Pinpoint Test A: The Parking Brake Does Not Apply

Parking Brake

Pinpoint Test A: The Parking Brake Does Not Apply

Normal Operation

The parking brake system is cable-actuated and controlled by an independent, foot-operated parking brake control that is not self-adjusting. The parking brake system is actuates when the parking brake control is applied. When the parking brake control is applied, tension is applied to the front parking brake cable. This tension pulls on both rear parking brake cables, which are attached to the brake caliper parking brake actuators and apply the brake pads.

This pinpoint test is intended to diagnose the following:

- Parking brake cables

- Parking brake control

- Rear brake calipers

PINPOINT TEST A : THE PARKING BRAKE DOES NOT APPLY

A1 CHECK THE PARKING BRAKE CONTROL

- Press the parking brake control pedal.

Does the parking brake control move?

Yes
GO to A2.

No
GO to A3.

A2 CHECK FOR BROKEN CABLES

- NOTE: Have an assistant press and release the parking brake pedal to help isolate disconnected cables or cables that do not move.

Inspect the following items for damage and correct connections:
- Parking brake control
- Front cable
- Equalizer
- LH rear cable
- RH rear cable
- Rear brake caliper actuators


Is any damage found or are any components disconnected?

Yes
CONNECT the component(s) or INSTALL new parking brake component(s) as necessary. TEST the system for normal operation.

No
VERIFY the rear pads are within thickness specifications. Refer to Specifications in Brakes and Traction Control.
If the rear pads are OK, INSTALL new rear brake calipers.

A3 ISOLATE THE PARKING BRAKE CONTROL AND FRONT PARKING BRAKE CABLE

- Disconnect the return spring from the equalizer.

- Relieve the tension in the parking brake cable by loosening the equalizer adjustment nut until the rear cables can be disconnected from the equalizer.

- Disconnect both rear cables from the equalizer.

- Press the parking brake control pedal.

Does the parking brake control pedal move?

Yes
GO to A4.

No
GO to A5.

A4 ISOLATE THE REAR PARKING BRAKE CABLES

- Disconnect the LH and RH parking brake cables from the brake calipers.






- While holding the cable conduit, attempt to slide the LH and the RH cables inside their conduits.

Do the cables slide freely inside their conduits?

Yes
INSTALL new rear brake caliper(s). ADJUST the parking brake cable. REFER to Parking Brake Cable Adjustment Adjustments.

No
INSTALL new rear brake cable(s). REFER to Parking Brake Cable - Rear, LH Parking Brake Cable - Rear, LH and/or Parking Brake Cable - Rear, RH Parking Brake Cable - Rear, RH. TEST the system for normal operation.

A5 ISOLATE THE FRONT PARKING BRAKE CABLE

- Remove the parking brake control adjustment nut and remove the front parking brake cable from the parking brake control.

- Attempt to slide the front parking brake cable inside the conduit.

Does the cable slide freely inside the conduit?

Yes
INSTALL a new parking brake control. REFER to Parking Brake Control Service and Repair. TEST the system for normal operation.

No
INSTALL a new front parking brake cable. REFER to Parking Brake Cable - Front Parking Brake Cable - Front. TEST the system for normal operation.