Vibration When Brakes Are Applied
- A1 ROAD TEST THE VEHICLE - LIGHT BRAKING
- Road test the vehicle. Warm the brakes by slowing the vehicle from 80 to 32 km/h (50 to 20 mph) using light brake force. At highway speeds of 89-97 km/h (55-60 mph), apply the brake using light pedal force.
Is there a vibration/shudder felt in the steering wheel, seat or brake pedal?
- Yes : GO to A4
- No : GO to A2
- A2 ROAD TEST THE VEHICLE - MODERATE TO HEAVY BRAKING
- Road test the vehicle. At highway speeds of 89-97 km/h (55-60 mph), apply the brake using a moderate to heavy pedal force.
Is there a vibration/shudder?
- Yes : GO to A3
- No : The concern is not present at this time.
- A3 CHECK ABS (ANTI-LOCK BRAKE SYSTEM) OPERATION NOTE: During moderate to heavy braking, noise from the Hydraulic Control Unit (HCU) and pulsation in the brake pedal can be observed. Pedal pulsation coupled with noise during heavy braking or on loose gravel, bumps, wet or snowy surfaces is acceptable and indicates correct operation of the ABS . Pedal pulsation or steering wheel nibble with the frequency proportional to vehicle speed indicates a concern with a brake or suspension component.
- Road test the vehicle and apply the brakes on a dry, firm surface, then apply the brakes on a wet, snowy or loose surface (such as gravel).
Is the vibration/shudder only present on a wet, snowy or loose surface?
- Yes : This is a normal operating condition of the ABS.
- No : GO to A5
- A4 ISOLATE BRAKE VIBRATION NOTE: This test step is not applicable to vehicles with drum-in-hat type or electronic parking brakes. For vehicles with drum-in-hat or electronic parking brakes, proceed to the next test step. For all other vehicles, apply the parking brake to identify if the problem is in the front or rear brake.
- Apply the parking brake to identify if the problem is in the front or rear brake. At highway speeds of 89-97 km/h (55-60 mph), lightly apply the parking brake until the vehicle slows down. Release the parking brake immediately after the test.
Is there a vibration/shudder?
- Yes : GO to A7
- No : GO to A5
- A5 CHECK THE FRONT SUSPENSION
- Check the front suspension.
Are all the suspension components in satisfactory condition?
- Yes : GO to A6
- No : REPAIR or INSTALL new components as necessary. TEST the system for normal operation.
- A6 CHECK THE FRONT BRAKE DISCS
- Inspect the front brake discs.
REFER to: BRAKE SYSTEM INSPECTION .
MACHINE or INSTALL new brake discs as necessary. REFER to: BRAKE DISC MACHINING .
REFER to: BRAKE DISC .
- Road test the vehicle.
Is the vibration/shudder present?
- Yes : GO to A7
- No : The concern has been repaired.
- Inspect the front brake discs.
- A7 CHECK THE REAR SUSPENSION
- Check the rear suspension.
Are all the suspension components in satisfactory condition?
- Yes
: INSPECT the rear brake discs.
REFER to: BRAKE SYSTEM INSPECTION .
MACHINE or INSTALL new brake discs as necessary. REFER to: BRAKE DISC MACHINING . REFER to: BRAKE DISC .
- No : REPAIR or INSTALL new components as necessary. TEST the system for normal operation.