GM Service Manual Online
For 1990-2009 cars only

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice in the Preface section.

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. Refer to General Information to select the correct fluid.

Checking and Adding Fluid

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

Bleeding the Hydraulic Booster System

Refer to Power Steering System Bleeding .

Flushing the Hydraulic Booster System

Refer to Power Steering System Flushing .

Removal Procedure


    Object Number: 793140  Size: SH
  1. Apply the park brake and block the wheels.
  2. Disconnect the inlet hose, the steering gear hose, and the return hoses from the booster assembly.
  3. Remove the master cylinder retaining nuts and remove the master cylinder. Do not disconnect the brake pipes. .
  4. Remove the stop lamp switch retaining clip (4) from the brake pedal pin (1).
  5. Remove the stop lamp switch (2) and the pushrod (3) from the brake pedal pin (1).

  6. Object Number: 361376  Size: SH
  7. Remove the booster to bulkhead nuts.
  8. Remove the booster assembly.
  9. Remove the gasket.

Installation Procedure


    Object Number: 361376  Size: SH
  1. Install the gasket.
  2. Install the booster assembly.
  3. 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.

  4. Install the booster to bulkhead nuts.
  5. Tighten
    Tighten the nuts to 36 N·m (27 lb ft).


    Object Number: 793140  Size: SH
  6. Install the stop lamp switch (2) and the pushrod (3) to the brake pedal pin (1).
  7. Install the stop lamp switch retaining clip (4) to the brake pedal pin (1).
  8. Install the master cylinder and the master cylinder retaining nuts.
  9. Tighten
    Tighten the nuts to 36 N·m (27 lb ft).

  10. Connect the return hose, the steering gear hose, and the inlet hoses.
  11. Bleed the hydraulic booster system. Refer to Power Steering System Bleeding .
  12. Release the park brake and unblock the wheels.