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

Verify the customer is not riding the brake pedal.

Is the operator riding the brake pedal?

--

Go to Step 3

Go to Step 4

3

Advise the customer of the proper braking procedures.

Has the customer been advised of the proper braking procedures?

--

Go to Step 19

--

4

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 5

Go to Step 6

5

Remove the extra weight from the vehicle.

Does the original condition still exist?

--

Go to Step 6

Go to Step 19

6

Inspect the brake pedal assembly for the following conditions:

    • 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 7

Go to Step 8

7

Repair or replace the cause of misalignment.

Is the repair complete?

--

Go to Step 19

--

8

Inspect the disc brake pads and brake shoe linings 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 9

Go to Step 10

9

Replace the brake linings. Refer to the appropriate procedure:

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

Is the repair complete?

--

Go to Step 19

--

10

Inspect the brake rotors for the following conditions:

    • Hot spots
    • Scored rotor surface

Refer to:

    •  Brake Rotor Thickness Variation Check in Disc Brakes
    •  Brake Rotor Lateral Runout Check in Disc Brakes
    •  Brake Rotor Tolerance in Disc Brakes

Do any of the above conditions apply?

--

Go to Step 11

Go to Step 12

11

    Important: If refinishing the brake rotor results in a thickness that is less than the thinnest (Refinishing) thickness, replace the rotor. Refer to Front Brake Rotor Replacement in Disc Brakes or Rear Brake Rotor Replacement in Disc Brakes.

  1. Inspect the thickness of the rotor. Refer to Component Specifications in Disc Brakes.
  2. Refinish the brake rotor. Refer to Component Specifications in Disc Brakes.

Is the repair complete?

Go to Step 19

--

12

Inspect the vacuum brake booster and its attaching components for the following conditions:

    • Leaks
    • Damage
    • Restricted passages

Do any of the above conditions apply?

--

Go to Vacuum Booster Diagnosis

Go to Step 13

13

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

Is the master cylinder leaking?

--

Go to Step 14

Go to Step 15

14

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

Is the repair complete?

--

Go to Step 19

--

15

Inspect the brake pipes, hoses, or connections for leaks. Refer to Brake Fluid Leak .

Are any of the above components leaking?

--

Go to Step 16

Go to Step 17

16

Repair the cause of the leak.

Is the repair complete?

--

Go to Step 19

--

17

Inspect the brake pipes and hoses for the following conditions:

    • 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 apply?

--

Go to Step 18

Go to Step 19

18

  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 pipe as necessary.
  4. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Step 19

--

19

Verify the proper brake system operation.

Does the brake system operate properly?

--

System OK

Go to Hydraulic Brake Diagnostic System Check