Air Brake Quick Release Valve Operational Check Operational Check

1. Block the wheels.
2. Start the engine.
3. Charge the system air pressure to the governor cut-out point.
4. Stop the engine.
5. Ensure that the service brakes apply fully when you depress the brake pedal.
6. Verify that the brakes promptly release when you release the brake pedal.

If the brakes are sluggish, check that air vents through the exhaust port when you release the brakes. If the brakes do not promptly release, repair or replace the quick release valve.

7. Remove the wheel blocks.

Air Brake Quick Release Valve Operational Check Leakage Test

1. Block the wheels.
2. Start the engine.
3. Charge the system air pressure to the governor cut-out point.
4. Stop the engine.
5. Ask an assistant to apply the brake pedal.



6. Inspect the exhaust port for air leakage. Air leakage of a 25.4 mm (1 inch) bubble in 3 seconds is acceptable. If the air leakage is excessive, overhaul or replace the quick release valve.
7. Inspect the upper and the lower valve body for air leakage. Air leakage is not permissable. If any bubbles appear, overhaul or replace the quick release valve.
8. Remove the wheel blocks.