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 weight in the vehicle?

--

Go to Step 3

Go to Step 4

3

Remove the extra weight from the vehicle.

Does the original condition still exist?

--

Go to Step 4

Go to Hydraulic Brake Diagnostic System Check

4

Inspect the brake pedal assembly for the following:

    • Bent or misaligned components
    • Binding or interference between the pedal and the booster input rod
    • Interference with other components

Are the components misaligned or binding?

--

Go to Step 5

Go Step 6

5

Repair or replace the cause of misalignment.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

6

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 exist?

--

Go to Step 7

Go to Step 8

7

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

--

8

Inspect the brake rotors for the following:

    • Hot spots
    • Scored rotor surface

Refer to Brake Rotor Lateral Runout Check in Disc Brakes.

Do any of the above conditions exist?

--

Go to Step 9

Go to Step 10

9

  1. Refinish 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 (Refinishing) 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 the vehicle brake booster for the following:

    • Leaks
    • Damage
    • Restricted passages

Do any of the above conditions exist?

--

Go to Step 11

Go to Step 12

11

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

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

12

Inspect the vehicle for a leaking master cylinder (internal). Refer to Master Cylinder Diagnosis .

Is the master cylinder leaking?

--

Go to Step 13

Go to Step 14

13

Overhaul or replace the master cylinder. Refer to Master Cylinder Overhaul or Master Cylinder Replacement .

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

14

Check for leaking brake pipes, hoses or connections. Refer to Brake Fluid Leak .

Are any of the above components leaking?

--

Go to Step 15

Go to Step 16

15

Repair the cause of the leak.

Is the repair complete?

--

Go to Hydraulic Brake Diagnostic System Check

--

16

Check the brake pipes and hoses for the following:

    • Low fluid or no fluid output
    • Spurting of fluid while pressing the brake pedal
    • Particles suspended in the fluid.

Refer to Hydraulic Brake System Flushing .

Do any of the above conditions exist?

--

Go to Step 17

Go to Step 18

17

  1. Determine the area of the restriction. This will involve the disassembly of the individual brake lines and checking for low or no fluid output.
  2. Flush the individual brake line or hose. Refer to Hydraulic Brake System Flushing .
  3. If the restriction cannot be removed, replace the brake hose or brake pipe. Refer to 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

--

18

Verify the proper brake system operation.

Does the original condition still exist?

--

Go to Step 2

System OK