GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 21177-A Drum to Brake Shoe Clearance Gauge

Caution: Refer to Brake Dust Caution in the Preface section.

Important: The rear brakes must be adjusted manually after replacing the rear brake shoes.

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  2. Remove the brake drum. Refer to Brake Drum Replacement .

  3. Object Number: 750555  Size: SH
  4. Using the J 21177-A measure the inside diameter of the brake drum.

  5. Object Number: 750553  Size: SH

    Important: When performing the following service procedure, ensure that the J 21177-A is level before taking the measurement.

  6. Using the J 21177-A , adjust the brakes shoes until there is approximately 0.50 mm (0.020 in) clearance between the rear brake shoes and the rear brake drum.

  7. Object Number: 221  Size: SH
  8. Using a punch and hammer, remove and discard the knockout plug in the backing plate (1) which is directly behind the star wheel adjuster.
  9. Install the brake drum.

  10. Object Number: 794054  Size: SH
  11. Insert a flat bladed screw driver (1) and move the adjuster lever away from the star wheel.
  12. Using a brake adjusting tool, rotate the brake adjuster (2) until the amount of drag is equal on the left and right rear brake drums.
  13. Apply the brake pedal two times in order to center the brake shoes on the locating pins.
  14. Check the drums again for light drag. Adjust as necessary.
  15. Install an adjusting hole cover in the backing plate.
  16. Lower the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  17. Check the park brake adjustment. Refer to Park Brake Adjustment in Park Brake.