Drain the water and contaminants from the primary air brake supply reservoir daily . Daily draining is not necessary on reservoirs with the optional primary air brake supply reservoir drain valve, automatic type. The reservoir drain valve, automatic type, automatically drains water and contaminants.

1. Start the engine and charge the system with air.



2. Pull the cable which is attached to the reservoir drain valve, manual type, on the bottom of the supply reservoir.
3. After the water and contaminants stop draining, release the cable and the reservoir drain valve, manual type, will close.

1. Block the vehicle wheels.
2. Apply the parking brake.



3. Drain the supply reservoir.

On reservoirs with a reservoir drain valve, manual type, pull the reservoir drain valve cable until the reservoir drain valve opens.

4. Continue to hold the reservoir drain valve cable until all the air has drained from the reservoir.



5. Drain the supply reservoir.

On reservoirs with a reservoir drain valve, automatic type, push upward on the wire in the exhaust port of the reservoir drain valve, automatic type, and hold until all the air is drained.

6. Open the reservoir drain valve, manual type, and drain the front service reservoir.
7. Open the reservoir drain valve, manual type, and drain the rear service reservoirs. There is often more than 1 rear service reservoir. Ensure that all of the rear service reservoirs are drained.