Park Brake System Diagnosis

Step	Action	Yes	No
DEFINITION: This diagnostic table is designed to diagnose ONLY the components of the PARK brake system in order to determine if the PARK brake system is operating properly. You will be directed by the appropriate Symptom table to go to other brake system diagnostic tables as appropriate.
1	Were you sent here from a Hydraulic Brake Symptom table?	Go to Step 4	Go to Step 2
2	Were you sent here from a Park Brake Symptom table?	Go to Step 4	Go to Step 3
3	Is the symptom related to the ability of the park brake system to hold and/or release?	Go to Diagnostic Starting Point - Park Brake	Go to Diagnostic Starting Point - Hydraulic Brakes
4	Raise and support the vehicle with the rear axle supported by jack stands. Refer to Lifting and Jacking the Vehicle . With the park brake RELEASED, attempt to rotate the rear wheels to check the rear brakes for a significant amount of drag. Do the rear brakes have a significant amount of drag?	Go to Step 9	Go to Step 5
5	Apply the park brake. Attempt to rotate the rear wheels to check the rear brakes for a significant amount of drag. Do the rear brakes have a significant amount of drag?	Go to Step 19	Go to Step 7
6	Visually check the park brake cable connections and the cables that are accessible on the UNDERSIDE of the vehicle for disconnections and/or damage. Were any or the park brake cables disconnected and/or damaged?	Go to Step 7	Go to Step 8
7	Reconnect or replace the park brake cables as necessary. Refer to the following procedures as necessary: Park Brake Cable Replacement - Front Park Brake Cable Replacement - Left Rear Park Brake Cable Replacement - Right Rear Did you complete the repair and/or replacement?	Go to Step 19	-
8	Check the adjustment of the park brake and adjust if necessary. Refer to Park Brake Adjustment (L26 and L32) . Was the park brake adjusted properly?	Go to Step 19	Go to Step 9
9	Disconnect the rear park brake cables from the brake caliper piston apply levers. Apply and release the caliper piston apply levers. Observe for the following: Free motion of the piston apply levers during apply and free and complete return to the stops when released Free movement of the caliper pistons during apply and free return movement when released Did the brake caliper piston apply levers move freely during apply and freely and completely return to the stops during release; and did the caliper pistons exhibit freedom of movement during apply and release?	Go to Step 11	Go to Step 10
10	Replace the appropriate rear brake caliper. Refer to Rear Brake Caliper Replacement (J65, JL9) or Rear Brake Caliper Replacement (Z7U) . Did you complete the replacement?	Go to Step 19	-
11	With the aid of an assistant, apply and release the parking brake while observing the cables for free movement. Do the park brake cables move freely?	Go to Step 12	Go to Step 14
12	Check the adjustment of the park brake and adjust if necessary. Refer to Park Brake Adjustment (L26 and L32) . Did you find and correct the condition?	Go to Step 19	Go to Step 13
13	Disconnect the park brake cable connections that are accessible on the UNDERSIDE of the vehicle one at a time and check each cable for free movement. Do any of the park brake cables accessible on the underside of the vehicle require replacement?	Go to Step 14	Go to Step 15
14	Replace any of the park brake cables that do not have free movement. Refer to the following procedures as necessary: Park Brake Cable Replacement - Front Park Brake Cable Replacement - Left Rear Park Brake Cable Replacement - Right Rear Did you complete the replacement?	Go to Step 19	-
15	Disconnect the front park brake cable connection accessible INSIDE the vehicle at the park brake pedal assembly and check for free movement. Replace the front park brake cable if it does not have free movement. Refer to Park Brake Cable Replacement - Front . Did you find and correct a condition?	Go to Step 19	Go to Step 16
16	Inspect the park brake pedal for proper operation and replace if necessary. Refer to Park Brake Pedal Assembly Replacement . Did you find and correct a condition?	Go to Step 19	Go to Step 17
17	Check the adjustment of the park brake and adjust if necessary. Refer to Park Brake Adjustment (L26 and L32) . Did you find and correct a condition?	Go to Step 19	Go to Step 18
18	Replace the component that is used to adjust the park brake system. Refer to Park Brake Cable Equalizer Replacement . Adjust the park brake. Refer to Park Brake Adjustment (L26 and L32) . Did you complete the replacement and adjustment?	Go to Step 19	Go to Symptoms - Park Brake
19	Install or connect any components that were removed or disconnected during diagnosis. Did you complete the operation?	Park Brake System OK Go to Symptoms - Park Brake	-