For 1990-2009 cars

1. Block the wheels.
2. Start the engine.
3. Charge the system air pressure to the governor cut-out point.
4. Release the brake pedal.
5. Apply the system park valve.
6. Verify the spring brake chambers release promptly.
7. Pull out on the system park valve.
8. Release the brake pedal.
9. Check that there is a prompt exhaust of air at the valve exhaust port.
10. Check the slack adjuster position to ensure that the spring brake is applied.
11. Apply the brake pedal.
12. Check the position of the spring brake chamber assembly pushrod. The pushrod should extend as you apply the brake pedal.
13. Remove the wheel blocks.