GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

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

Has the leak returned?

--

Go to Step 4

Go to Step 29

4

Replace the brake hose or the brake pipe as necessary. Refer to the appropriate procedure:

    •  Brake Pipe Replacement

Is the repair complete?

--

Go to Step 29

--

5

Inspect the disc brake pads for the following conditions:

    • 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 Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.

Is the repair complete?

--

Go to Step 29

--

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 the appropriate procedure in Disc Brakes:

Is the repair complete?

--

Go to Step 29

--

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 Front Disc Brake Pads Replacement or Rear Disc Brake Pads Replacement in Disc Brakes.

Is the repair complete?

--

Go to Step 29

--

11

  1. Inspect the rear calipers for leakage.
  2. Inspect the rear calipers for binding.

Is the rear caliper leaking or binding?

--

Go to Step 12

Go to Step 13

12

Overhaul or replace the rear caliper. Refer to Rear Brake Caliper Overhaul in Disc Brakes.

Is the repair complete?

--

Go to Step 29

--

13

  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 14

Go to Step 15

14

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

Is the repair complete?

--

Go to Step 29

--

15

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

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

Are there any loose or interfering components?

--

Go to Step 16

Go to Step 17

16

Realign or reposition components as necessary.

Is the repair complete?

--

Go to Step 29

--

17

    • Inspect for collapsed , dented, or bent brake pipes. Refer to Brake Fluid Leak .
    • Inspect the brake hoses for sharp kinks. Refer to Brake Fluid Leak .

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

--

Go to Step 18

Go to Step 19

18

Reroute or replace the brake hoses or the brake pipes as necessary. Refer to the appropriate procedure:

Is the repair complete?

--

Go to Step 29

--

19

  1. Remove the master cylinder reservoir cap.
  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 20

Go to Step 21

20

  1. Install the master cylinder reservoir cover.
  2. Loosen the master cylinder mounting nuts 13 mm (1/2 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 21

Go to Step 22

21

Replace the master cylinder. Refer to Master Cylinder Replacement .

Is the repair complete?

--

Go to Step 29

--

22

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

Is the repair complete?

--

Go to Step 29

--

23

  1. Remove the master cylinder reservoir cover.
  2. Inspect the brake fluid for contamination. Refer to Brake Fluid and Brake Fluid Handling .

Is the brake fluid contaminated?

--

Go to Step 24

Go to Step 25

24

  1. Replace all rubber brake system components. Refer to Front Brake Caliper Overhaul or Rear Brake Caliper Overhaul in Disc Brakes.
  2. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Step 29

--

25

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

Are the outlet ports restricted?

--

Go to Step 26

Go to Step 27

26

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

Is the repair complete?

--

Go to Step 29

--

27

Inspect the brake pipes and the brake hoses for restricted passages. Refer to Hydraulic Brake System Flushing .

Inspect for the following conditions:

    • 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 29

System OK

28

  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. Refer to the appropriate procedure:
  4. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Step 29

--

29

Verify the proper brake system operation.

Does the brake system operate properly?

--

System OK

Go to Hydraulic Brake Diagnostic System Check