For 1990-2009 cars

1. Apply the parking brake.
2. Block the wheels.
3. Run the engine in order to fully charge all service reservoirs.
4. Turn off the engine.
5. Drain the air pressure from the supply reservoir. Refer to Draining Reservoirs .
6. Disconnect the air line on the supply side of the valve (10).
7. Apply a soap solution to the open supply port of the valve (10).
8. Verify that leakage is less than a 25 mm (1 in) bubble in 5 seconds.
9. If the leakage exceeds this amount, drain the air pressure from all reservoirs and replace the valve (10). Refer to Reservoir Check Valve Replacement or overhaul the valve. Refer to Air Brake System Description and Operation .
10. Connect the supply port air line.
11. Start the engine.
12. Charge the air system to the governor cut-out point.
13. Connect the supply port air line.
14. Check the brake operation.
15. Remove the wheel blocks.