Cub Cadet Domestic Series 7000 Service Manual
www.mymowerparts.com
Service Manual
Domestic Series 7000 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 - 769-01634
12/2004
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
TABLE OF CONTENTS
Domestic Series 7000 Hydraulics
Orientation ................................................................................................................. 1
Hydrostatic Drive: Basic Operation ............................................................................ 4
External Checks ......................................................................................................... 6
Best Practices: Hydraulic Systems ............................................................................ 8
Flow and Pressure tests: Hydrostatic Drive ............................................................... 8
Auxiliary Pumps ....................................................................................................... 11
Steering Pump and Cylinder .................................................................................... 14
Hydraulic Lift Cylinder and Control Valve ................................................................ 18
Tandem Pump ......................................................................................................... 22
Loader Valve ............................................................................................................ 24
Component Breakdown: Auxiliary Pump (tandem pump similar) ............................. 26
Component Breakdown: Steering Unit ..................................................................... 28
Domestic Series 7000 MFD
Identify the 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 .............................................................................................. 57
Domestic Compact Dash and Steering Pump
Dash Panel Removal ............................................................................................... 59
The Dash Panel ....................................................................................................... 63
Steering Shaft and Pump: Sauer ............................................................................. 65
Steering Shaft and Pump: Ross ............................................................................... 67
Domestic Series 7000 Damped Driveshaft
Preparation: ............................................................................................................. 69
Driveshaft Removal .................................................................................................. 69
Electrical System
Electrical System ...................................................................................................... 72
Componants.............................................................................................................. 73
Eelstric Clutch and Fuel Pump.................................................................................. 81
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
Domestic Series 7000 Hydraulics
1. STANDARD HYDRAULIC SYSTEMS ON THE DOMESTIC SERIES 7000: ORIENTATION
NOTE: Subsections 1 and 2 of the Domestic
Series 7000 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
apendix 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 6.5 gallons (24.6 L) of Cub Cadet
Hydraulic Transmission Fluid (P/N: 737-3025
1Qt., 737-3062 1Gal., 737-3063 10 Qt., 7373035 5 Gal.).
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. The hydrostatic drive filter (P/N: 723-3014) is located on
the front surface of the hydrostatic pump.
See Figure 1.3.
1.4. The hydrostatic drive is a Sauer model BDU15.
It has an integrated gerotor charge pump that
draws fluid up the suction pipe from the base of
the transmission housing. See Figure 1.4.
Auxiliary
pump
Hydrostatic
drive pump
Figure 1.4
1.5. The steering and lift cylinder are powered by a
Sauer-Danfoss SKP 1/4.3 S auxiliary pump.
1.6. If hydraulically powered accessories are
installed, they are driven by a second auxiliary
pump that mounts to and is driven by the standard auxiliary pump. The add-on auxiliary pump
is a Sauer-Danfoss model SNP 1/7.8 S.
Second auxiliary
pump
Hydrostatic
Drive Filter
Hydraulic system
filter
Figure 1.3
NOTE: Other than sharing a reservoir, the
hydrostatic drive operates independently of the
rest of the hydraulic system.
K&T Saw Shop 606-678-9623 or 606-561-4983
NOTE: Domestic Series 7000 tractors produced
before 2004 included a single auxiliary pump as
standard equipment. Later tractors include both
auxiliary pumps and the valve used to operate a
front-end loader.
1
www.mymowerparts.com
Domestic Series 7000 Hydraulics
1.7. The steering pump, 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
pump
Figure 1.7
1.8. The steering pump 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.
1.11. The hydraulic fluid flow is as follows:
1.12. Through the pick-up tube from the transmission
sump and filter, to the auxiliary pump.
See Figure 1.12.
Auxiliary pump
Flow
Filter
Figure 1.12
1.13. Under pressure from the auxiliary pump the fluid
goes to the steering pump, connecting to the “P”
port on Sauer steering pumps. On Ross steering pumps, it connects to the “IN” port.
1.9. The lift cylinder is operated by a control valve
and feedback rod under the right rear fender.
See Figure 1.9.
Direct return
To lift cylinder
1.10. The control valve directs fluid pressure to a single-acting hydraulic cylinder that lifts the threepoint lift arms.
