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.

Refer to Loading Your Vehicle in the Vehicle Owner's Manual.

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 28

--

4

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

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

Refer to Brake Pad Inspection in Disc Brakes or 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 28

--

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?

0.010 mm (0.003 in).

Go to Step 7

Go to Step 8

7

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

Is the repair complete?

--

Go to Step 28

--

8

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

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. Check the thickness of the rotor. Refer to Component Specifications in Disc Brakes.
  3. If refinishing the brake rotor results in a thickness that is less than the thinnest (Refinishing) thickness, replace the rotor. Refer to Brake Rotor Replacement in Disc Brakes.

Is the repair complete?

--

Go to Step 28

--

10

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

Are there missing attachments?

--

Go to Step 11

Go to Step 12

11

Tighten the attachments.

Is the repair complete?

--

Go to Step 28

--

12

  1. Remove the brake drum.
  2. 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 28

--

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 28

--

16

Inspect the hydraulic brake system for leaks.

Refer to Brake Fluid Leak and Brake Hose and Pipe Diagnosis .

Is there any sign of leakage?

--

Go to Step 17

Go to Step 18

17

Tighten the brake hose or pipe fittings. Refer to Fastener Tightening Specifications .

Is the repair complete?

--

Go to Step 28

--

18

Inspect the brake system for air.

Is there air in the system?

--

Go to Step 19

Go to Step 20

19

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

Is the repair complete?

--

Go to Step 28

--

20

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

Is the brake fluid contaminated?

--

Go to Step 21

Go to Step 22

21

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

Is the repair complete?

--

Go to Step 28

--

22

  1. Remove the brake drum.
  2. Inspect the wheel cylinder for leakage.

Does the wheel cylinder show signs of leakage?

--

Go to Step 23

Go to Step 24

23

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 28

--

24

Inspect the rear axle oil seal for leakage.

Is the seal leaking?

--

Go to Step 25

Go to Step 26

25

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 28

--

26

  1. Remove the brake caliper. Refer to Brake Caliper Replacement in Disc Brakes.
  2. Inspect the brake caliper for leakage. Refer to Brake Caliper Inspection .

Does the brake caliper show signs of leakage?

--

Go to Step 27

System OK

27

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

Is the repair complete?

--

Go to Step 28

--

28

Verify proper brake system operation.

Does the original condition still exist?

--

Verify the customer complaint. Begin the diagnosis again. Go to Step 1

System OK