SkyTrak 8042 Service Manual - Manual (Page 468)

8.53 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
Not
OK
Not
OK
If there is no four-wheel or crab
steering, check the steer select valve.
Inspect/replace the steer select valve.
Check the steer select switch and wiring.
Refer to the steering circuits and
components in Section 9.7, “Electrical
System Troubleshooting,” and Section
9.14, “Switches and Solenoids.”
If OK
Not
OK
Not
OK
Not
OK
If there is no steering, check the
steering system electrical components.
If OK
Not
OK
Front or rear wheels are not parallel
in front or four-wheel steering mode.
Perform indexing procedure on vehicle.
Check wheel alignment.
Not
OK
Check the steer select valve. Replace the steer select valve.
If OK
Refer to the steering circuits and
components in Section 9.7, “Electrical
System Troubleshooting,” and Section
9.14, “Switches and Solenoids.”
Check the pressure at the “PSG” port of the
secondary function manifold.
Not
OK
Check packing in steering cylinders.
If OK
Repair/replace steering cylinder.
If OK
If OK
Not
OK
Not
OK
Not
OK
Not
OK
Not
OK
Check the front and rear steering cylinders
for packing leaks.
Repair/replace steering cylinder(s).
If OK
Check pump flow.
If OK
Not
OK
Check the power steering unit. Replace power steering unit.
If OK
Check the main system pressure on the
main control valve.
Adjust/replace the relief valve.
Check the pump compensator pressure.
Consult factory to adjust the
compensator pressure at the pump.
Check the shuttle valve. Replace shuttle valve.
If OK
If OK
Repair/replace pump.
If OK
If OK
Not
OK
Check the load sense pressure at the “PLT”
port on the secondary function manifold.
Adjust/repair/replace the pressure reducing
valve on secondary function manifold.
Not
OK
Check that the check valve fitting at the
power steering unit is operating properly.
Replace check valve fitting.
If OK
Adjust/repair/replace the pressure reducing
valve on secondary function manifold.
Refer to Section 5.3.8, “ZF Axle Repair
Manuals,” for proper ZF Axle Repair
Manual for further information.