To return manifold
From Steering
unit
Figure 1.9
Line to
steering
unit
Auxiliary pump
(steering and
lift cylinder)
Figure 1.13
2
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
1.14. The steering unit distributes pressure to the
steering cylinder according to the position of the
steering wheel. On Sauer pumps this involves
the ports labeled “L” and “R”. See Figure 1.12.
Sauer steering unit:
note labeled ports
Figure 1.14
1.15. On Ross pumps, this involves the ports labeled
“LT” and “RT”. See Figure 1.14.
1.16. The power steering unit is first in line, and has
priority over the rest of the system. From the
steering unit, the fluid may follow one of two
return paths:
1.17. The fluid may pass through the return manifold,
through the oil cooler, then back to the transmission. See Figure 1.17.
Return
manifold
To cooler
From lift
valve
From steering unit
“T” port on Sauer
“OUT” port on Ross
Unused ports
capped
Figure 1.17
LT
OUT
AUX
Figure 1.15
RT
IN
1.18. The oil cooler is located on the front of the radiator. See Figure 1.18.
Oil
cooler
Figure 1.18
3
K&T Saw Shop 606-678-9623 or 606-561-4983
e
www.mymowerparts.com
Domestic Series 7000 Hydraulics
1.19. If the fluid is required by the lift cylinder, it will go
to the bottom port of the lift valve instead of the
return manifold.
1.20. The lift valve sends fluid to the single-acting lift
cylinder when operator demand and the feedback rod direct it to do so. See Figure 1.20.
Feedback
rod
Lift
cylinder
Figure 1.20
2. HYDROSTATIC DRIVE: BASIC OPERATION
2.1. The input shaft to the D15U 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.
Auxiliary
hydraulic
pump
Hydro.
Input
shaft
for PTO
1.21. Fluid not required to lift the cylinder will be
directed back to the transmission through the
return manifold, via the cooler. See Figure 1.21.
Line from return
manifold and oil cooler
Direct return line from
lift cylinder (when lowered)
To return
manifold
Lift valve
Figure 1.21
1.22. Excess fluid volume beyond normal return flow
rate is generated when the lift arms are lowered.
This flow is exhausted directly back into the
transmission housing.
Figure 2.2
2.3. The input shaft also turns a gerotor style charge
pump and an axial piston variable displacement
hydraulic pump. See Figure 2.3.
Fixed displacement
motor
Charge check valves
Figure 2.3
NOTE: Figure 2.3 is a similar model hydrostatic
drive unit with some see-through components.
Charg
pump
4
K&T Saw Shop 606-678-9623 or 606-561-4983
S
www.mymowerparts.com
Domestic Series 7000 Hydraulics
2.4. 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.
2.5. The hydro. control arm (scissors bracket) moves
a swash plate that controls the output of the
pump: 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 swashplate.
• 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.
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.
2.8. The charge pump maintains a supply of pressurized fluid to the variable displacment 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
varaible displacment pump thorugh 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 ths 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 bee seen with minimal disassembly.
wash plate
angle
Pistons
5
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
3. EXTERNAL CHECKS
NOTE: Linkage adjustment procedures are cov-
ered in the 2003 Cub Cadet Technical Handbook, pages 6-129 through 6-131.
3.1. Remove the fender cover using a phillips head
screwdriver and a 1/2” wrench. See Figure 3.1.
Fender cover
Bolts
Holes for
screws
Foot pad
Figure 3.1
3.3. If the brake and drive pedals “fight” with each
other, the drive control linkage is out of adjustment. See Figure 3.3.
Brake shaft
assembly
3.4. If the tractor fails to achieve normal ground
speed, and the hydro pump emits an unusual
amount of noise, check for brake drag:
Forward shaft
assembly
Figure 3.3
Hydro control
rod
Adjustment
ferrule
NOTE: It will be necessary to pry-up the inside
edges of the black rubber floor pads to get the
fender cover off.
3.2. If the transmission creeps, or the tractor fails to
achieve normal ground speed, check the neutral
control adjustment and control linkages to the
hydro. See Figure 3.2.
