For 1990-2009 cars

1. Block the wheels.
2. Disconnect the air line from the balance port (4).
3. Start the engine.
4. Charge the system air pressure to the governor cut-out point.
5. Apply the system park valve.
6. Apply a soap solution to the exhaust port and the balance port (4).
7. Check that the leakage is less than a 25 mm (1 in) bubble in 5 seconds. Replace or overhaul the valve if the leakage exceeds these limitations. Refer to Rear Air Brake Quick Release Double Check Valve Replacement - Right Side or Air Brake System Description and Operation .
8. Apply a soap solution around the cap nut at the supply port (6) and the seam between the upper and the lower bodies.
9. Leakage is not permissible. Replace or overhaul the valve if bubbles appear. Refer to Rear Air Brake Quick Release Double Check Valve Replacement - Right Side or Air Brake System Description and Operation .
10. Pull out the system park valve.
11. Connect the line at the balance port (4).
12. Disconnect the line at the supply port (6).
13. Firmly apply the brake pedal.
14. Apply a soap solution to the supply port (6).
15. Check that leakage is less than 25 mm (1 in) bubble in 5 seconds.
16. Replace or overhaul the valve if the leakage exceeds these limitations. Refer to Rear Air Brake Quick Release Double Check Valve Replacement - Right Side or Air Brake System Description and Operation .
17. Connect the air line at the supply port (6).
18. Check for leaks in the air lines.
19. Remove the wheel blocks.