GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 21177-A Drum to Brake Shoe Clearance Gauge

Important: Park brake adjustment is not necessary after replacing the park brake lever or park brake cables. The park brake cables are tensioned automatically by cycling the park brake lever three times.

  1. Apply and fully release the parking brake three times.
  2. Verify that the parking brake lever releases completely.
  3. Turn ON the ignition. Verify that the red BRAKE warning indicator lamp is off.
  4. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  5. Remove the rear tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.

  6. Object Number: 177186  Size: SH

    Important: Do not operate the park brake lever with the rear disc brake rotor(s) removed.

  7. Remove the rear disc brake rotors. Refer to Rear Brake Rotor Replacement in Disc Brakes.

  8. Object Number: 177200  Size: SH
  9. Place the inside measurement contacts of theJ 21177-A at the widest point of the drum portion of the brake rotor.
  10. Tighten the set screw on the tool in order to ensure the proper measurement when removing the tool from the drum.

  11. Object Number: 177201  Size: SH
  12. Position the outside measurement contacts of the J 21177-A over the park brake shoe at the widest point.
  13. Important: If the gap between the adjuster nut and the adjuster screw exceeds 5 mm (0.25 in) during the adjustment procedure, the park brake shoe must be replaced.

  14. Adjust the park brake shoe-to-drum clearance by rotating the adjustment nut on the park brake actuator.
  15. Specification
    0.38 mm (0.015 in)

  16. Install the rear brake rotors. Refer to Rear Brake Rotor Replacement in Disc Brakes.
  17. Install the rear tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  18. Apply and release the park brake lever three times .
  19. Apply the park brake lever. Inspect the rotation of the rear wheels:
  20. • The wheels should not rotate forward.
    • The wheels should drag or not rotate rearward.
  21. If the rear tire and wheel assemblies rotate forward or do not exhibit drag rearward, repeat the adjustment procedure.
  22. Release the parking lever. Verify that the wheels rotate freely
  23. Lower the vehicle