GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

DEFINITION: Fluctuation or pulsation is felt through the brake pedal, steering wheel, seat, floor, and/or in the vehicle ONLY when braking.

1

Were you sent here from the Hydraulic Brake Symptom table?

Go to Step 2

Go to Diagnostic Starting Point - Hydraulic Brakes

2

  1. Inspect the disc brake system for the following conditions.
  2. • Excessive thickness variation of rotor friction surfaces
    • Excessive assembled lateral runout (LRO) of rotor friction surfaces
    • Hard spots, heat checks, bluing discoloration of rotor friction surfaces; possibly due to brake drag
    • Excessive corrosion of rotor friction surfaces; including red, gray or black oxidation
    • Loose, damaged or missing caliper or lining hardware
    • Bent or damaged caliper or mounting component
    • Excessive LRO of wheel hub/axle flange; due to damage and/or loose or excessively worn bearings
  3. Adjust, repair or replace components as necessary. Refer to Disc Brake System Diagnosis.

Did you find and correct a condition?

Go to Step 3

Go to Diagnostic Starting Point - Hydraulic Brakes

3

  1. Install or connect components that were removed or disconnected during diagnosis.
  2. Road test the vehicle in order to confirm proper operation. Refer to Brake System Vehicle Road Test.

Is the condition still present?

Go to Step 2

System OK