Shoulder
bolt
Neutral
return
assembly
• 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.
• The left and right brakes can be checked individually by jacking-up the rear of the tractor and
attempting to rotate the rear wheels individually.
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, remove the wheel and brake
assembly on the side that drags. Inspect the
brake assembly.
NOTE: Complete brake adjustment procedures
can be found in the 2003 Cub Cadet Technical
Handbook, page 6-131 through 6-133.
Figure 3.2
NOTE: Complete neutral control adjustment pro-
cedures can be found in the 2003 Cub Cadet
Technical Handbook, page 6-129 through 6-131
K&T Saw Shop 606-678-9623 or 606-561-4983
6
www.mymowerparts.com
Domestic Series 7000 Hydraulics
3.5. 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.
3.6. Check the fluid by removing the plug / fluid level
gauge on the back of the transmission. Check
the level, and compare the fluid to a sample of
Cub Cadet Hydraulic Transmission Fluid. Topup or replace the fluid as necessary.
See Figure 3.6.
3.8. Visually inspect the suction tube that feeds fluid
to the hydrostatic drive from the sump of the
transmission. If it is kinked or crushed, replace
it. See Figure 3.8.
Hydro.
Suction tube
Filter
Figure 3.8
NOTE: Drain the transmission fluid before
removing the suction tube.
Figure 3.6
3.7. Replace the hydrostatic filter if there is any question of it’s condition.
3.9. Check that the set screw holding the control arm
to the hydro control shaft has not backed-out,
worn, or sheared. See Figure 3.9.
Neutral
return arms
Set screw
Hydro control arm
Figure 3.9
7
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 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. This should achieve
a fluid temperature of 180 deg. f. (82 deg. c.) 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
5.1. If the problem is not revealed by any of the
external checks, check the charge-pump pressure.
5.2. Clean the area surrounding the set screw in the
top of the hydrostat. Remove the set screw
using a 3/16” allen wrench. See Figure 5.2.
Port
Set screw
Figure 5.2
NOTE: 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: The port accessed by removing the set
screw will be pressurized by the charge pump
when the engine is running.
5.3. Connect a gauge that is capable of reading
1,000 PSI (69 Bars) to the port that the set screw
was removed from. The port is threaded to
accept a 1/8” pipe thread.
NOTE: The gauge should be equipped with a
hydraulic snubber or needle valve to damp the
pressure pulses created by the pump.
CAUTION: Confirm that no unsafe conditions
will be created by starting the engine or operating the drive system before perfoming the test.
Remember that the front drive axle on fourwheel drive Domestic Series 7000 tractors will
engage automatically.
8
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
5.4. The charge pump should generate between 70
and 150 PSI (4.8 to 10.3 Bars) @ 1,200 RPM.
See Figure 5.4.
Figure 5.4
5.5. As the RPM is increased to the governed top noload sped, the pressure may increase somehwat. If pressure goes down as engine speed
increases, turn-off the engine and determine the
cause. See Figure 5.5.
5.7. Assuming the supply to the pump is good, low
pressure or a complete lack of pressure at this
port indicates a charge pump that is not working.
5.8. The charge pump could be disabled by a sticking charge pump relief valve. See Figure 5.8.
Figure 5.8
• This valve is located under the hexagonal cap
next to the pressure test port for the charge
pump.
Figure 5.5
5.6. Operate the system at full input and output
speeds in both directions,and confirm that
charge pressure is maintained.
• The valve consists of a light compression spring
and a ball that seats in a bore.
• The cap can be easily removed to inspect the
valve using a 5/8” wrench. Failure of this valve
would be unusual, but if the ball fails to seat,
charge pump pressure will leak off.
NOTE: The charge pump is not available separately through Cub Cadet.
NOTE: The reason for testing the charge pump
is to help distinguish between a problem within
the hydrostatic drive and a problem that lies
elsewhere in the drive system.
9
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
5.9. If the charge pump is working, but drive has
been lost in one direction only, one of the charge
check valves may not be working.
See Figure 5.9.
Charge
check valves
Figure 5.9
• There is a charge relief 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.
5.11. When removed, each charge relief valve comes
out as a cartridge. See Figure 5.11.
