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 3	Go to Step 2
2	Were you sent here from a Park Brake Symptom table?	Go to Step 3	Go to Diagnostic Starting Point - Vehicle
3	Raise and support the vehicle with the rear axle supported by jack stands. Refer to Lifting and Jacking the Vehicle . Shift the transmission into NEUTRAL. 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 8	Go to Step 4
4	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 18	Go to Step 5
5	Visually inspect the park brake cable connections and the cables that are accessible on the UNDERSIDE of the vehicle for disconnections and/or damage. Were any of the park brake cables disconnected and/or damaged?	Go to Step 6	Go to Step 7
6	Reconnect or replace the park brake cables as necessary. Refer to the following procedures as necessary: Parking Brake Lever Replacement Parking Brake Rear Cable Replacement Did you complete the repair and/or replacement?	Go to Step 18	-
7	Check the adjustment of the park brake. Refer to Parking Brake Adjustment . Did you find and correct the condition?	Go to Step 18	Go to Step 8
8	CAUTION: Do not depress the brake pedal with the brake rotors and/or the brake drums removed, or with the brake calipers repositioned away from the brake rotors, or damage to the brake system may result. Remove the rear brake rotors. Refer to Rear Brake Rotor Replacement (LFX) , Rear Brake Rotor Replacement (L99, LS3, LSA) . Inspect the park brake shoe hardware for looseness, damaged, broken or missing components. Check the park brake actuators for a seized condition. Does the park brake hardware and/or the park brake actuators require replacement?	Go to Step 9	Go to Step 10
9	Replace park brake hardware components as necessary. Refer to Parking Brake Shoe Replacement . Replace the park brake actuators as necessary. Refer to Parking Brake Actuator Replacement . Did you find and correct the condition?	Go to Step 18	Go to Step 17
10	Have an assistant apply and release the park brake, while you observe the park brake cables for free movement. Did the park brake cables move freely?	Go to Step 11	Go to Step 13
11	Check the adjustment of the park brake. Refer to Parking Brake Adjustment . Did you find and correct the condition?	Go to Step 18	Go to Step 12
12	With the transmission still in NEUTRAL, apply the park brake. Attempt to rotate the rear wheels to check the rear brakes for a significant amount of drag. Release the park brake. Rotate the rear wheels to check the rear brakes for a significant reduction of drag. Did the park brake apply and release properly?	Go to Step 18	Go to Symptoms - Park Brake
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 - not releasing properly. Refer to the following procedures as necessary: Parking Brake Lever Replacement Parking Brake Rear Cable Replacement Did you complete the replacement?	Go to Step 18	-
15	Disconnect the front park brake cable connection accessible INSIDE the vehicle at the park brake lever assembly and check for free movement. Replace the front park brake cable if it does not have free movement. Refer to Parking Brake Lever Replacement . Did you find and correct a condition?	Go to Step 18	Go to Step 16
16	Inspect the park brake lever assembly for proper operation and replace if necessary. Refer to Parking Brake Lever Replacement . Did you find and correct the condition?	Go to Step 18	Go to Step 17
17	Replace the component that is used to adjust the park brake system. Refer to Parking Brake Lever Replacement . Adjust the park brake. Refer to Parking Brake Adjustment . Did you complete the replacement and adjustment?	Go to Step 18	Go to Symptoms - Park Brake
18	Install or connect any components that were removed or disconnected during diagnosis. Verify the operation of the park brake system. Does the park brake operate correctly?	System OK	Go to Symptoms - Park Brake