GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC Suburban - 4WD 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake Pedal Excessive Effort

Step

Action

Value(s)

Yes

No

Tools Required

    • J 39200 DMM
    • J 35616-200 Test Light

1

Was the Hydraulic Brake Diagnostic System Check performed?

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Go to Step 2

Go to Hydraulic Brake Diagnostic System Check .

2

Inspect the brake pedal assembly for the following:

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

Are the components misaligned or binding?

--

Go to Step 3

Go to Step 4

3

Repair or replace the cause of misalignment, interference or binding.

Is the repair complete?

--

Go to Step 14

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4

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 or Brake Shoe Inspection in Drum Brakes.

Do any of the above conditions apply?

--

Go to Step 5

Go to Step 6

5

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

Is the repair complete?

--

Go to Step 14

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6

Inspect the brake rotor for the following:

    • Hot spots
    • Scored rotor surface
    • Grooved rotor surface

Do any of the above conditions apply?

--

Go to Step 7

Go to Step 8

7
  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 Component Specifications in Disc Brakes.

Go to Step 14

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8

Inspect the hydraulic brake booster for leaks. Refer to Seal Leak Diagnosis .

Is the hydraulic brake booster leaking?

--

Go to Step 9

Go to Step 10

9

Repair or replace the Hydraulic Brake Booster. Refer to Power Brake Booster Replacement .

Is the repair complete?

--

Go to Step 14

--

10

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

Are the outlet ports restricted?

--

Go to Step 11

Go to Step 12

11
  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 14

--

12

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 apply?

--

Go to Step 13

Go to Hydraulic Brake Diagnostic System Check

13
  1. Determine the area of the restriction. This will involve the disassembly of 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. Refer to Front Brake Hose Replacement or Brake Pipe Replacement .
  4. Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

Is the repair complete?

--

Go to Step 14

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14

Verify proper brake system operation.

Does the original condition still exist?

--

Go to Step 1

Go to Hydraulic Brake Diagnostic System Check