Figure 5.11
5.12. The output of the variable displacement pump is
dependent upon the performance of the check
valves
5.13. If the hydrostatic drive must be replaced, it can
be removed from the tractor without removing
the fenders.
• The charge check valves are located on either
side of the hydrostatic drive.
• The one on the left side maintains pressure in
the forward circuit, the one on the right side
maintains pressure in the reverse circuit.
5.10. The charge check valves can be removed using
a 5/16” allen wrench.
NOTE: The one on the right side is easy to
reach. The one on the left side will be obscured
by the auxiliary pump and a steel hydraulic line if
the tractor is equipped with a second auxiliary
pump to operate a loader or backhoe.
10
K&T Saw Shop 606-678-9623 or 606-561-4983
e
www.mymowerparts.com
Domestic Series 7000 Hydraulics
6. AUXILIARY PUMPS
6.1. The standard auxiliary pump provides pressure
for the hydrostatic power steering unit and the lift
cylinder attached to the three-point hitch.
6.2. Domestic Series 7000 tractors produced before
the 2004 season came with a single auxiliary
pump. See Figure 6.2.
Auxiliary pump
to drive steering
and lift cylinder
Hydraulic pressure
to steering unit
6.5. As with the hydrostatic drive, confirm that the
pump drive and supply are intact before drawing
conclusions about the pump itself by making
these preliminary checks:
• 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.
• If there is no hydraulic pressure, confirm that the
pump drive is intact. The auxiliary pump is
driven by a series of gears at the front of the
transmission.
6.6. The filter and suction tubes are easily reached
for inspection with little or no disassembly.
See Figure 6.6.
Figure 6.2
6.3. Current production Domestic Series 7000 tractors are fitted with a tandem auxiliary pump to
power attachments such as a back-hoe or frontend loader. See Figure 6.3.
First auxiliary
pump
Tandem
auxiliary pump
Figure 6.3
Hydraulic pressur
to steering unit
Hydraulic
pressure to
loader valve
Suction tube for
hydrostatic drive
Hydraulic
filter
Suction tube
for auxiliary
pump
Suction tube
for tandem
pump
Figure 6.6
6.4. If performance of hydraulic features (steering or
lift cylinder) or attachments (front-end loader or
back-hoe) is poor, it is necessary to confirm that
sufficient hydraulic power is being supplied by
the pump that drives it.
K&T Saw Shop 606-678-9623 or 606-561-4983
11
www.mymowerparts.com
Domestic Series 7000 Hydraulics
6.7. If the tractor has a speed sensor mounted in the
transmission cover, it is a hall effect device that
employs the auxiliary pump drive gear as a tonering to generate a tachometer signal. This was
done on early (2003 production) tractors.
See Figure 6.7.
Eary style
speed sensor
Auxiliary pump
drive gear
NOTE: see-through
transmission coverissi
Figure 6.7
6.11. The rear fenders must be removed to access the
auxiliary pump itself. Fender removal is detailed
in the 2003 Cub Cadet Technical Handbook on
pages 6-21 through 6-27.
6.12. If the tractor has an engine mounted speed sensor, the pump drive can be inspected with a
flashlight and probe.
6.13. Remove the pipe plug that fills the hole previously used for the speed sensor.
6.14. The auxiliary pump drive gear should be visible
through the hole. See Figure 6.14.
Plug (removed)
Auxilieary pump
drive gear (visible
through port)
6.8. On tractors with the transmission mounted
speed sensor, if the tachometer works, the pump
drive is confirmed to be working as well.
6.9. The speed sensor is visible without removing the
fenders. It is located on the transmission cover,
directly above the auxiliary pump.
6.10. Current production uses an engine-mounted
speed sensor, or an ignition generated tachometer signal on gasoline engines. See Figure 6.10.
Engine
mounted
speed sensor
(front of
crankshaft on
CAT engine)
Transmission
cover
Figure 6.14
6.15. To test the auxiliary pump that powers the steering and lift cylinder, use a flow and pressure
gauge set. See Figure 6.15.
Figure 6.10
NOTE: Equipment will vary from shop to shop,
but operating principles are similar.
