Brake disc treatment (Audi 100 C4)

Brake discs can be reground if necessary to make them ready for use again. You also need to pay attention to the flatness of the brake disc, i.e. when reground, it must be ground so that both sides of the disc are parallel to each other.

If it is assumed that the brake disc is damaged, it can be checked in the installed state using a dial indicator for the presence of runout on the outer edge. To do this, screw the brake disc tightly, install the dial indicator pin on the outer edge and slowly turn the disc.

(A link to the original source is available on the website AudiManual)