1. Install a test gauge in the air compressor discharge line.
2. Start the engine and build up air pressure.
3. Check the reading on the test gauge when the air compressor cuts out.

Compare the reading with the governor cut-out specification. Refer to Air Compressor Governor Valve Specifications .

4. Slowly reduce the air pressure in the system.

This is done by applying and releasing the brakes while the engine is running.

5. Check the reading on the test gauge when the air compressor cuts in.

Compare the reading with the governor cut-in specification. Refer to Air Compressor Governor Valve Specifications .

6. Adjust the governor if the cut-in or cut-out pressures are not within the specifications. Refer to Air Compressor Governor Valve Specifications .

Run leakage tests on the Bendix® D-2 governor in both the cut-in and the cut-out positions.

Apply a soap solution around the cover and the exhaust port. A slight bubble leakage is permitted. Excessive leakage indicates a faulty exhaust valve seat, exhaust stem O-ring, or O-ring at the top of the piston.

Apply a soap solution around the cover and to the exhaust port. A slight bubble leakage is permitted. Excessive leakage indicates a faulty exhaust valve seat, exhaust stem O-ring, or O-ring at the top of the piston.

If the governor does not function as described or if the leakage is excessive, overhaul or replace the governor. Refer to Air Compressor Governor Valve Replacement .