For 1990-2009 cars only
- Block the wheels.
- Start the engine.
- Charge the system air pressure to the governor cut-out point.
- Release the brake pedal.
- Coat the exhaust port and the area around the exhaust port retaining ring with a soap solution.
- Check that the leakage is less than a 25 mm (1 in) bubble in 3 seconds.
- Replace or overhaul the valve (5) if the leakage exceeds these limitations. Rear Air Brake Relay Valve Replacement or Air Brake System Description and Operation .
- Firmly apply the brake pedal.
- Coat the exhaust port with a soap solution.
- Check that leakage is less than a 25 mm (1 in) bubble in 3 seconds.
- Coat the outside of the valve where the cover joins the body with a soap solution.
- Leakage is not permissible.
- Replace or overhaul the valve (5) if any bubbles appear. Rear Air Brake Relay Valve Replacement or Air Brake System Description and Operation .
- Remove the wheel blocks.
