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.

Were you sent here from a Hydraulic Brake Symptom table?

Go to Step 4

Go to Step 2

Were you sent here from a Park Brake Symptom table?

Go to Step 4

Go to Step 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 in Hydraulic Brakes

1. Raise and support the vehicle with the rear axle supported by jack stands. Refer to Lifting and Jacking the Vehicle in General Information.
2. With the park brake RELEASED using the manual override release lever, 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 11

Go to Step 5

1. Shift the transmission into PARK or NEUTRAL to disable the park brake automatic release system.
2. Apply the park brake.
3. 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 6

Go to Step 7

1. Release the park brake using the manual override release lever.
2. Rotate the rear wheels to check the rear brakes for a significant reduction in the amount of drag.

Did the rear brakes exhibit a significant reduction in the amount of drag?

Go to Step 21

Go to Step 11

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 8

Go to Step 9

Reconnect or replace the park brake cables as necessary. Refer to the following procedures:

Did you complete the repair and/or replacement?

Go to Step 9

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Inspect the adjustment of the park brake. Refer to Park Brake Adjustment .

Was the park brake adjusted properly?

Go to Step 11

Go to Step 10

Adjust the park brake. Refer to Park Brake Adjustment .

Were you able to adjust the park brake?

Go to Step 16

Go to Step 11

1. Disconnect the rear park brake cables from the brake caliper apply levers.
2. Using a wrench on each of the caliper piston apply lever bolts, apply and release the levers. Observe for free motion during apply and free and complete return when released.

Did the brake caliper piston apply levers move freely during apply, and freely and completely return during release?

Go to Step 13

Go to Step 12

Replace the rear brake caliper, or calipers as necessary. Refer to Rear Brake Caliper Replacement in Disc Brakes.

Did you complete the replacement?

Go to Step 13

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Have an assistant apply and manually release the park brake, while you observe the park brake cables for free movement.

Did the park brake cables move freely?

Go to Step 14

Go to Step 17

Inspect the adjustment of the park brake. Refer to Park Brake Adjustment .

Was the park brake adjusted properly?

Go to Step 16

Go to Step 15

Adjust the park brake. Refer to Park Brake Adjustment .

Were you able to adjust the park brake?

Go to Step 16

Go to Step 24

1. With the transmission still in PARK or NEUTRAL, to disable the park brake automatic release system, apply the park brake.
2. Attempt to rotate the rear wheels to check the rear brakes for a significant amount of drag.
3. Release the park brake using the manual override release lever.
4. 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 34

Return to Symptom Table

Disconnect the park brake cable connections that are accessible on the UNDERSIDE of the vehicle one at a time and inspect each cable for free movement.

Do any of the park brake cables accessible on the underside of the vehicle require replacement?

Go to Step 18

Go to Step 19

Replace any of the park brake cables that do not have free movement - not releasing properly. Refer to the following procedures:

Did you complete the replacement?

Go to Step 19

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1. Disconnect the front park brake cable connection accessible INSIDE the vehicle at the park brake pedal assembly and inspect for free movement.
2. Replace the front park brake cable if the cable does not have free movement. Refer to Parking Brake Front Cable Replacement .

Did you find and correct a condition?

Go to Step 22

Go to Step 20

Replace the park brake pedal assembly - not releasing properly. Refer to Parking Brake Lever Pedal Assembly Replacement .

Did you complete the replacement?

Go to Step 23

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Inspect the adjustment of the park brake. Refer to Park Brake Adjustment .

Is the park brake adjusted properly?

Go to Step 34

Go to Step 22

Adjust the park brake. Refer to Park Brake Adjustment .

Were you able to adjust the park brake?

Go to Step 25

Go to Step 24

Adjust the park brake. Refer to Park Brake Adjustment .

Were you able to adjust the park brake?

Go to Step 25

Return to Symptom Table

1. Replace the component that is used to adjust the park brake system. Refer to Park Brake Cable Equalizer Replacement .
2. Adjust the park brake. Refer to Park Brake Adjustment .

Did you complete the replacement and adjustment?

Go to Step 25

Return to Symptom Table

Verify the operation system of the park brake pedal automatic release system:

1. Apply the park brake.
2. Start the engine and allow the engine to idle.
3. Shift the transmission into REVERSE or any FORWARD gear.
4. Observe the park brake pedal assembly for automatic release of the pedal.

Did the park brake pedal assembly release automatically?

Go to Step 33

Go to Step 26

1. Disconnect the vacuum source hose from the park brake release vacuum actuator.
2. Connect a vacuum gage to the actuator vacuum source hose.
3. Start the engine and allow the engine to idle.
4. Shift the transmission into REVERSE or any FORWARD gear.
5. Measure the vacuum at the release actuator vacuum source hose.

Specification
47-68 kPa (14-20 in Hg)

Is the vacuum reading within the specified range?

Go to Step 28

Go to Step 27

Repair the vacuum source fault. Refer to HVAC Schematics in HVAC Systems - Automatic.

Did you find and correct the condition?

Go to Step 28

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1. Connect a hand vacuum pump to the park brake release vacuum actuator.
2. Apply 47-68 kPa (14-20 in Hg) to the release actuator.

Does the park brake release vacuum actuator hold vacuum?

Go to Step 29

Go to Step 30

Did the park brake pedal assembly release?

Go to Step 33

Go to Step 32

Replace the park brake release vacuum actuator. Refer to Park Brake Release Solenoid Replacement .

Did you complete the replacement?

Go to Step 31

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1. Connect a hand vacuum pump to the park brake release vacuum actuator.
2. Apply 47-68 kPa (14-20 in Hg) to the release actuator.

Did the park brake pedal assembly release?

Go to Step 33

Go to Step 32

Replace the park brake pedal assembly. Refer to Parking Brake Lever Pedal Assembly Replacement .

Did you complete the replacement?

Go to Step 33

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1. With the transmission still in PARK or NEUTRAL to disable the park brake automatic release system, apply the park brake.
2. Attempt to rotate the rear wheels to check the rear brakes for a significant amount of drag.
3. Release the park brake using the manual override release lever.
4. 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 34

Return to Symptom Table

Install or connect any components that were removed or disconnected during diagnosis.

Did you complete the operation?

Park Brake System OK

Return to Symptom Table

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