For 1990-2009 cars only
- Set the vehicle parking brake.
- Drain all of the air reservoirs. Refer to Draining Reservoirs .
- Start the engine.
- Charge the air system to the governor cut-out point.
- Verify that a discharge of air occurs at the air dryer exhaust port. This is the air dryer purge cycle.
If the air dryer does not cycle properly, inspect the air dryer system for leaks. Refer to Air Brake System Schematics. Overhaul or replace the air dryer as necessary.
