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.


    Object Number: 891317  Size: SH
  1. Ensure that the park brake lever is in the fully released position.
  2. Release the park brake lever boot from the floor console by applying light pressure inward on the sides of the boot retainer.
  3. Pull the boot away from the console to expose the front park brake cable adjusting nut (1).
  4. Release the tension from the park brake cable system at the front cable adjusting nut (1).
  5. Using ONLY HAND TOOLS, loosen the adjusting nut (1) completely to the end of the front cable threaded rod.


    Object Number: 891757  Size: SH
  6. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  7. Remove the rear tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
  8. Remove the brake drums. Refer to Brake Drum Replacement .
  9. Position the J 21177-A to widest point of the brake drum inside diameter.
  10. Firmly hand tighten the set screw on the J 21177-A .

  11. Object Number: 891758  Size: SH
  12. Remove the J 21177-A from the brake drum and position it over the corresponding brake shoe assembly at its widest point.
  13. While holding the J 21177-A in position, insert a 0.635 mm (0.025 in) feeler gage between one side of the J 21177-A , and the corresponding brake shoe lining.
  14. Rotate the brake shoe adjuster screw until the brake shoe linings contact the J 21177-A , and the feeler gage.
  15. Specification
    Brake shoe lining-to-drum clearance: 0.635 mm (0.025 in).

  16. Repeat the above steps for the opposite brake drum and brake shoe assembly.
  17. Install the brake drums. Refer to Brake Drum Replacement .
  18. Adjust the park brake. Refer to Park Brake Adjustment .
  19. Install the rear tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
  20. Lower the vehicle.
  21. Position the park brake lever boot to the floor console and press the boot retainer into place to secure.