GM Service Manual Online
For 1990-2009 cars only

Power Brake Booster Replacement Commercial

Bleeding the Hydraulic Booster System

Notice: Power steering fluid and brake fluid cannot be mixed. If brake seals contact power steering fluid or steering seals contact brake fluid, seal damage will result.

Bleed the hydraulic booster system any time you open the system. Refer to Power Steering System Bleeding in Power Steering System.

Flushing the Hydraulic Booster System

Refer to Power Steering System Flushing in Power Steering System.

Hydraulic Booster System Pipes, Hoses, and Fittings

Refer to Power Steering Hoses Replacement .

Power Steering Pump Service

Refer to Power Steering Pump Replacement in Power Steering System.

Removal Procedure


    Object Number: 173646  Size: SH
  1. Apply the parking brake.
  2. Disconnect the hoses from the booster assembly.
  3. Remove the master cylinder mounting nuts.
  4. Remove the master cylinder.
  5. Support the master cylinder.


    Object Number: 172143  Size: SH
  6. Remove the pushrod retainer.
  7. Remove the retaining clip.

  8. Object Number: 172151  Size: SH
  9. Remove the washer.

  10. Object Number: 172156  Size: SH
  11. Remove the booster pushrod.

  12. Object Number: 173646  Size: SH
  13. Remove the booster mounting nuts.
  14. Remove the booster assembly.

Installation Procedure


    Object Number: 173646  Size: SH
  1. Install the booster assembly.
  2. 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 booster mounting nuts.
  4. Tighten
    Tighten the nuts to 36 N·m (27 lb ft).


    Object Number: 172156  Size: SH
  5. Install the booster pushrod.

  6. Object Number: 172151  Size: SH
  7. Install the washer.

  8. Object Number: 172143  Size: SH
  9. Install the retaining clip.
  10. Install the pushrod retainer.

  11. Object Number: 173646  Size: SH
  12. Install the master cylinder.
  13. Install the master cylinder mounting nuts.
  14. Tighten
    Tighten the nuts to 36 N·m (27 lb ft).

  15. Install the hoses.
  16. Tighten
    Tighten the hoses to 27 N·m (20 lb ft).

  17. Bleed the booster. Refer to Power Steering System Bleeding in Power Steering System.
  18. Release the parking brake.

Power Brake Booster Replacement Motorhome

Bleeding the Hydraulic Booster System

Notice: Power steering fluid and brake fluid cannot be mixed. If brake seals contact power steering fluid or steering seals contact brake fluid, seal damage will result.

Bleed the hydraulic booster system any time you open the system. Refer to Power Steering System Bleeding in Power Steering System.

Flushing the Hydraulic Booster System

Refer to Power Steering System Flushing in Power Steering System.

Hydraulic Booster System Pipes, Hoses, and Fittings

Refer to Power Steering Hoses Replacement in Power Steering System.

Power Steering Pump Service

Refer to Power Steering Pump Replacement in Power Steering System.

Removal Procedure


    Object Number: 172229  Size: SH
  1. Apply the parking brake.
  2. Disconnect the hoses from the booster assembly.
  3. Remove the master cylinder mounting nuts.
  4. Remove the master cylinder.
  5. Support the master cylinder.

  6. Remove the brake pedal rod.

  7. Object Number: 172232  Size: SH
  8. Remove the brake-booster-to-frame mounting nut.
  9. Remove the brake-booster-to-frame mounting bolt and washer.

  10. Object Number: 172235  Size: SH
  11. Remove the brake-booster-to-frame mounting nut.
  12. Remove the brake-booster-to-frame mounting bolt and washer.

  13. Object Number: 172237  Size: SH
  14. Remove the brake-booster-to-frame mounting nuts.
  15. Remove the brake-booster-to-frame mounting bolts and washers.
  16. Remove the booster assembly.

Installation Procedure

  1. Install the booster assembly.

  2. Object Number: 172237  Size: SH
  3. Install the brake-booster-to-frame mounting bolts and washers.
  4. 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.

  5. Install the brake-booster-to-frame mounting nuts.
  6. Tighten
    Leave the nuts finger tight.


    Object Number: 172235  Size: SH
  7. Install the brake-booster-to-frame mounting bolt and washer.
  8. Install the brake-booster-to-frame mounting nut.
  9. Tighten
    Leave the nut finger tight.


    Object Number: 172232  Size: SH
  10. Install the brake-booster-to-frame mounting bolt and washer.
  11. Important: Install the brake-booster-to-frame mounting bolt with the head on the inboard side of the vehicle.

  12. Install the brake-booster-to-frame mounting nut.
  13. Tighten
    Leave the nut finger tight and tighten all of the brake-booster-to-frame mounting nuts to 36 N·m (27 lb ft).

  14. Install the brake pedal rod.

  15. Object Number: 172229  Size: SH
  16. Install the master cylinder.
  17. Install the master cylinder mounting nuts.
  18. Tighten
    Tighten the master cylinder mounting nuts to 36 N·m (27 lb ft).

  19. Install the hoses.
  20. Tighten
    Tighten the hoses to 27 N·m (20 lb ft).

  21. Bleed the booster. Refer to Power Steering System Bleeding in Power Steering System.
  22. Release the parking brake.