Checking and Adjusting the Air-Actuated Parking Brake Cable

sb mm 42.19.001

Check the air-actuated parking brake cable to ensure that the actuation system is in good working order, and for any adjustment that is needed.

  1. Park the vehicle on a level surface and chock the tires. 2.
  2. Make sure the air system is fully charged, then shut down the engine.
  3. Release the parking brake if it is applied.
  4. Remove the cotter pin and clevis pin from the clevis at the brake lever. See Fig..
  5. Pull the brake lever until shoe-to-drum contact is made.

    Fig. 1, Remove the Cotter Pin and Clevis Pin

  6. If adjustment is required, loosen the jam nut on the cable and adjust the clevis so that the pin hole in the clevis aligns with the hole in the lever.
  7. Install the clevis pin and a new cotter pin.
  8. Tighten the clevis jam nut to 80 lbf·in (904 N·cm). When properly adjusted, the cable should have a very slight looseness to it. See Fig..

    • Too Loose

    • Correct Position of Actuating Lever

    • Too Tight

    • Correct Cable Adjustment

    1. Actuating Lever

    Fig. 2, Parking Brake Cable Installation (typical)

  9. Set the parking brake.
  10. Test the parking brake before returning the vehicle to service.
Note:
Parent topic: Brakes
Document Number: 0000120772
Manual Publication Date: 2025-01-08
Topic Publication Date: 2025-01-08