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 control.
6. Check that the parking brake chambers release promptly.
7. Have an assistant pull out on the system park control and release the brake pedal.
8. Check that a prompt exhaust of air occurs at the exhaust port.
9. Check that the parking brake chambers are applied by the position of the slack adjusters.
10. Apply the brake pedal hard.
11. Check the position of the spring brake chamber assembly pushrod. The pushrod should extend as you apply the brake pedal.
12. Remove the wheel blocks.