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 Brake Fluid Effects on Paint and Electrical Components Caution.

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.

Checking and Adding Fluid

For information on checking and adding fluid to the power brake booster system, refer to Checking and Adding Power Steering Fluid Power Steering.

Bleeding the Power Brake Booster System

For information on bleeding the power brake booster system, refer to Power Steering System Bleeding Service and Repair.

Flushing the Power Brake Booster System

For information on flushing the power brake booster system, refer to Power Steering System Flushing Power Steering System Flushing.

Removal Procedure

1. Apply the park brake and block the wheels.

2. Without disconnecting the brake pipes, remove the master cylinder and support with heavy mechanics wire or equivalent. Refer to Master Cylinder Replacement Removal and Replacement.




3. Disconnect the power brake booster inlet hose fitting (1).

4. Inspect the O-ring seal for damage and replace, if necessary.




5. Disconnect the power brake booster outlet hose fitting (1).

6. Inspect the O-ring seal for damage and replace, if necessary.




7. Remove the power brake booster pushrod retaining clip bolt (1).




8. Remove the power brake booster pushrod retaining clip (1).

9. Disconnect the power brake booster pushrod.




10. Remove the power brake booster nuts (1).

11. Remove the power brake booster.

12. Remove the power brake booster gasket.

13. Inspect the power brake booster gasket for damage and replace, if necessary.

Installation Procedure




1. Install the power brake booster gasket.

2. Install the power brake booster.

Caution: Refer to Fastener Caution Fastener Caution.

3. Install the power brake booster nuts (1) and tighten to 36 Nm (27 lb ft).

4. Apply a thin coat of high temperature lubricant, GM P/N 12345994 (Canadian P/N 10953501) to the power brake booster pushrod pivot pin.

5. Connect the power brake booster pushrod.




6. Install the power brake booster pushrod retaining clip (1).

7. Rotate the power brake booster retaining clip 360 degrees to ensure the clip is fully engaged in the brake pedal pivot pin groove.




8. Install the power brake booster pushrod retaining clip bolt (1) and tighten to 10 Nm (89 lb in).





Note: Ensure the O-ring seals are properly positioned on the power brake booster inlet and outlet hose fittings.

9. Connect the power brake booster outlet hose fitting (1) and tighten the fitting to 33 Nm (24 lb ft).




10. Connect the power brake booster inlet hose fitting (1) and tighten the fitting to 33 Nm (24 lb ft).

11. Install the master cylinder. Refer to Master Cylinder Replacement Removal and Replacement.

12. Bleed the power steering system. Refer to Power Steering System Bleeding Service and Repair.

13. Calibrate the brake pedal position sensor. Refer to Brake Pedal Position Sensor Calibration Brake Pedal Position Sensor Calibration.