Step
| Action
| Yes
| No
|
DEFINITION: Brake system does not fully release or has delayed release; vehicle motion may be hindered by brake system without applying brakes.
|
1
| Were you sent here from the Hydraulic Brake Symptom table?
| Go to
Step 2
| Go to
Diagnostic Starting Point - Hydraulic Brakes
|
2
| Is the vehicle equipped with an adjustable stop lamp switch and/or an adjustable cruise control release switch?
| Go to
Step 3
| Go to
Step 4
|
3
|
- Inspect the stop lamp switch for proper adjustment to ensure that the brake pedal is fully releasing.
- Inspect the cruise control release switch, if equipped, for proper adjustment to ensure that the brake pedal is fully releasing.
Did you find and correct a condition?
| Go to
Step 15
| Go to
Step 4
|
4
| Is the vehicle equipped with a drum-in-rotor type of park brake system?
| Go to
Step 5
| Go to
Step 7
|
5
| Ensure the park brake shoes are not adjusted too tightly, possibly causing drag under certain conditions.
Are the park brake shoes adjusted too tightly?
| Go to
Step 6
| Go to
Step 8
|
6
|
- Clean and inspect the park brake shoes for excessive wear and/or damage.
- Inspect the drum portion of the rotors for excessive wear, blueing discoloration and heat spots.
- If any of these conditions are present, replace the affected components.
- Adjust the park brake system.
Did you find and correct a condition?
| Go to
Step 15
| Go to
Step 8
|
7
|
- Inspect the drum brake system, if equipped, for the following conditions:
| • | Weak or damaged return spring or springs |
| • | Distorted or damaged linings |
| • | Out of round or damaged drum |
| • | Weak or damaged hold down spring or springs |
| • | Lack of lubrication on backing plate |
| • | Distorted or damaged backing plate |
- Adjust, repair or replace components as necessary. Refer to
Drum Brake System Diagnosis.
Did you find and correct a condition?
| Go to
Step 15
| Go to
Step 8
|
8
| Inspect the park brake system for proper operation. Refer to
Park Brake System Diagnosis.
Did you find and correct a condition?
| Go to
Step 15
| Go to
Step 9
|
9
|
- Inspect the disc brake system for the following conditions:
| • | Binding, incorrectly installed or missing caliper hardware and/or lining hardware--ensure free movement of linings and of caliper, if equipped with sliding type caliper. |
| • | Lack of lubrication or excessive corrosion on metal to metal contact surfaces |
| • | Distorted or damaged linings |
| • | Damaged or excessively worn caliper hardware and/or lining hardware |
| • | Bent or damaged caliper or mounting component |
- Adjust, repair or replace components as necessary. Refer to
Disc Brake System Diagnosis.
Did you find and correct a condition?
| Go to
Step 15
| Go to
Step 10
|
10
|
- Separate the brake booster pushrod from the brake pedal.
- Inspect the brake corners to determine if the brake drag condition is still present.
Do the brake corners still exhibit the brake drag condition?
| Go to
Step 12
| Go to
Step 11
|
11
|
- Inspect the pushrod for improper positioning and/or damage. Correctly position or replace the pushrod if necessary.
- Inspect the brake pedal assembly for damage and replace if necessary.
Did you complete the repair or replacement?
| Go to
Step 15
| --
|
12
|
- For vacuum boost systems, disconnect the vacuum check valve from the booster to relieve vacuum reserve.
- Separate the master cylinder from the brake booster. Do not disconnect any brake pipes.
- Inspect the brake corners to determine if the brake drag condition is still present.
Do the brake corners still exhibit the brake drag condition?
| Go to
Step 14
| Go to
Step 13
|
13
| Replace the brake booster assembly.
Did you complete the replacement?
| Go to
Step 15
| --
|
14
|
- Inspect the hydraulic brake system for the following conditions:
| • | Improper operation of wheel cylinder pistons, if equipped |
| • | Improper operation of caliper pistons |
| • | Contaminated brake fluid |
| • | Internally damaged flexible brake hoses; hindering brake release |
| • | Damaged or improperly operating master cylinder |
- Adjust, repair or replace components as necessary. Refer to
Hydraulic Brake System Diagnosis.
Did you find and correct a condition?
| Go to
Step 15
| Go to
Diagnostic Starting Point - Hydraulic Brakes
|
15
|
- Install or connect components that were removed or disconnected during diagnosis.
- Road test the vehicle in order to confirm proper operation. Refer to
Brake System Vehicle Road Test.
Is the condition still present?
| Go to
Step 2
| System OK
|
