GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 21177-A Drum to Brake Shoe Clearance Gage
    • J 28662 Brake Pedal Effort Gauge

    Important: The brake shoes will adjust by moderate brake pedal application. The vehicle does not have to be driven to adjust the brakes.


    Object Number: 179277  Size: SH
  1. Using the J 28662 depress the brakes three times with approximately 445 N·m (100 lbs) of force.
  2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Rotate the tire and wheel and check for brake drag.
  4. • The tire and wheel should turn freely
    • The drag should be heard more than felt
  5. If the brakes did not adjust properly remove the brake drums. Refer to Brake Drum Replacement .
  6. Hold the bottom of the brake shoe with the adjuster actuator.
  7. Move the top of the brake shoe in the brake apply direction.
  8. The adjuster actuator should rotate the star wheel.
  9. If the star wheel did not rotate replace or repair the adjuster. Refer to Brake Shoe Replacement .

  10. Object Number: 171482  Size: MH
  11. After brake shoe replacement use the following procedure to adjust the brake shoes.
  12. Use a J 21177-A in order to measure the drum inside diameter.
  13. Use a J 21177-A in order to measure the brake shoe diameter.
  14. Rotate the star wheel on the adjusting screw. Adjust the shoe and lining diameter to 1.27 mm (0.05 in) less than the inside diameter of the drum at each wheel.
  15. Install the brake drums. Refer to Brake Drum Replacement .