Parking Brake Adjustment

Special Tools 

CH-21177  Drum to Brake Shoe Clearance Gauge

For equivalent regional tools, refer to Special Tools .

1. Disable the parking brake cable adjuster. Refer to Parking Brake Cable Adjuster Disabling .
2. Turn the ignition to the OFF position.
3. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
4. Remove the rear tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
5. Remove the rear brake rotors. Refer to Rear Brake Rotor Replacement .
Fig 1: Measuring Inside Of Rotor
Courtesy of GENERAL MOTORS COMPANY
6. Set the CH-21177  Drum to Brake Shoe Clearance Gauge inside of the drum portion of the disc brake rotor at the widest point.
   • Place the contacts on the tool to the widest point of the park brake drum (1).
   • Tighten the set screw on the tool prior to removing the tool from the drum.
Fig 2: Adjusting Parking Brake Shoes Using Special Tool
Courtesy of GENERAL MOTORS COMPANY
7. Position the CH-21177  Drum to Brake Shoe Clearance Gauge over the parking brake shoes (1) at the widest point.
8. Turn the adjuster on the actuator until the park brake shoes just contact the CH-21177  Drum to Brake Shoe Clearance Gauge.
9. Repeat steps 6-8 for the opposite parking brake assembly.
10. Install the rear brake rotors. Refer to Rear Brake Rotor Replacement .
11. Install the rear tire and wheel assemblies. Refer to Tire and Wheel Removal and Installation .
12. Enable the parking brake cable adjuster. Refer to Parking Brake Cable Adjuster Enabling .
13. Apply the electronic parking brake.
14. Place the transmission in NEUTRAL.
15. Raise and support the vehicle so the tire and wheel assemblies are clear of the ground.
NOTE:

If the rear wheels rotate during the following test, repeat the adjustment procedure completely.

16. Attempt to rotate the rear tire and wheel assemblies.
    • The wheels should not rotate forward.
    • The wheels should not rotate rearward, or should exhibit significant rearward drag.
17. Release the electronic parking brake.
18. Verify the rear tire and wheel assemblies rotate freely and do not exhibit forward or rearward drag.
19. If the rear tire and wheel assemblies do not rotate freely and without forward or rearward drag, repeat the adjustment procedure completely.