For 1990-2009 cars

## Air Compressor Replacement LG5

### Removal Procedure

1. Apply the parking brake.
2. Block the wheels.
3. Drain all of the air reservoirs. Refer to Draining Reservoirs in Air Brakes.
4. Drain the engine coolant to below the level of the air compressor. Refer to Cooling System Draining and Filling in Engine Cooling.
5. Remove the air compressor discharge pipe clip nuts.
6. Remove the nut and the air compressor discharge pipe at the air compressor.
7. Remove the governor air line at the air compressor. Refer to Air Compressor Governor Valve Replacement .
8. Remove the air compressor air inlet hose.
9. Remove the air compressor water inlet hose at the air compressor.
10. Remove the air compressor water outlet hose at the air compressor.
11. Remove the air compressor oil inlet hose clip bolt at the air compressor.
12. Remove the air compressor oil inlet hose clip at the air compressor.
13. Remove the air compressor oil inlet hose at the air compressor.
14. Remove the power steering pump. Refer to Power Steering Pump Replacement in Power Steering System.
15. Remove the air compressor flange bolts and the washers.
16. Remove the air compressor bracket bolts and the washers.
17. Remove the air compressor.
18. Remove the gasket from the air compressor flange.
19. Clean the exterior of the air compressor with the engine degreaser GM P/N 1050436 or the equivalent.
20. Dry the air compressor immediately with compressed air.
21. Inspect the air compressor crankcase for cracks or damage.
22. Inspect the air compressor flange for cracks or damage.
23. Inspect the air compressor brackets for cracks or damage.
24. Inspect the air compressor oil inlet hose for damage or leaking. Replace the air compressor oil inlet hose if damaged or leaking.
25. Inspect the air compressor oil outlet hose for damage or leaking. Replace the air compressor oil outlet hose if damaged or leaking.
26. Inspect the air compressor water inlet hose for damage or leaking. Replace the air compressor water inlet hose if damaged or leaking.
27. Inspect the air compressor water outlet hose for damage or leaking. Replace the air compressor water outlet hose if damaged or leaking.

### Installation Procedure

1. Install the new gasket onto the air compressor flange.
2. Install the air compressor.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

3. Install the following components:

3.1. | The washers

3.2. | The air compressor flange bolts

Tighten
Tighten the air compressor flange bolts to 100 N·m (74 lb ft).

4. Install the washers and the air compressor bracket bolts.
5. Finger tighten the bracket bolts before torquing the bracket bolts to the specifications.

Tighten
Tighten the air compressor bracket bolts to 67 N·m (49 lb ft).

6. Install the power steering pump. Refer to Power Steering Pump Replacement in Power Steering System.
7. Install the air compressor oil inlet hose at the air compressor.

Tighten
Tighten the air compressor oil inlet hose nut to 13 N·m (115 lb in).

8. Install the air compressor oil inlet hose clip at the air compressor.
9. Install the air compressor oil inlet hose clip bolt at the air compressor.

Tighten
Tighten the air compressor oil inlet hose clip bolt to 67 N·m (49 lb ft).

10. Install the air compressor water outlet hose at the air compressor.

Tighten
Tighten the air compressor water outlet hose nut to 24 N·m (18 lb ft).

11. Install the air compressor water inlet hose at the air compressor.

Tighten
Tighten the air compressor water inlet hose nut to 24 N·m (18 lb ft).

12. Install the air compressor air inlet hose.

Tighten
Tighten the air compressor air inlet hose clamp to 2.75 N·m (22 lb in).

13. Install the governor air line at the air compressor.
14. Install the air compressor discharge pipe at the air compressor.
15. Install the air compressor discharge front pipe clip nuts at the air compressor.

Tighten
Tighten the air compressor discharge pipe clip nuts to 22 N·m (16 lb ft).

16. Install the air compressor discharge pipe nut at the air compressor.

Tighten
Tighten the air compressor discharge pipe nut to 22 N·m (16 lb ft).

