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 Brake System Diagnosis

2

Inspect the hydraulic brake system for leaks. Refer to Brake Fluid Leak .

Are there any leaks?

--

Go to Step 3

Go to Step 5

3

  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 the engine to OFF.
  5. Inspect the hydraulic brake system for leaks.

Has the leak returned?

--

Go to Step 4

Go to Step 27

4

Replace the brake hose or pipe as necessary.

Is the repair complete?

--

Go to Step 27

--

5

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.

Do any of the above conditions apply?

--

Go to Step 6

Go to Step 7

6

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

Is the repair complete?

--

Go to Step 27

--

7

Inspect the following brake caliper assembly components for corrosion:

    • Mounting bolts
    • Sleeves
    • Steering knuckle
    • Brake caliper
    • Brake caliper piston

Refer to Brake Caliper Inspection in Disc Brakes.

Are any of the above components corroded or sticking?

--

Go to Step 8

Go to Step 9

8

Replace the corroded components. Refer to Brake Caliper Overhaul in Disc Brakes.

Is the repair complete?

--

Go to Step 27

--

9

Inspect the brake assembly for loose, missing or broken components.

Refer to Brake Pad Inspection in Disc Brakes.

Are there loose, missing or broken brake assembly components?

--

Go to Step 10

Go to Step 11

10

Tighten or replace the components as necessary. Refer to Brake Pads Replacement in Disc Brakes.

Is the repair complete?

--

Go to Step 27

--

11

  1. Inspect the brake pedal assembly for bent or misaligned components.
  2. Inspect the brake pedal for interference (binding) between the pedal and the booster input rod.

Is the brake pedal binding?

--

Go to Step 12

Go to Step 13

12

  1. Disassemble and realign or replace components as necessary.
  2. Replace the brake pedal if necessary.
  3. Refer to Brake Pedal Replacement .

Is the repair complete?

--

Go to Step 27

--

13

Check the brake pedal for interference with other components. Inspect the brake pedal area for the following:

    • loose or misaligned the trim panels
    • loose components, wiring harnesses or aftermarket devices

Are there any loose or interfering components?

--

Go to Step 14

Go to Step 15

14

Realign or reposition components as necessary.

Is the repair complete?

--

Go to Step 27

--

15

Inspect the vehicle for collapsed, bent or kinked brake lines or hoses.

Are the brake hoses or the brake pipes collapsed, bent, or kinked?

--

Go to Step 16

Go to Step 17

16

Reroute or replace the brake hoses or pipes as necessary.

Is the repair complete?

--

Go to Step 27

--

17

  1. Remove the master cylinder reservoir cover.
  2. Rapidly apply the brake pedal 3 cm (1 in), observing the brake fluid in the reservoir.

Does the fluid surface in the forward reservoir show movement or spouting?

--

Go to Step 18

Go to Step 19

18

  1. Install the master cylinder reservoir cover.
  2. Loosen the master cylinder mounting nuts 13 mm (½ in).
  3. Separate the master cylinder from the hydraulic brake booster.
  4. Apply the brake pedal 3 cm (1 in).

Does the booster output rod move?

--

Go to Step 19

Go to Step 20

19

Replace the master cylinder. Refer to Master Cylinder Replacement .

Is the repair complete?

--

Go to Step 27

--

20

Replace the brake booster. Refer to Power Brake Booster Replacement .

Is the repair complete?

--

Go to Step 27

--

21

Remove the master cylinder cover and inspect the brake fluid for contamination.

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 27

--

23

Check the master cylinder outlet ports for restricted passages. Refer to Hydraulic Brake System Bleeding .

Are the outlet ports restricted?

--

Go to Step 24

Go to Step 25

24

  1. Overhaul the master cylinder. Refer to Master Cylinder Overhaul .
  2. Flush the hydraulic brake system. Refer to Hydraulic Brake System Bleeding .

Is the repair complete?

--

Go to Step 27

--

25

Check the brake pipes and the brake hoses for restricted passages. Refer to Hydraulic Brake System Bleeding .

Check for the following:

    • low fluid or no fluid output
    • spurting of fluid while pressing the brake pedal
    • particles suspended in the fluid

Do any of the above conditions apply?

--

Go to Step 27

System OK

26

  1. Determine the area of the restriction. This will involve the disassembly of individual brake lines and checking for low fluid output.
  2. Flush the individual brake line or the brake hose.
  3. If the restriction cannot be removed, replace the brake hose or the brake pipe as necessary.
  4. Flush the hydraulic brake system. Refer to Hydraulic Brake System Bleeding .

Is the repair complete?

--

Go to Step 27

--

27

Verify proper brake system operation.

Does the original condition still exist?

--

Go to Step 1

System OK