| Diagnosis and Testing Inspection and Verification - Verify the customer concern by operating the parking brake system.
- Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection Chart | Mechanical | Electrical | - Parking brake control
REFER to: Parking Brake Control (206-05, Removal and Installation).
- Cable and conduit
REFER to: Parking Brake Cable (206-05, Removal and Installation).
| - Parking brake warning circuit.
REFER to: Instrument Cluster (413-01, Diagnosis and Testing).
| - If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the concern is not visually evident, verify the symptom and refer to the Symptom Chart.
Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | The parking brake will not apply | * Parking brake control. * Cable and conduit. | * | | The parking brake will not release | * Parking brake control. * Cable and conduit. | * | Pinpoint Tests | PINPOINT TEST A : THE PARKING BRAKE WILL NOT APPLY | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: CHECK FOR MISADJUSTED REAR PARKING BRAKE CABLE | | | 1 Operate the parking brake control several times to adjust the cable. | | | Does the parking brake now engage correctly? Yes Vehicle OK No | | A2: CHECK FOR WORN BRAKE SHOES OR PADS | | | 1 Inspect the brake shoes or pads for excessive wear.
REFER to: Specifications (206-00, Specifications) /
Brake Shoes (206-02 Drum Brake, Removal and Installation) /
Brake Pads (206-04, Removal and Installation).
| | | Are the brake shoe linings or brake pads OK? Yes No INSTALL new brake shoes or pads.
REFER to: Brake Shoes (206-02 Drum Brake, Removal and Installation) /
Brake Pads (206-04, Removal and Installation).
TEST the system for normal operation. | | A3: CHECK FOR DAMAGED PARKING BRAKE CABLES | | | 1 Inspect the parking brake cables and conduits for damage, rust or fraying. | | | Are the parking brake cables and conduits OK? Yes CHECK for other causes such as loose parking brake control or conventional brake system components. No REPAIR or INSTALL cables and conduit as necessary. TEST the system for normal operation. | | PINPOINT TEST B : THE PARKING BRAKE WILL NOT RELEASE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: CHECK PARKING BRAKE CONTROL | | | 1 Raise and support the vehicle on a lift with the parking brake fully applied.
REFER to: Lifting (100-02, Description and Operation).
- With the aid of another technician, release the parking brake and check the operation of the brake cables and levers.
| | | Did the parking brake release? Yes CHECK the other causes such as conventional brake system components. REPAIR or INSTALL new components as necessary. No | | B2: CHECK PARKING BRAKE CABLES | | | 1 Loosen the parking brake cable tension. - Rotate the rear wheels by hand.
| | | Did the rear wheels turn freely? Yes INSTALL a new parking brake control.
REFER to: Parking Brake Control (206-05, Removal and Installation).
TEST the system for normal operation. No | | B3: CHECK FRONT PARKING BRAKE CABLE | | | 1 Disconnect the parking brake front cable and conduit from the rear brake cable and conduit at the equalizer. - Rotate the rear wheels by hand.
| | | Did the rear wheels turn freely? Yes INSTALL a new front parking brake cable and conduit.
REFER to: Parking Brake Cable (206-05, Removal and Installation).
TEST the system for normal operation. No | | B4: CHECK REAR PARKING BRAKE CABLES | | | 1 Disconnect the parking brake at the rear brakes, one at a time. - Rotate the wheel affected by the disconnected parking brake.
| | | Did the wheel turn freely? Yes INSTALL a new parking brake control lever on the rear drum brakes or caliper assembly on rear disc brakes.
REFER to: Brake Shoes (206-02 Drum Brake, Removal and Installation) /
Brake Caliper (206-04, Removal and Installation).
TEST the system for normal operation. No REFER to: Brake System (206-00, Diagnosis and Testing). | |
