3 L4-2.5L (2010)
Brake Rotor/Disc: Testing and Inspection
Rear - Brake (Disc) Inspection
REAR BRAKE (DISC) INSPECTION
Brake Judder Repair Hints
Description
1. Brake judder concern has the following 3 characteristics:
Steering wheel vibration
1. The steering wheel vibrates in the rotation direction. This characteristic is most noticeable when applying brakes at a vehicle speed of 100-140
km/h {62.2-86.9 mph}.
Floor vibration
1. When applying the brakes, the vehicle body shakes back and forth. The seriousness of the shaking is not influenced by vehicle speed.
Brake pedal vibration
1. When applying the brakes, a pulsating force tries to push the brake pad back. The pulsation is transmitted to the brake pedal.
2. The following are the main possible causes of brake judder:
Due to an excessive runout (side-to-side wobble) of the disc plate, the thickness of the disc plate is uneven.
1. If the runout is more than 0.05 mm {0.002 in} at the position 10 mm {0.39 in} from the disc plate edge, uneven wear occurs on the disc plate
because the pad contacts the plate unevenly.
2. If the runout is less than 0.05 mm {0.002 in}, uneven wear does not occur.
The disc plate is deformed by heat.
1. Repeated panic braking may raise the temperature in some portions of the disc plate by approx. 1,000 °C {1,832 °F}. This results in a deformed
disc plate.
Due to corrosion, the thickness and friction coefficient of the disc plate change.
1. If the vehicle is parked in damp conditions for a long time, corrosion occurs on the friction surface of the disc plate.
2. The thickness of corrosion is uneven and sometimes appears like a wave pattern, which changes the friction coefficient and causes a reaction force.
Inspection and repair procedure
