- Block the wheels.
- Start the engine.
- Charge the system air pressure to the governor cut-out point.
- Pull out the system park knob and release the brake pedal.
- Apply a soap solution to the exhaust port.
- Check the exhaust port for leakage. Slight leakage is permissible.
- If leakage is excessive.
- Replace the valve. Refer to
Instrument Panel Mounted Air Brake Park Control Valve Replacement
.
- Push in the system park knob .
- Remove the wheel blocks.