For 1990-2009 cars only
- Set the parking brake.
- Drain the air reservoirs. Refer to Draining Reservoirs .
- Start the engine. Charge the air system to the governor cut-out point.
- Verify that an exhaust of air occurs at the air dryer exhaust port. This is the air dryer purge cycle.
- If the air dryer does not cycle properly, check the system for leaks at the air line connections and in the air brake system. Replace the air dryer if necessary.
