Brake discs - repair
If the brake disc Conveyor T4 is scratched or its runout is slightly higher than the tolerance, then it can be sanded.
At the same time, it is necessary to maintain the minimum thickness of the disk, as well as the flatness and parallelism of its surfaces. The minimum thickness is given in the table at the beginning of the chapter. It is different for different models of VW T4. If you suspect that the disc is bent, measure its lateral runout. This can be done without removing the disc, but the brake pads must be removed to allow the disc to spin freely. Install an indicator with a suitable stand at the brake disc and place the tip of the indicator against the side surface close to the outer perimeter. Slowly turning the T4 brake disc, read the indicator. It can be considered that the disc is curved when the runout is greater than 0.1 mm.