Hydraulic Brake Booster: Service and Repair

Power Brake Booster Replacement

Warning: Refer to Brake Fluid Irritant Warning (Brake Fluid Irritant Warning).


Caution: Refer to Brake Fluid Effects on Paint and Electrical Components Caution (Vehicle Damage Warnings).

Caution: Hydraulic brake systems use two distinct and incompatible fluids. Power steering fluid is used in the hydraulic brake booster system. Brake fluid is used in the master cylinder and brake pipes. Use extreme care when selecting brake system fluids, or seal damage can result. Refer to General Information to select the correct fluid.

Removal Procedure

Warning: Refer to Battery Disconnect Warning (Service Precautions).

1. Disconnect the battery negative cable.
2. Place the vehicle on a level surface.
3. Block the front wheels.
4. Apply the parking brake.
5. Disconnect the power steering inlet hose. Refer to Power Steering Return Hose Replacement (Power Steering Return Hose Replacement).
6. Disconnect the power steering pressure hose. Refer to Power Steering Pressure Pipe/Hose Replacement (Power Steering Pressure Pipe/Hose Replacement).
7. Disconnect the power steering gear to booster hose. Refer to Power Steering Pressure Pipe/Hose Replacement (Power Steering Pressure Pipe/Hose Replacement).




8. Remove the master cylinder. Refer to Master Cylinder Replacement (Removal and Replacement).




9. Remove the wiring harness bracket (2).
10. Remove the spacer (3) from the booster assembly (4).
11. Remove the left closeout insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side (Instrument Panel Insulator Panel Replacement - Left Side).
12. Remove the left knee bolster. Refer to Driver Knee Bolster Replacement (Driver Knee Bolster Replacement).




13. Remove the vacuum brake booster retainer clip (2) from the brake pedal clevis pin.
14. Remove the foam spacer (3) from the brake pedal clevis pin.
15. Disconnect the vacuum brake booster push rod from the brake pedal clevis pin.




16. Remove the vacuum brake booster mounting nuts (1) from the brake pedal assembly.
17. Remove the vacuum brake booster assembly.
18. Remove the vacuum brake booster mounting gasket, if gasket replacement is necessary.

Installation Procedure




1. Install the vacuum brake booster mounting gasket to the booster, if removed previously.
2. Install the vacuum brake booster assembly to the vehicle.





Caution: Refer to Fastener Caution (Fastener Caution).

3. Install the brake pedal assembly to booster stud mounting nuts (1).

Tighten the brake pedal assembly to booster stud mounting nuts to 36 Nm (27 lb ft).

4. Apply a small amount of lubricant, GM P/N 12346293 or equivalent to the clevis pin of the brake pedal.




5. Connect the vacuum brake booster pushrod to the brake pedal assembly pedal clevis pin.
6. Install the foam spacer (3) to the brake pedal assembly clevis pin.
7. Install the retaining clip (2) to the brake pedal assembly clevis pin.
8. Install the left knee bolster. Refer to Driver Knee Bolster Replacement (Driver Knee Bolster Replacement).
9. Install the left closeout insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side (Instrument Panel Insulator Panel Replacement - Left Side).




10. Install the booster spacer (3).
11. Install the wiring harness bracket (2).
12. Install the master cylinder (1) to the booster assembly (4). Refer to Master Cylinder Replacement (Removal and Replacement).
13. Connect the power steering pressure hose. Refer to Power Steering Pressure Pipe/Hose Replacement (Power Steering Pressure Pipe/Hose Replacement).
14. Connect the power steering gear to booster hose. Refer to Power Steering Pressure Pipe/Hose Replacement (Power Steering Pressure Pipe/Hose Replacement).
15. Connect the power steering inlet hose. Refer to Power Steering Return Hose Replacement (Power Steering Return Hose Replacement).
16. Connect the negative battery cable.
17. Bleed the hydraulic booster system. Refer to Power Steering System Bleeding (Service and Repair).
18. Recalibrate the brake position sensor. Refer to Brake Pedal Position Sensor Calibration ().
19. Remove the blocks from the front wheels.
20. Release the park brake.