set of couplings that is associated with that movement
(1 & 3) or (2 & 4).
9.3. With the test kit installed to test the boom, the kit
loops fluid from one boom connector to the
other. They hydraulic lines that lead to the cylinders that operate the boom will be left disconnected. For this test, the kit is not connected inline with the cylinders, and the cylinders will not
be in motion during the test.
9.4. After the test kit is connected, confirm that no
unsafe conditions will result from starting the
engine or operating the hydraulic system.
9.5. Open the flow valve on the test kit completely,
then start the engine, and set the throttle to
maintain 3,000 RPM.
9.6. With the test kit installed so that the pressure
gauge is near the boom-down fitting (green band
3d one in), and the flow meter is near the boomup fitting (blue band, outboard coupler), pushing
the loader valve forward to the detent will generate a reading on the flow meter of about 5.0
GPM (19.0 LPM) when the test kit flow valve is
open. Pressure will be zero. See Figure 9.6.
Figure 9.1
• The hydraulic lines are arranged as follows, from
the outboard inward when connected to a frontend loader:
1. Outboard coupling, blue band, boom up.
2. Second coupling in, yellow band, bucket dump.
3. Third coupling in, green band, boom down.
4. Furthest inboard, red band, bucket roll up.
• One female quick disconnect and one male
quick disconnect will be required on the test kit.
• Connect to alternating couplers, eg.: 1 & 3 to
check boom operation, or 2 & 4 to check bucket
operation.
5 GPM
NOTE: Pushing the loader valve lever all the
way forward, past the detent, will put the valve
into “float” mode. This is reflected by a flow
meter reading that falls to zero, and a pressure
gauge reading falls to zero.
NOTE: Pushing the loader valve lever forward,
but not all the way to the detent will produce
readings with less flow, but increased pressure.
Zero pressure
Figure 9.6
22
Domestic Series 5000 Hydraulics
9.7. Reducing throttle to the 1,200-1,500 RPM range,
observe the flow while pushing the loader valve
lever forward to the detent. The flow should be
around 5.0 GPM (19.0 LPM).
9.8. While holding the loader valve lever forward
gains the detent (but not into Float), slowly close
the flow valve on the test kit. See Figure 9.8.
Zero
flow
Valve closed
1,500 PSI
Figure 9.8
9.11. If the pressure varies slightly in above or below
1,500 PSI (103 Bars), the relief valve can be
adjusted. It is located on the top, outboard corner of the loader valve.
9.12. In order to adjust the relief valve, it is necessary
to remove the right side fender cover.
See Figure 9.12.
Fender
cover
Handles
Knob
Figure 9.12
NOTE: Because of the relief feature built into the
loader valve, as pressure approaches the relief
point of 1,500 PSI (103 Bars) more fluid will be
diverted to the return manifold. As more fluid is
diverted, the flow meter will show progressively
lesser readings while the pressure remains constant at 1,500 PSI (103 Bars). If the flow valve
on the test kit is closed completely, flow will stop
completely.
CAUTION: If pressure rises substantially above
1,500 PSI (103 Bars) discontinue the test immediately. Correct the pressure relief issue before
continuing.
9.9. The test described above will check the ability of
the hydraulic system to apply downward pressure to the boom. The test can be reversed, to
check lifting ability by reversing the connection
of the test kit and pulling the loader valve control
lever back instead of pushing forward.
9.10. The same procedures will work for testing the
controls for the roll operation of the bucket, but
the test kit will be connected to couplers 2 and 4
(second one in, red band and far inboard coupler, yellow band).
9.13. Remove the handles from the hydraulic lift control lever and the high-low range gear selector
lever by pulling them off.
9.14. Remove the knob and boot from the loader valve
control handle. The knob has normal right-hand
threads.
9.15. Remove the fender cover using a T-40 driver
from inside the fender. See Figure 9.15.
Figure 9.15
23
Domestic Series 5000 Hydraulics
9.16. Unbolting the loader valve bracket from the
frame of the tractor will provide additional
wrench clearance between the pivot bracket and
the fender. This can be done with a 1/2” wrench.
See Figure 9.16.
Loader valve bracket
Figure 9.16
9.17. It is necessary to unbolt the pivot bracket
assembly from the loader valve in order to get a
wrench on the relief valve adjustment screw.
The pivot bracket can be unbolted using a 3/8”
wrench. See Figure 9.17.
9.18. Once access is gained to the adjustment screw,
index the screw, jam nut, and housing using a
marker.
9.19. Loosen the jam nut using a 7/8” wrench and turn
the adjuster screw using a 7/16” wrench.
See Figure 9.19.
Figure 9.19
9.20. Make adjustments to the relief valve in singlefacet increments:
• Loosen the jam nut.
Adjustment screw
Jam nut
Pivot bracket
Loader valve bracket
Figure 9.17
• Make adjustment: 1/6th turn or less.
• Tighten jam nut.
• Install pivot bracket.
• Test relief valve pressure.
• Repeat as necessary.
•DO NOT “crank-up” the pressure beyond 1,500
PSI (103 Bars).
• Install the fenders when adjustment is completed.
9.21. The pressure readings at both sets of ports
should respond equally to adjustments made to
the relief valve. If there is substantial difference
between the pressures found at the two sets of
ports, there is an internal problem with the
loader valve.
9.22. If the loader valve does not respond to adjustment, or does not perform as described in this
section:
• Confirm that the pressure delivered to the loader
valve is adequate, and if not, why not. -or-
• Replace the valve.
24
Domestic Series 5000 Hydraulics
10. COMPONENT BREAKDOWN: AUXILIARY PUMP
NOTE: The auxiliary pump is to be replaced as a
unit if it fails. Disassembling it will VOID the
warranty. The pump has been disassembled
here to illustrate how it works.
NOTE: Individual pump components will not be
available through Cub Cadet.
10.1. The gear must be removed from the pump in
order to remove the pump from the transmission.
See Figure 10.1.
Auxiliary pump drive gear
Auxiliary pump
Nut
Lock tab
10.2. The back cover can be removed from the pump
by removing the four socket head cap screws.
See Figure 10.2.
Pump with back
Splined shaft
Figure 10.2
10.3. Removing the rear cover reveals an O-ring seal,
the splined shaft that transmits power to the tandem pump (when fitted), and four more socket
head cap screws.
cover removed
O-ring seal
Figure 10.1
• The gear is a taper-fit to the pump shaft, and it is
keyed to the shaft.
• The lock tab, key, and nut are included with the
pump.
• The nut and shaft have a non-standard metric
thread. They will not be commonly available.
• An O-ring seal and Ultra-black sealant are used
to seal the pump to the front of the transmission.
10.4. The second set of socket head cap screws holds
the two housing ends to the body of th e pu m p .
See Figure 10.4.
Housing end: back
Housing end:
mounting
Pump body
Figure 10.4
10.5. Both ends of the pump have O-ring type seals
where they meet the pump body.
10.6. The body contains a simple gear pump.
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