GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the Hydraulic Brake System Diagnostic Check performed?

--

Go to Step 2

Go to Hydraulic Brake Diagnostic System Check

2

Inspect the vehicle for overloading.

Is there excessive vehicle weight?

--

Go to Step 3

Go to Step 4

3

Remove the extra weight from the vehicle.

Has the excessive weight been removed?

--

Go to Step 29

--

4

Inspect the disc brake pads and brake shoe linings for the following:

    • Excessive wear
    • Uneven wear
    • Abuse
    • Contaminated lining material
    • Incorrect lining material

Refer to Brake Pad Inspection in Disc Brakes and Brake Shoe Inspection in Drum Brakes.

Do any of the above conditions apply?

--

Go to Step 5

Go to Step 6

5

Replace the brake linings. Refer to Brake Pads Replacement in Disc Brakes and Brake Shoe Replacement in Drum Brakes.

Is the repair complete?

--

Go to Step 29

--

6

Inspect the brake rotor surface for excessive thickness variation. Refer to Brake Rotor Thickness Variation Check in Disc Brakes.

Is the rotor thickness variation beyond specification?

--

Go to Step 7

Go to Step 8

7

  1. Resurface the brake rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
  2. If refinishing the brake rotor results in a thickness that is less than the thinnest (Refinished) thickness, replace the rotor. Refer to Component Specifications or Brake Rotor Replacement in Disc Brakes.

Is the repair complete?

--

Go to Step 29

--

8

Inspect the brake rotors for excessive lateral runout. Refer to Brake Rotor Lateral Runout Check .

Is the brake rotor runout excessive?

--

Go to Step 9

Go to Step 10

9

  1. Resurface the brake rotor. Refer to Brake Rotor Refinishing in Disc Brakes.
  2. If refinishing the brake rotor results in a thickness that is less than the thinnest (Refinished) thickness, replace the rotor. Refer to Brake Rotor Replacement in Disc Brakes.

Is the repair complete?

--

Go to Step 29

--

10

Inspect brake assembly for missing or loose attachments. Refer to Brake Pad Inspection in Disc Brakes or Brake Shoe Inspection in Drum Brakes.

Are there missing attachments?

--

Go to Step 11

Go to Step 12

11

Tighten or replace the attachments as necessary.

Is the repair complete?

--

Go to Step 29

--

12

Inspect the drum brakes for improper adjustment. Refer to Drum Brake Adjustment in Drum Brakes.

Are the brakes improperly adjusted?

--

Go to Step 13

Go to Step 14

13

Adjust the drum brakes properly. Refer to Drum Brake Adjustment in Drum Brakes.

Is the repair complete?

--

Go to Step 29

--

14

Inspect the master cylinder for leakage. Refer to Master Cylinder Diagnosis .

Is the master cylinder leaking?

--

Go to Step 15

Go to Step 16

15

Overhaul the master cylinder. Refer to Master Cylinder Overhaul .

Is the repair complete?

-

Go to Step 29

--

16

Inspect the hydraulic brake system for leaks.

Refer to Brake Fluid Leak .

Is there any sign of leakage?

--

Go to Step 17

Go to Step 19

17

  1. Tighten the brake hose or pipe fittings. Refer to Fastener Tightening Specifications .
  2. Start the engine.
  3. Press the brake pedal several times.
  4. Turn OFF the engine.
  5. Inspect the hydraulic brake system for leaks.

Has the leak returned?

--

Go to Step 18

Go to Step 19

18

Replace the brake hose or pipe as necessary.

Is the repair complete?

--

Go to Step 29

--

19

Inspect the brake system for air. Refer to Hydraulic Brake System Bleeding .

Is there air in the system?

--

Go to Step 20

Go to Step 21

20

Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding .

Is the repair complete?

--

Go to Step 29

--

21

Inspect the brake fluid for contamination. Refer to Brake Fluid and Brake Fluid Handling .

Is the brake fluid contaminated?

--

Go to Step 22

Go to Step 23

22

Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Step 29

-

23

Inspect the wheel cylinders for leakage. Does the wheel cylinder show signs of leakage?

--

Go to Step 24

Go to Step 25

24

Overhaul or replace the wheel cylinder. Refer to Wheel Cylinder Overhaul or Wheel Cylinder Replacement in Drum Brakes.

Is the repair complete?

--

Go to Step 29

--

25

Inspect the rear axle oil seal for leakage.

Is the seal leaking?

--

Go to Step 26

Go to Step 27

26

Replace the rear axle oil seal. Refer to Rear Oil Seal and/or Bearing Replacement in Rear Drive Axle.

Is the repair complete?

--

Go to Step 29

--

27

Inspect the brake caliper for leakage. Does the brake caliper show signs of leakage?

--

Go to Step 28

Go to Step 29

28

Overhaul or replace the brake caliper. Refer to Brake Caliper Overhaul or Brake Caliper Replacement in Disc Brakes.

Is the repair complete?

--

Go to Step 29

--

29

Verify the proper brake system operation.

Does the original condition still exist?

--

Go to Step 30

Go to Hydraulic Brake Diagnostic System Check

30

Verify customer complaint.

Is the repair complete?

--

Go to Step 1

Go to Hydraulic Brake Diagnostic System Check