GILLIG LOW FLOOR, Service Manual

Page: 333 / 506

Hydraulic System
333
Possible Cause Remedy
Problem: Hydraulic fluid milky or white in appearance
Clean vent system or replace cap venting as-
sembly.
A. Water entry through reservoir
system
Possible Cause Remedy
Problem: Fluid leaking at supply pump
Replace seal A. Damaged seal
Check operating temperature. Repair pump. B. Seal damaged by heat
Problem: Hydraulic pump making noise (continued)
Possible Cause Remedy
Align and replace oil seal and bearings if dam-
aged by shaft misalignment.
C. Coupling misalignment
Leakage between manifold or reservoir at
replenishing hole due to O-ring damage. Reser-
voir inlet tube to pump cover O-ring should be
carefully examined for damage and replaced if
necessary.
D. Reservoir or manifold seal leakage
Possible Cause Remedy
Problem: Hydraulic fluid forced out of reservoir
Bleed air from system A. Air in system
Check pump according to instructions in
“Power Steering Hydraulic System Diagnosis”
section.
B. Faulty supply pump (cavitation)
Adjust relief plungers
C. Steering gear relief plungers not
properly adjusted
Check pump according to instructions in
“Power Steering Hydraulic System Diagnosis”
section.
D. Operating temperature high