GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Were you sent here from the Hydraulic Brake Symptom table?

Go to Step 2

Go to Diagnostic Starting Point - Hydraulic Brakes

2

Inspect the hydraulic brake system for proper operation. Refer to Hydraulic Brake System Diagnosis .

Did you find and correct a condition?

Go to Step 7

Go to Step 3

3

Inspect the disc brake system for proper operation. Refer to Disc Brake System Diagnosis .

Did you find and correct a condition?

Go to Step 7

Go to Step 4

4

Inspect the drum brake system, if equipped, for proper operation. Refer to Drum Brake System Diagnosis .

Did you find and correct a condition?

Go to Step 7

Go to Step 5

5

  1. Separate the master cylinder from the vacuum brake booster. Do not disconnect any brake pipes. Refer to Master Cylinder Replacement .
  2. Inspect the rear of the master cylinder for a brake fluid leak.
  3. Inspect for brake fluid in the vacuum brake booster.

Did you find a brake fluid leak?

Go to Step 6

Go to Diagnostic Starting Point - Hydraulic Brakes

6

Replace the brake master cylinder and the vacuum brake booster. Refer to Master Cylinder Replacement and Power Vacuum Brake Booster Replacement .

Did you complete the replacement?

Go to Step 7

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7

  1. Install or connect components that were removed or disconnected during diagnosis.
  2. Road test the vehicle to confirm proper operation. Refer to Brake System Vehicle Road Test .

Is the condition still present?

Go to Step 2

System OK