17. Fill the engine cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
18. Fill the engine oil as needed.
19. Check for air leaks. Refer to Low Air Pressure Switch Operational Check in Air Brakes.
20. Check for the proper brake operation.
21. Remove the wheel blocks.

## Air Compressor Replacement LP4/L21

### Removal Procedure

1. Apply the parking brake.
2. Block the wheels.
3. Drain all of the air reservoirs. Refer to Draining Reservoirs in Air Brakes.
4. Drain the engine cooling system to below the level of the air compressor. Refer to Cooling System Draining and Filling in Engine Cooling.
5. Remove the air compressor discharge front pipe clip nuts.
6. Remove the nut and the air compressor discharge front pipe at the air compressor.
7. Remove the air compressor belt using the following steps:

7.1. | Loosen the air compressor bracket nut and the bolt.

7.2. | Remove the air compressor adjustment bracket nut, the washers, and the bolt.

7.3. | Pivot the air compressor in order to remove all air compressor belt tension.

7.4. | Lift the air compressor belt from the air compressor pulley.

8. Remove the governor air lines at the air compressor. Refer to Air Compressor Governor Valve Replacement .
9. Remove the air compressor water inlet hose at the air compressor.
10. Remove the air compressor water outlet hose at the air compressor.
11. Remove the air compressor oil inlet hose at the air compressor.
12. Remove the air compressor oil outlet hose at the air compressor.
13. Remove the air compressor bracket nuts and the washers.
14. Remove the air compressor using the following steps:

14.1. | Support the air compressor.

14.2. | Remove the air compressor bracket bolt and the washer.

14.3. | Lift the air compressor from the air compressor front bracket.

15. Clean the exterior of the air compressor using the engine degreaser GM P/N 1050436 or the equivalent.
16. Dry the air compressor immediately with compressed air.
17. Inspect the air compressor belt. Replace the air compressor belt as needed.
18. Inspect all of the brackets for wear or damage. Replace the brackets as needed.
19. Inspect the air compressor front bracket bushings for wear or damage. Replace the air compressor front bracket bushings as needed.
20. Inspect all of the hoses for leakage, wear or damage. Replace the hoses as needed.
21. Inspect the air compressor discharge pipe and the nut for wear or damage. Replace the air compressor discharge pipe and the nut as needed.
22. Inspect the air compressor pulley for wear or damage. Replace the air compressor pulley if wear or damage is detected.
23. Inspect the air compressor for cracks or damage. Overhaul or replace the air compressor as needed.

### Installation Procedure

1. Install the air compressor by loosely assembling the air compressor to the air compressor bracket with the air compressor bracket bolt, the washers, and the nut.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Install the air compressor oil outlet hose at the air compressor.

Tighten
Tighten the air compressor oil outlet hose clamp to 2.75 N·m (22 lb in).

3. Install the air compressor oil inlet hose at the air compressor.

Tighten
Tighten the air compressor inlet hose clamp to 2.75 N·m (22 lb in).

4. Install the air compressor water outlet hose at the air compressor.

Tighten
Tighten the air compressor water outlet hose clamp to 2.75 N·m (22 lb in).

5. Install the air compressor water inlet hose at the air compressor.

Tighten
Tighten the air compressor water inlet hose clamp to 2.75 N·m (22 lb in).

6. Install the governor air line at the air compressor.
7. Install the air compressor adjustment bracket bolt, the washers, and the nut.
8. Install the air compressor belt. Refer to Drive Belt Replacement in Engine Mechanical - 8.1L.
9. Install the air compressor discharge front pipe clip nuts at the air compressor.

Tighten
Tighten the air compressor discharge front pipe clip nuts to 22 N·m (16 lb ft).

10. Install the air compressor discharge front pipe at the air compressor.

Tighten
Tighten the air compressor discharge front pipe nut to 22 N·m (16 lb ft).

11. Fill the engine cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
12. Fill the engine oil as needed.
13. Inspect for air leaks. Refer to Air Brake System Testing in Air Brakes.
14. Inspect for the proper brake operation.
15. Remove the wheel blocks.