Pinpoint Test A: The Parking Brake Does Not Apply Or Does Not Hold Vehicle
- A1 CHECK THE PARKING BRAKE CONTROL
- Pull up the parking brake control handle.
Does the parking brake control move?
- Yes : GO to A2 .
- No : GO to A3.
- A2 INSPECT THE FOLLOWING PARKING BRAKE COMPONENTS NOTE: Have an assistant pull and release the parking brake to help isolate disconnected cables or cables that do not move.
- Parking brake control
- Front parking brake cable
- Rear parking brake cables and/or equalizer
- Rear brake caliper actuators
- Rear brake shoes and/or hardware
Is any damage found or are any components disconnected?
- Yes
: CONNECT the component(s) or INSTALL new parking brake component(s) as necessary.
ADJUST the parking brake cables.
REFER to: PARKING BRAKE CABLE ADJUSTMENT - VEHICLES WITH: REAR DRUM BRAKES .
REFER to: PARKING BRAKE CABLE ADJUSTMENT - VEHICLES WITH: REAR DISC BRAKES .
- No
: For drum brake vehicles, VERIFY that the rear shoes and brake drums are within thickness specifications.
REFER to: SPECIFICATIONS .
If the rear shoes and drums are OK, Adjust the rear brake shoes. REFER to: BRAKE SHOE ADJUSTMENT .
For disc brake vehicles, VERIFY that the rear pads and brake discs are within thickness specifications.
REFER to: SPECIFICATIONS .
If the rear pads and brake discs are OK, INSTALL new rear brake calipers. REFER to: BRAKE CALIPER .
- A3 ISOLATE THE PARKING BRAKE CONTROL AND FRONT PARKING BRAKE CABLE
- Disconnect the front parking brake cable from the rear parking brake cable equalizer.
- Pull up the parking brake control handle.
Does the parking brake control handle move?
- Yes
: For drum brake vehicles GO to A4
.
For disc brake vehicles GO to A5.
- No
: INSTALL a new parking brake control or a new front parking brake cable as necessary.
REFER to: PARKING BRAKE CONTROL .
- A4 ISOLATE THE REAR PARKING BRAKE CABLES (DRUM BRAKES)
- Disconnect the rear parking brake cable from the rear extension cable at the affected wheel end(s).
- While holding the cable conduit, attempt to slide the cable inside the conduit.
Does the cable slide freely inside the conduit?
- Yes : GO to A6.
- No
: INSTALL new rear parking brake cables.
REFER to: PARKING BRAKE CABLE - VEHICLES WITH: REAR DRUM BRAKES .
- A5 ISOLATE THE REAR PARKING BRAKE CABLES (DISC BRAKES)
- Disconnect the rear parking brake cable from the rear brake caliper at the affected wheel end(s).
- While holding the cable conduit, attempt to slide the cable inside the conduit.
Does the cable slide freely inside the conduit?
- Yes
: The parking brake system is operating normally at this time. INSPECT the rear brake components on the affected wheel end(s). INSTALL new rear brake components as necessary and ADJUST the parking brake cables.
REFER to: PARKING BRAKE CABLE ADJUSTMENT - VEHICLES WITH: REAR DISC BRAKES .
- No
: INSTALL new rear parking brake cables.
REFER to: PARKING BRAKE CABLE - VEHICLES WITH: REAR DISC BRAKES .
- A6 ISOLATE THE REAR EXTENSION CABLES (DRUM BRAKES)
- Remove the brake drum on the affected wheel end(s).
REFER to: BRAKE DRUM .
- Disconnect the rear extension cable from the brake shoe actuator lever on the affected wheel end(s) and while holding the rear cable conduit, attempt to slide the rear cable inside the conduit.
Does the cable slide freely inside the conduit?
- Yes
: The parking brake system is operating normally at this time. The concern may have been cause by a seized or binding rear brake component. INSPECT the rear brake components. INSTALL new component(s) as necessary. If the rear brake components are OK, CLEAN and LUBRICATE the brake backing plate.
REFER to: BRAKE SHOES .
ADJUST the parking brake cables.
REFER to: PARKING BRAKE CABLE ADJUSTMENT - VEHICLES WITH: REAR DRUM BRAKES .
- No
: INSTALL new rear extension cables as necessary and adjust the parking brake cables.
ADJUST the parking brake cables.
REFER to: PARKING BRAKE CABLE ADJUSTMENT - VEHICLES WITH: REAR DRUM BRAKES .
- Remove the brake drum on the affected wheel end(s).