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

Check the park brake lever for proper operation by doing the following:

  1. Turn the ignition ON.
  2. Press the park brake pedal until it stops. Verify the Brake Warning Lamp is ON.
  3. Pull the park brake release lever. Verify the Brake Warning Lamp is OFF.

Did the park brake warning lamp turn OFF and the pedal return to its original height?

--

Go to Step 4

Go to Step 3

3

  1. Check the park brake assembly for interference, binding or for broken components.
  2. Lubricate the park brake assembly.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

4

  1. Start the engine.
  2. Shift the vehicle into DRIVE.
  3. Attempt to move the vehicle by slowly pressing the accelerator pedal.

Does the engine rpm increase without the vehicle moving?

--

Go to Step 5

Go to Step 7

5

Inspect the park brake cables for corrosion, kinks, or interference with other components.

Are the park brake cables corroded, kinked, or interfering with other components?

--

Go to Step 6

Go to Step 7

6

Realign or replace the park brake cable(s). Refer to Parking Brake Front Cable Replacement or Parking Brake Rear Cable Replacement - Right Side or Parking Brake Rear Cable Replacement - Right Side in Park Brake.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

7

  1. Remove the brake drum.
  2. Inspect the brake linings for the following:
  3. • Excessive wear
    • Uneven wear
    • Abuse
    • Glazing
    • Contaminated lining material
    • Incorrect lining material

Refer to Brake Shoe Inspection in Drum Brakes.

Do any of the above conditions exist?

--

Go to Step 8

Go to Step 9

8

Replace the brake shoe linings. Refer to Brake Shoe Replacement in Drum Brakes.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

9

Inspect the brake shoe mounting hardware and springs for corrosion or binding.

Is the mounting hardware or springs corroded or binding?

--

Go to Step 10

Go to Step 11

10

Replace the mounting hardware or springs as necessary.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

11

Inspect the park brake lever for corrosion and free movement without binding.

Does the park brake lever bind?

--

Go to Step 12

Go to Step 13

12

Clean the park brake lever components and check for proper movement.

If the park brake lever still does not move freely, replace the park brake lever. Refer to Park Brake Lever Assembly Replacement in Park Brake.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

13

Inspect the disc brake caliper guide pins for corrosion. Refer to Brake Pads Replacement in Disc Brakes.

Are the guide pins corroded?

--

Go to Step 14

Go to Step 15

14

Replace the guide pins as necessary.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

15

  1. Remove the caliper piston. Refer to Brake Caliper Overhaul in Disc Brakes.
  2. Inspect the caliper bore and the piston for scoring, corrosion, or pitting.

Is there damage to the piston or caliper bore?

--

Go to Step 16

Go to Step 17

16

Replace the piston or the caliper as needed.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

17

  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 18

Go to Step 19

18

Disassemble and realign or replace components as necessary.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

19

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

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

Are there any loose or interfering components?

--

Go to Step 20

Go to Step 21

20

Realign or reposition components as necessary.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

21

    • Check for collapsed, dented, or bent brake pipes.
    • Check the brake hoses for sharp kinks.

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

--

Go to Step 22

Go to Step 23

22

Reroute or replace the brake hoses or pipes as necessary. Refer to Front Brake Hose Replacement , Rear Brake Hose Replacement or Front Brake Hose Replacement .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

23

  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 24

Go to Step 25

24

  1. Install the master cylinder reservoir cover.
  2. Loosen the master cylinder mounting nuts 13 mm (0.5 in).
  3. Separate the master cylinder from the vacuum brake booster.
  4. Apply the brake pedal 3 cm (1 in).

Does the booster output rod move?

--

Go to Step 27

Go to Step 26

25

Replace the master cylinder. Refer to Master Cylinder Replacement .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

26

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

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

27

  1. Remove the master cylinder reservoir cover.
  2. Inspect the brake fluid for contamination.

Is the brake fluid contaminated?

--

Go to Step 28

Go to Step 29

28

  1. Replace all rubber brake system components. Refer to the following procedures:
  2. •  Brake Caliper Replacement in Disc Brakes
    •  Wheel Cylinder Overhaul in Drum Brakes
  3. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

29

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

Are the outlet ports restricted?

--

Go to Step 30

Go to Step 31

30

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

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

31

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

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 exist?

--

Go to Step 32

Go to Step 33

32

  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 Front Brake Hose Replacement , Rear Brake Hose Replacement or ISO Flares Replacement .
  4. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

33

Verify proper brake system operation.

Does the original condition still exist?

--

Go to Step 1

System OK