- Apply the parking brake and block the vehicle wheels.
- Start the engine and charge the system to the air compressor governor
cut-out point.
- Turn off the engine.
- Drain the air pressure from the supply reservoir. Refer to
Draining Reservoirs
.
Important: Applying the brakes repeatedly drains the supply air reservoir pressure.
This may cause the brakes to appear sluggish.
- Have an assistant apply and release the brake pedal two times.
- Verify that the front and rear slack adjusters move smoothly and
promptly.
• | If the front brakes are sluggish or fail to move, overhaul or
replace the single check valve at the front service air reservoir. |
• | If the rear brakes are sluggish or fail to move, overhaul or replace
the single check valve at the rear service air reservoir. |
- Start the engine.
- Charge the system air pressure to the governor cut-out point.
- Stop the engine.
- Remove the wheel blocks.