12
Figure 6.15
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
6.16. Disconnect the output line from the top of the
pump using a 3/4” wrench and a 9/16” wrench.
6.17. 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.
6.18. 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.
See Figure 6.18.
Flow
meter
Flow
valve
Pressure
guage
• Set the throttle to maintain an engine speed in
this range, and note the reading on the flow
meter.
6.21. Close the flow valve until the pressure gauge
reads 1,500 PSI (103 Bar). Note the flow reading. See Figure 6.21.
Figure 6.21
Figure 6.18
6.19. Start the engine, allow the engine and hydraulics
to warm-up.
6.20. Performance:
• The SKP1/4.3 S auxiliary pump does not contain
a relief valve. It is capable of producing roughly
3600 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 Gal./min. (15 L/min.) at an engine speed of
3,000 RPM, with no load applied.
6.22. As soon as the flow reading is noted, open the
the flow valve completely, relieving pressure
from the system. Turn -off the engine.
6.23. 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.
• Flow will vary with engine speed, but pressure
tests can be done at lower engine speeds:
1,200-1,500 RPM.
K&T Saw Shop 606-678-9623 or 606-561-4983
13
www.mymowerparts.com
Domestic Series 7000 Hydraulics
7. STEERING PUMP AND CYLINDER
7.1. Two steering units have been used in domestic
Series 7000 production: one produced by Sauer/
Danfoss, and one produced by Ross (ParkerHannifin).
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.
7.2. Identification: The Sauer OSPM 63 PB unit has
a round body. The Ross steering unit has a
square body. See Figure 7.2.
• High Effort Required to Turn Steering Wheel:
Cause 1: The auxiliary pump is not supplying sufficient
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.
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.
Sauer Steering Unit Ross Steering Unit
Figure 7.2
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.
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 elswhere in the system.
Internal problems dictate replacement of the
steering unit.
Solution 2: Internal problem: relief valve.
• Poor Straight Line Steering Charactersistics:
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.
• 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.
14
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
• 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.
• 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.
• 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.
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:
• 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.
• 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 precidence of the steering system over all subsidiary systems (lift cylinder).
Solution 2: Internal problem; priority valve.
Cause 1: The “L” and “R” hoses are reversed at their
conections to tht 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.
• 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.
Soluton 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.
15
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
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.
7.7. 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 preformance.
• 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.
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.
• 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.
7.10. Install the hydraulic test kit in either one of the
two hydraulic lines leading from the steering
pump to the steering cylinder.
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
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 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.
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) for the Sauer
unit, and 1,450 PSI (100 Bars) for the Ross unit.
See Figure 7.16.
Figure 7.16
• If the test kit is attached (as illustrated in figure
7.11) 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.
7.24. If the hydraulic system (Auxiliary pump, steering
unit, cylinder, lines) is all good, then the problem
may be a mechanical bind in the steering linkage.
NOTE: The wheel can be turned in either direction to get a pressure reading.
NOTE: The Sauer 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). The Ross steering pump is equipped with
a relief valve that will not permit the pressure to
rise above 1,450 PSI (100 Bars).
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.
7.20. To check for blow-by, turn the steering wheel in
whichever direction causes the flow meter on the
test kit to rise:
17
K&T Saw Shop 606-678-9623 or 606-561-4983
)
www.mymowerparts.com
Domestic Series 7000 Hydraulics
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 cylinder, linkage, and feedback rod.
See Figure 8.1.
Feedback
rod
Lift
cylinder
Figure 8.1
8.2. 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 travel of the lift arms should be directly
related to the height of the lift arms.
• 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”.
Hydraulic line
from control valve
8.3. Orientation of the valve: See Figure 8.3.
Return line directly to
transmission housing
(when arms are
owered
Fluid return line
via: return manifold
and cooler
Hydraulic line
from
steering unit
Hydraulic
line to cylinder
Figure 8.3
8.4. Hydraulic Connections:
• The flexible line to the bottom of the valve provides pressure from the steering pump.
• A second flexible line leads back to the lift cylinder.
• The steel line leading from the top of the valve
forward directs fluid through the oil cooler, via
the return manifold, and back to the transmission
housing.
