When fitting new disc brakes to your car it’s important to check lateral runout before and after the change. Excessive runout beyond manufactures tolerance will lead to excessive lateral runout. This is commonly caused because the hub behind the disc is defective or has not been sufficiently cleaned. Even the smallest debris on the hub surface when trapped between the new disc can/will cause further runout to occur.
Driving a car with excessive runout on new discs may not be noticeable initially but over a period of 4-5k miles brake pad material will be left on the disc leading to such issues which can be felt through the foot brake as judder or commonly referred to as warped discs.

In this example previous runout was acceptable and the new disk is also well within tolerance.

A Sealey disc run out kit was used to perform this diagnostic.

свернуть