Air Compressor Replacement RPO LG4, LF8

Tools Required

J 42971 Quick Disconnect Tool

1. Apply the parking brake.
2. Block the wheels.
3. Drain all of the air reservoirs. Refer to Air Brake Reservoir Draining .
4. Drain the engine coolant to below the level of the air compressor. Refer to Cooling System Draining and Filling .
5. Remove the air compressor discharge pipe at the air compressor, using a J 42971 .
6. Remove the power steering pump. Refer to Power Steering Pump Replacement .
7. Remove the air compressor water inlet hose at the air compressor using a J 42971 .
8. Remove the air compressor water outlet hose at the air compressor using a J 42971 .
9. Remove the air compressor oil inlet hose at the air compressor.
10. Remove the air compressor oil outlet hose at the air compressor.



11. Remove the air compressor using the following procedure:

11.1.

Support the air compressor.

11.2.

Remove the air compressor bolts.

11.3.

Remove the air compressor.

12. Clean the exterior of the air compressor with the engine degreaser GM P/N 1050436 (Canadian P/N 992878) or the equivalent.
13. Dry the air compressor immediately with compressed air.
14. Inspect all of the hoses for damage or leaking. Replace the hoses, if damaged or leaking.
15. Inspect the air compressor for cracks or damage. Replace the air compressor, if needed.

1. Install the air compressor.
2. Install the air compressor oil outlet hose at the air compressor.
3. Install the air compressor oil inlet hose at the air compressor.
4. Install the air compressor water outlet hose at the air compressor.
5. Install the air compressor water inlet hose at the air compressor.
6. Install the air compressor discharge front pipe at the air compressor.
7. Fill the engine cooling system. Refer to Cooling System Draining and Filling .
8. Fill the engine oil as needed.
9. Inspect for air leaks. Refer to Air Brake System Testing .
10. Inspect for the proper brake operation.
11. Remove the wheel blocks.