GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 21177-A Drum to Brake Shoe Clearance Gage

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

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


    Object Number: 1505818  Size: SH
  1. Remove the rear tire and wheel. Refer to Tire and Wheel Removal and Installation .
  2. Remove the rear brake drum retainer, if necessary.
  3. Loosen the adjuster nut for the park brakes.
  4. Important: Before removing the brake drum, apply a small amount of penetrating oil around the wheel studs, axle shaft hub and brake drum.

  5. Remove the rear brake drum.

  6. Object Number: 1241711  Size: SH
  7. Using the J 21177-A (1), measure the inside diameter of the brake drum.

  8. Object Number: 1505825  Size: SH

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

  9. Using the J 21177-A (1) , adjust the brakes shoes until there is approximately 0.76 mm (0.030 in) clearance between the rear brake shoes and the rear brake drum.

  10. Object Number: 1505818  Size: SH
  11. Install the brake drum.
  12. With heavy force, apply the brake pedal 2 times in order to center and adjust the brake shoes.
  13. Inspect the drums again for light drag. If necessary, repeat the above steps for adjusting the brakes.
  14. Lower the vehicle. Refer to Lifting and Jacking the Vehicle .
  15. Adjust the park brake. Refer to Park Brake Adjustment .