GILLIG LOW FLOOR, Руководство по обслуживанию

Страница: 219 / 506

29
Air System
Operating and Leakage Checks
A change in vehicle braking characteristics or a low pressure warning may indicate a malfunction in
one or the other brake circuit, and although the vehicle air brake system may continue to function, the
vehicle should not be operated until the necessary repairs have been made and both braking circuits,
including the pneumatic and mechanical devices, are operating normally. Bendix recommends that it be
replaced with a new or remanufactured unit.
Always check the brake system for proper operation after performing
brake work and before returning the vehicle to service.
operating check
Check the delivery pressure of both primary and secondary circuits using accurate test gauges.
The pedal will not be in a “normal” position until the air brake system
is pressurized. The pedal will rise to its normal position as the brake
system air pressure builds up.
Depress the treadle to several positions between the fully released and fully applied positions, and check
the delivered pressure on the test gauges to see that it varies equally and proportionately with the move -
ment of the brake pedal.
After a full application is released, the reading on the test gauges should fall off to zero promptly. It
should be noted that the primary circuit delivery pressure will be about 2 psi greater than the secondary
circuit delivery pressure with both supply reservoirs at the same pressure. This is normal for this valve.
leakage check
1. Make and hold a high pressure (80 psi) application.
2. Coat the exhaust port and body of the brake valve with a soap solution.
3. Leakage permitted is a one inch bubble in 3 seconds. If the brake valve does not function as
described above or leakage is excessive, it is recommended that it be replaced with a new or
remanufactured unit, or repaired with genuine Bendix parts available by calling your Gillig Parts
representative and at authorized Bendix parts outlets.