GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the Hydraulic Brake Diagnostic System 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 Hydraulic Brake Diagnostic System Check

--

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 exist?

--

Go to Step 5

Go to Step 6

5

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

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

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 greater than the specified value?

0.013 mm (0.005 in).

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 Brake Rotor Replacement in Disc Brakes.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

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 rotors 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 Hydraulic Brake Diagnostic System Check

--

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.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

12

  1. Remove the brake drum. Refer to Brake Drum Replacement in Drum Brakes.
  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 Hydraulic Brake Diagnostic System Check

--

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

Replace the master cylinder. Refer to Master Cylinder Replacement .

Is the repair complete?

-

Go to Hydraulic Brake Diagnostic System Check

--

16

Inspect the hydraulic brake system for leaks.

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. Refer to Front Brake Hose Replacement , Rear Brake Hose Replacement or ISO Flares Replacement .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

19

Inspect the brake system for air. Refer 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 Hydraulic Brake Diagnostic System Check

--

21

Inspect the brake fluid for contamination.

Is the brake fluid contaminated?

--

Go to Step 22

Go to Step 23

22

  1. Replace all rubber brake system components. Refer to Master Cylinder Replacement , Front Brake Hose Replacement , Rear Brake Hose Replacement , Brake Caliper Overhaul , and Wheel Cylinder Overhaul .
  2. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

23

  1. Remove the brake drum. Refer to Brake Drum Replacement in Drum Brakes.
  2. Inspect the wheel cylinder 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 Hydraulic Brake Diagnostic System Check

--

25

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

Does the brake caliper show signs of leakage?

--

Go to Step 26

Go to Step 27

26

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

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

27

Verify proper brake system operation.

Does the original condition still exist?

--

Go to Step 1

System OK