GM Service Manual Online
For 1990-2009 cars only

Power Vacuum Brake Booster Replacement 4.6L V-8

Removal Procedure


    Object Number: 491257  Size: SH
  1. Place the vehicle on a flat surface.
  2. Block the front wheels.
  3. Apply the parking brake.
  4. To allow access for the removal of the vacuum brake booster, position the gearshift lever into the lowest gear.
  5. Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement .
  6. Disconnect the fuel vapor lines in front of the brake booster.
  7. • For the lines that have the plastic connectors, refer to Plastic Collar Quick Connect Fitting Service .
    • For the lines that have the metal connectors, refer to Metal Collar Quick Connect Fitting Service .

    Object Number: 177410  Size: SH
  8. Remove the master cylinder mounting nuts (3).
  9. Important: In the following service step, the master cylinder does not have to be removed. Move the master cylinder forward just enough to clear the studs on the vacuum brake booster. This will flex the brake pipes slightly. Do not bend or distort the pipes.

  10. Disconnect the master cylinder (1) from the brake booster (2).
  11. Disconnect the shift control cable from the shaft lever pin and position it out of the way. Refer to Automatic Transmission Range Selector Cable Replacement - Console .

  12. Object Number: 491255  Size: SH
  13. Disconnect the vacuum check valve (2) from the vacuum booster.
  14. Remove the left closeout insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side .
  15. Remove the left knee bolster. Refer to Driver Knee Bolster Replacement .
  16. To access the left lower brake pedal to vacuum brake booster mounting nut, remove the steering column mounting nuts. Refer to Steering Column Replacement .
  17. Lower the steering column and secure it.

  18. Object Number: 1678341  Size: SH
  19. Remove the vacuum brake booster pushrod retaining clip (2) from the brake pedal clevis pin.
  20. Remove the foam spacer (3) from the brake pedal clevis pin.
  21. Disconnect the brake booster pushrod from the brake pedal clevis pin.

  22. Object Number: 1678358  Size: SH
  23. Remove the vacuum brake booster mounting nuts (1) from the brake pedal assembly.
  24. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .

  25. Object Number: 333761  Size: SH
  26. Support the front frame with jack stands.
  27. Loosen the left side bolts from the frame to the body. Refer to Front Frame Replacement .
  28. Lower the left side frame 2-3 inches to gain enough clearance to remove the brake booster. Refer to Front Frame Replacement .

  29. Object Number: 106322  Size: SH
  30. Remove the vacuum brake booster from the vehicle.
  31. Important: The gasket does not have to be replaced every time the booster is removed. Replace the gasket only if necessary.

  32. Remove the vacuum brake booster mounting gasket.

Installation Procedure


    Object Number: 106322  Size: SH
  1. Install the vacuum brake booster mounting gasket to the booster, if removed previously.
  2. Install the vacuum brake booster to the vehicle.
  3. Lower the vehicle onto the engine frame. Refer to Front Frame Replacement .
  4. Remove the jack stands.
  5. Lower the vehicle.
  6. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1678358  Size: SH
  7. Install the brake pedal assembly to booster stud mounting nuts (1) to the booster studs.
  8. Tighten
    Tighten the brake pedal assembly to booster stud mounting nuts to 30 N·m (22 lb ft).


    Object Number: 1678341  Size: SH
  9. Apply a small amount of lubricant, GM P/N 12346293 or equivalent to the clevis pin of the brake pedal.
  10. Connect the vacuum brake booster pushrod to the brake pedal clevis pin.
  11. Install the foam spacer (3) to the brake pedal clevis pin.
  12. Install the retainer clip (2) to the brake pedal assembly clevis pin.
  13. Install the steering column.
  14. Install the steering column mounting attaching nuts. Refer to Steering Column Replacement .
  15. Install the left knee bolster. Refer to Driver Knee Bolster Replacement .
  16. Install the left closeout insulator panel. Refer to Instrument Panel Insulator Panel Replacement - Left Side .