• Fluid is constantly circulating through this path,
from the steering pump, 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 steel line leading from the top of the
valve to the transmission cover.
• 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.
K&T Saw Shop 606-678-9623 or 606-561-4983
18
www.mymowerparts.com
Domestic Series 7000 Hydraulics
8.5. Control Linkage Description:
• The feedback rod and link assembly governs the
motion of the lift arms. It transmits motion from
the lift arms back to the pin that provides the fulcrum point that the bottom end of the feedback
link pivots on.
• A pin on the operator controlled linkage engages
the top end of the feedback link.
• The valve link is connected to the center point of
the feedback link.
• The control input to the valve is determined by
the balance between the two ends of the feedback link.
• As the arms aproach the position set by the
operator controlled lever, the feedback rod
moves the feedback link back to a position that
returns the control valve to neutral.
8.6. If a high pitched squeal emanates from the control valve after repositioning the lift arms, the
feedback rod is not working properly.
8.7. Inspect the feedback rod and link. If there is any
sign of damage (bent rod, worn ferrule, stripped
threads, etc....) or corrosion, repair the linkage.
See Figure 8.7.
8.9. The category 1 three point hitch system on the
domestic Series 7000 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.
8.10. Confirm that the lift cylinder control valve is getting pressure from the steering pump:
8.11. Remove any rear mounted attachments that are
supported by the lift arms or will interfere with
access to the lift cylinder and control valve.
8.12. Lift and safely support the rear of the tractor.
8.13. Remove the right rear wheel using a 21mm
wrench.
8.14. Lower the lift arms to the bottom of their travel,
and confirm that the lift cylinder is fully retracted.
See Figure 8.14.
Operator
controlled
linkage
Feedback
link
Feedback
rod
Fulcrum point
(moves with feedback rod)
Figure 8.7
8.8. The length of the feedback rod is not adjustable.
Only the load on the compression springs at
each end is adjustable. The locking nuts should
each be.25 inch (.65 cm.) from the end of the
rod.
Control input to valve
Figure 8.14
8.15. Disconnect the flexible hydraulic line from the
bottom of the control valve using a 3/4” wrench
and a 5/8” wrench.
19
K&T Saw Shop 606-678-9623 or 606-561-4983
www.mymowerparts.com
Domestic Series 7000 Hydraulics
8.16. 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 8.16.
Test kit connection
to lift control valve
Figure 8.16
8.17. Confirm that the test kit valve is all the way open,
and that no unsafe conditions will arise from
starting the tractor engine.
8.21. Carefully close the valve on the test kit. Do not
close the valve all the way. It is not necessary to
move the lift cylinder to generate pressure.
See Figure 8.21.
Figure 8.21
8.22. 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.
8.18. Start the engine, warm-up the engine and
hydraulic system, then position the throttle to
3,000 RPM.
8.19. The flow meter should rise to 4 GPM (15 L/m)
and hold steady at that level. See Figure 8.19.
Figure 8.19
NOTE: Remember, the flow varies with engine
RPM, but does not vary with pressure generated
unless the auxiliary pump is failing.
8.23. Turn off the engine.
8.24. 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.
8.25. Install the test kit between the control valve and
the lift cylinder. See Figure 8.25.
NOTE: Fender removal is not necessary
Test kit installed in-line between
valve and cylinder.
8.20. After the flow rate is established, lower the throttle setting to 1,200-1,500 RPM
K&T Saw Shop 606-678-9623 or 606-561-4983
Figure 8.25
20
www.mymowerparts.com
Domestic Series 7000 Hydraulics
8.26. 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.
8.27. Start the engine, allow it to warm-up. Set the
throttle to maintain 1,200-1,500 RPM.
8.28. Have an assistant move the hydraulic lift lever
rearward to raise the lift arms.
8.29. As the lift arms travel upward, close the valve on
the test kit. Note the pressure. See Figure 8.29.
8.30. The pressure should approach but not exceed
1,500 PSI (103 Bars).
8.31. 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.
8.32. 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.
8.33. If the pressure delivered to the cylinder is sufficient, yet the cylinder does not perform adequately, look for leakage from the cylinder.
