Pinpoint Test A : Vibration When Brakes Are Applied
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
- 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) OPERATIONNOTE: 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 A4 - A4 CHECK THE FRONT SUSPENSION
- Check the front suspension.
Are all the suspension components in satisfactory condition?
Yes GO to A5 No REPAIR or INSTALL new components as necessary. TEST the system for normal operation. - A5 CHECK THE FRONT BRAKE DISCS
- Inspect the front brake discs. If brake disc thickness is sufficiently above the minimum disc thickness, machine the brake disc. If disc thickness is close to minimum disc thickness, 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 A6 No The concern has been repaired. - A6 CHECK THE REAR SUSPENSION
- Check the rear suspension.
- Only service rear rotors if special issues are present. Expedition/Navigator rear brakes are not sensitive to rotor-induced vibration or shudder.
Are all the suspension components in satisfactory condition?
Yes INSPECT the rear brake discs. If brake disc thickness is sufficiently above the minimum disc thickness, machine the brake disc. If disc thickness is close to minimum disc thickness, install new brake discs as necessary. REFER to: Brake Disc Machining . REFER to: Front Brake Disc . Refer to Rear BRAKE DISC No REPAIR or INSTALL new components as necessary. TEST the system for normal operation. - Check the rear suspension.