Tools Required

J 21177-A Drum to Brake Shoe Clearance Gage

1. Release the park brake.
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
3. Remove the tire and wheel.

•	For vehicles with steel wheels, refer to Tire and Wheel Removal and Installation in Tires and Wheels.

•	For Chevrolet and Oldsmobile vehicles with aluminum wheels, refer to Tire and Wheel Removal and Installation in Tires and Wheels.

•	For Pontiac and Export vehicles with aluminum wheels, refer to Tire and Wheel Removal and Installation in Tires and Wheels.

4. Remove the brake drum. Refer to Brake Drum Replacement .
5. Ensure that the stops on both of the park brake lever is against the brake shoe edges. If the parking brake cable is holding the stops off the edge of the brake shoe, adjust the park brake cable. Refer to Park Brake Cable Service/Adjustment .



6. Use the J 21177-A in order to measure the drum inside diameter.



7. Rotate the adjuster wheel and use the J 21177-A in order to adjust the brake shoe diameter to 1.27 mm (0.05 in) less than the drum inside diameter measurement.
8. Install the brake drum. Refer to Brake Drum Replacement .
9. Apply and release the brake pedal 30-35 times with a one second pause between each brake application.
10. Install the tire and wheel.

•	For vehicles with steel wheels, refer to Tire and Wheel Removal and Installation in Tires and Wheels.

•	For Chevrolet and Oldsmobile vehicles with aluminum wheels, refer to Tire and Wheel Removal and Installation in Tires and Wheels.

•	For Pontiac and Export vehicles with aluminum wheels, refer to Tire and Wheel Removal and Installation in Tires and Wheels.

11. Lower the vehicle.