For 1990-2009 cars only
- Block the wheels.
- Disconnect the balance port air line.
- Start the engine.
- Charge the system air pressure to the governor cut-out point.
- Apply the system park control.
- Apply a soap solution to the exhaust port and the balance port (2).
- Check that leakage is less than a 25 mm (1 in) bubble in 3 seconds. Replace or overhaul the valve (3). Refer to Rear Air Brake Relay Double Check Valve Replacement or Air Brake System Description and Operation .
- Apply a soap solution around the cap nut at the control port (9) and at the seam between the cover and the valve body. Leakage is not permissible.
- Pull out the system park control.
- Connect the balance port (2) to the air line.
- Disconnect the control port (9) to the air line.
- Apply the brake pedal hard.
- Apply a soap solution to the control port, the exhaust port, and the area around the exhaust port retaining ring.
- Check that the leakage is less than a 25 mm (1 in) bubble in 3 seconds. Replace or overhaul the valve (3). Refer to Rear Air Brake Relay Double Check Valve Replacement or Air Brake System Description and Operation .
- Connect the control port air line.
- Check for leaks in the air lines.
- Remove the wheel blocks.
Notice: Do not apply the brake pedal while the balance port air line is disconnected. Damage to the slack adjuster can result.