8.34. If all 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.
Figure 8.29
NOTE: It will take several successive steps to
close the valve far enough to reach maximum
pressure:
• Close the valve partially while the cylinder is
extending.
• Note the pressure reading and the color of the
highest exposed colored band on the valve.
• Open the valve completely.
• Lower the lift arms completely.
• Close the valve to the point that was reached on
the previous lift, as indicated by the exposed colored bands.
• Extend the cylinder, and close the valve further
to build more pressure: repeat the process until
maximum pressure is achieved.
• Open the valve on the test kit immediately after
the pressure reading is noted.
21
K&T Saw Shop 606-678-9623 or 606-561-4983
m
www.mymowerparts.com
Domestic Series 7000 Hydraulics
9. TANDEM PUMP
9.1. Attachments are covered in a separate section.
This section covers the portions of the hydraulic
system that remain permanently attached to the
tractor.
NOTE: Unless stated otherwise, it is not necessary to remove the fenders to perform the tests
described in this section. Some of the figures in
this section show the fenders removed. This
was done for photographic purposes, not for
mechanical purposes.
9.2. If there is a performance problem with an attachment controlled by the loader valve, confirm that
adequate flow and pressure are being delivered
to the loader control valve by the tandem pump.
9.3. The output of the tandem pump may be checked
at the line to the loader valve, or at the line from
the loader valve to the return manifold.
See Figure 9.3.
Return
manifold
9.5. Disconnect either hydraulic tube between the
bracket / bulkhead fitting on the frame, and the
loader valve. Use a 7/8” wrench and a 1”
wrench to disconnect the tube. See Figure 9.5.
Pressure line fro
tandem pump
Line to return
manifold
Figure 9.5
9.6. Install the test kit with the pressure gauge nearest the source of pressure.
Bulkhead fittings
Figure 9.3
NOTE: Because there is no power beyond from
the loader control valve, there is only one return
path for the hydraulic fluid.
NOTE: A pressure and flow test performed in
either line will yield valid results.
9.4. To gain easy access to the loader valve:
• Lift, and safely suppport the right rear of the tractor.
• If testing on the line from the pump to the valve,
the pressure gauge should be near the pump.
• If testing on the line from the valve to the return
manifold, the pressure gauge should be near teh
valve.
9.7. Confirm that no unsafe conditions will result from
starting the tractor and operating the hydraulic
system. Confirm that the valve on the test kit is
fully open.
9.8. Start the engine, and allow the hydraulic fluid to
warm-up if necessary.
9.9. Set the throttle to maintain 3,000 RPM.
• Remove the right rear tire using a 21mm
wrench.
K&T Saw Shop 606-678-9623 or 606-561-4983
22
www.mymowerparts.com
9.10. Observe the flow rate. It should be in the 6.5
GPM (25 L/m) range. See Figure 9.10.
25 L/m flow
Flow valve open
No pressure
Figure 9.10
Domestic Series 7000 Hydraulics
• System pressure is regulated by a relief valve in
the loader valve.
• In this test, we have effectively disabled that
relief valve. Use caution not to overload the
system by closing the valve farther or longer
than necessary to test pump performance.
9.13. If the tandem pump fails to perform as specified,
confirm that the problem is not due to external
factors such as:
• Insufficient or incorrect working fluid.
• Blocked filter.
• Pump drive failure.
• Crushed, kinked, or blocked suction tube.
• Crushed, kinked or blocked return path.
9.14. If external factors do not account for the lack of
performance, replace the tandem pump.
9.11. Set the throttle to maintain 1,200-1,500 RPM,
and observe the flow rate.
9.12. Close the valve on the test kit until it is confirmed
that the pump will generate at least 1,500 PSI
(103 Bars). Observe the flow rate.
See Figure 9.12.
Pressure builds
Flow
remains
steady
Flow valve partially closed
Figure 9.12
• The flow rate should not be significantly reduced
from the initial 1,200-1,500 RPM observation by
the increase in pressure.
• Like the auxiliary pump, the tandem pump is
capable of generating pressure well in excess of
the intended operating pressure of the rest of the
system.
K&T Saw Shop 606-678-9623 or 606-561-4983
23
Loading...