For 1990-2009 cars only
- Block the wheels.
- Start the engine.
- Charge the system air pressure to the governor cut-out point.
- Pull out the trailer air supply knob.
- Pull out the system park knob.
- Apply a soap solution to the exhaust vent and around the base of the trailer air supply knob.
- Verify that leakage is less than a 25 mm (1 in) bubble in 5 seconds. If not, replace the valve.
- If the leakage exceeds these limitations, replace the valve.
- Push in the trailer air supply knob.
- Apply a soap solution to the exhaust port.
- Check that the leakage is less than a 25 mm (1 in) bubble in 5 seconds.
- If the leakage exceeds these limitations, replace the valve.
- Set the parking brake.
- Remove the wheel blocks.
