Hydraulic System
323
Back Pressure
Normal system back pressure will be 25 to 75 psi with the engine idling and the steering wheel station-
ary. Check the back pressure with the system at normal operating temperature.
Heat build up can be caused by abnormally high back pressure. Restrictions in fittings, too many fittings
in a line, or a line that is too long and too small in diameter to carry the fluid flow can contribute to high
back pressure.
Operating Temperature
The steering system fluid temperature is best checked after two hours of normal operation. An ideal
operating temperature should range between 140° and 160° F (60° to 71° C). Normal operation in this
range will allow for intermittently higher temperatures which will be encountered during periods of
heavy steering usage.
Aerated Fluid
Visually check for the presence of air mixed with the fluid in the steering system. The fluid should be
clear. Any signs of frothing indicate air entry and steering performance will be affected. Carefully check
for leakage on the suction side of the hydraulic pump. Drain and refill the system and bleed for air fol
-
lowing the procedure under final adjustment.
Before any steering gear repairs are attempted, the above hydraulic supply evaluations should be com-
pleted and corrections made as required.
Summary of Contents for LOW FLOOR
Page 18: ...Specifications 18...
Page 58: ...Preventive Maintenance 58...
Page 110: ...Engine 110...
Page 138: ...Transmission Driveline Rear Axle 138...
Page 182: ...Suspension 182...
Page 260: ...Air System 260...
Page 420: ...Electrical System 420 Deutsch DT Series Connectors...
Page 421: ...Electrical System 421...
Page 422: ...Electrical System 422 Deutsch HD 10 Series Connectors...
Page 423: ...Electrical System 423...
Page 424: ...Electrical System 424 Deutsch HD 30 Series Connectors...
Page 425: ...Electrical System 425...
Page 442: ...Heating Air Conditioning 442...
Page 492: ...Body and Interior 492 Figure 11 33 USSC Seat Assembly...
Page 493: ...Body and Interior 493 Figure 11 34 USSC Seat Suspension Assembly...
Page 495: ...Body and Interior 495 Figure 11 37 Seat Air Connections...