Hydraulic Brake Booster: Service and Repair

Hydraulic Brake Booster Replacement

Caution:

Notice:

Notice: 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.

Removal Procedure

Caution: Refer to Battery Disconnect in 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.
6. Disconnect the power steering pressure hose.
7. Disconnect the power steering gear to booster hose.





8. Remove the master cylinder.





9. Remove the wiring harness bracket (2).
10. Remove the spacer (3) from the booster assembly (4).
11. Remove the left closeout insulator panel.
12. Remove the left knee bolster.





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.





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

3. Tighten the brake pedal assembly to booster stud mounting nuts to 36 Nm (27 ft. lbs.).
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.
9. Install the left closeout insulator panel.





10. Install the booster spacer (3).
11. Install the wiring harness bracket (2).
12. Install the master cylinder (1) to the booster assembly (4).
13. Connect the power steering pressure hose.
14. Connect the power steering gear to booster hose.
15. Connect the power steering inlet hose.
16. Connect the negative battery cable.
17. Bleed the hydraulic booster system.
18. Recalibrate the brake position sensor.
19. Remove the blocks from the front wheels.
20. Release the park brake.