Caution with FrenKit caliper repair kit
 

A word of caution for the repair kit from FrenKit, item 242924. The kit is for the D3 twin pot front calipers on A8's with 360mm and 385mm discs, so V8's W12 and S8 with steels. Kit contains all the rubber and two new pistons. The pistons are to be cautious of. They are manufactured from a different metal and are almost 3 times the weight of the original ATE pistons. When doing a dry fit in a cleaned caliper they don't move smooth like the originals do. I should have taken the above as warning because when I did the caliper rebuild one FrenKit piston got fully stuck in the caliper. I "only" have 100psi on the bench and it wasn't enough to free it. I had spare caliper so I could continue and I decided to reused all the original ATE pistons.