PCCB wear - Service procedure
I like to track my 991.2 Turbo S a lot (now on CUP tires) and I just love the PCCBs; this is by far the most fantastic brake I've ever owned. But because it is the brake, I'm always concerned about its proper function and I'm getting quite anal when it comes to service.
During a track day last week a Porsche guy told me, that the disks are in perfect shape, because if they were not, one would recognize the wear indicators (small black patches in the disc). But today I learned, that this is no longer the case. Current PCCB discs will not shrink significantly in diameter (like steel discs), but the heat will slowly destroy the inner of the disc. The service procedure for the current PCCBs is to get them out of the car and use electric induction testing and a laser to measure if the disc is still ok. If you are the proud owner of such a brake, you can have a look at the disc, which will tell you the min and max value that this particular tool will measure. The good news is that the technician told me, that he has never seen a broken disc.