  17. Object Number: 491324  Size: SH
  18. Install the shift control cable to the shift cable bracket. Refer to Automatic Transmission Range Selector Cable Replacement - Console .
  19. Position the gearshift lever into park.

  20. Object Number: 491255  Size: SH
  21. Install the brake booster vacuum check valve (2) to the vacuum brake booster.
  22. Install the master cylinder to the vacuum brake booster. Refer to Master Cylinder Replacement .
  23. Connect the fuel vapor lines in front of the brake booster.
  24. • For the lines that have the plastic connectors, refer to Plastic Collar Quick Connect Fitting Service .
    • For the lines that have the metal connectors, refer to Metal Collar Quick Connect Fitting Service .
  25. Remove the blocks from the front wheels.
  26. Release the parking brake.

Power Vacuum Brake Booster Replacement 3.8L V-6

Removal Procedure


    Object Number: 707318  Size: SH
  1. Remove the fuel injector sight shield. Refer to Intake Manifold Cover Replacement .
  2. Disconnect the electrical connector from the exhaust gas recirculation (EGR) valve (1).
  3. Disconnect the engine harness clips (3).
  4. Position the harness to the side.

  5. Object Number: 675866  Size: SH
  6. Disconnect the brake fluid level sensor (1).

  7. Object Number: 420706  Size: SH
  8. Remove the master cylinder mounting bolts.
  9. Remove the master cylinder. Position the master cylinder to the side.

  10. Object Number: 491255  Size: SH
  11. Disconnect the vacuum brake booster check valve and hose (2).
  12. Remove the left knee bolster. Refer to Driver Knee Bolster Replacement .
  13. Remove the steering column support mounting bolts. Refer to Steering Column Replacement .
  14. Lower the steering column and support with mechanic's wire.
  15. Disconnect the brake pedal position sensor (BBPS) electrical connector. Refer to Brake Pedal Position Sensor Replacement .

  16. Object Number: 1678341  Size: SH
  17. Remove the vacuum brake booster pushrod retainer clip (2).
  18. Remove the vacuum brake booster pushrod spacer (3).

  19. Object Number: 1678358  Size: SH
  20. Remove the mounting nuts (1) for the steering column.

  21. Object Number: 106322  Size: SH
  22. Remove the vacuum brake booster.
  23. Important: If the gasket is damaged, replace it. DO NOT reuse it, replace with new.

  24. Remove the vacuum brake booster gasket.

Installation Procedure


    Object Number: 106322  Size: SH
  1. Install the vacuum brake booster gasket.
  2. Install the vacuum brake booster.

  3. Object Number: 1678341  Size: SH
  4. Install the pushrod to the brake pedal.
  5. Install the spacer (3).
  6. Install the retaining clip (2).
  7. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1678358  Size: SH
  8. Install the mounting nuts (1).
  9. Tighten
    Tighten the nuts to 30 N·m (22 lb ft).

  10. Connect the BPPS electrical connector to the BAS sensor. Refer to Brake Pedal Position Sensor Replacement .

  11. Object Number: 420706  Size: SH
  12. Install the master cylinder. Refer to Master Cylinder Replacement .
  13. Position the steering column.
  14. Install the steering column. Refer to Steering Column Replacement .
  15. Install the knee bolster panel. Refer to Driver Knee Bolster Replacement .

  16. Object Number: 491255  Size: SH
  17. Install the vacuum brake booster check valve and hose (2).

  18. Object Number: 675866  Size: SH
  19. Install the brake fluid level sensor electrical connector (1).

  20. Object Number: 707318  Size: SH
  21. Position the engine wiring harness (2).
  22. Connect the electrical connector for the EGR valve (1).
  23. Connect the engine harness clips (3).
  24. Install the fuel injector sight shield. Refer to Intake Manifold Cover Replacement .