Fault assessment of brake discs
Judder caused by static spots
If a vehicle is not driven for a longer period, and especially if it is exposed to moisture and/or salt, corrosion can cause the brake pads to adhere to the disc or the area of the disc opposite the pad can corrode to such an extent as to cause severe judder. Corrosion adhesion can often be freed by releasing the clutch quickly in first gear to gently jerk the vehicle forward. If the adhesion is severe, dismantling the brake system and regrinding or replacing the brake discs may be the only remedy. If the brake pads are damaged they will have to be replaced. Slight judder after a longer time of non-use may disappear after the car has been driven for a while. If the judder is severe or does not go away by normal braking, the brake discs must be reground or replaced.