GILLIG LOW FLOOR, Руководство по обслуживанию

Страница: 323 / 506

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.