CLHR

I wonder too what happened, but I guess that is the most probable explanation Anyway, I hope insurance will cover it.

But I'm still so confused regarding the condition of the rotors at the time of the purchase. In great condition, according to the seller. Something is very wrong, according to a couple of friends. Unfortunately, I'm not knowledgeable enough to judge the condition. But the repair shop visit tomorrow will tell, of course.

CLHR

I picked up this 2018 car in March with 15 700 km (~9 800 miles) and now it has 18 100 (~11 200). Can't let this awesome thing stand around collecting dust in the garage hehe. It's just amazing to drive!

thebishman

I would suspect damage to the single rotor whilst removing/replacing the wheel, meaning someone not being careful. As for the ‘look’ of the rotors, it can be normal to get those ‘stress lines’, but it might be that yours were more highly stressed due to track usage. Did the previous owner heavily track the car? With just 40% of the pad life left when you bought the car and since it only had 9,800 miles on it, I bet it was tracked.

tjg81296

Check out sgr_automotive on Instagram. They sell a lot of takeoff's and I've seen PCCB's posted by them. Good luck.

unotaz

If your car had 15700km when you bought it and it was already down to 40% wear, then this car has been heavily used (tracked). If it was used normally with spirited driving on the canyons, it's almost impossible wear out your PCCB like that.

CLHR

You guys are right, it has definitely been tracked. But if the seller informs me that the discs are in very good shape, I still expect them to be of course

bluehorseshoe

Scoring on inner barrel of your front wheel is normal. Sadly, this is a Porsche design flaw with the larger PCCBs and standard 20" front wheels. This has happened to me on 4 different sets of wheels across three different 991GT models.

Likely unrelated to disc damage.

Perimeter

After 3 GT cars with PCCBs, I thought I was being "informed" about the close barrel distance so I bought standard brakes for the GT3 039 option.
Posts here claimed "braking was comparable" between Std and PCCB, but after owning, I could not disagree more and even had the dealer's tech drive my car 20 miles to tell me if I was wrong to think something was off.
I was wrong, std brakes simply act that way (lesser initial bite and lack of depth, yet huge six pot fronts)
so I am now installing PCCBs.

CLHR

How does the damage occur?

ipse dixit

How did the seller determine that the rotors were in "great condition"

The only way to determine the condition of Porsche PCCBs is with the use of a Carboteq tool, which measures density. If the seller had done it, they should have the density measurements of reach rotor.

qbix

you can buy new or like new for 2500-3000EUR per piece on auction portal. Send me a message and I can help you out.

usctrojanGT3

Sorry to hear what happened. Just another reason to stick with the red calipers.

rob944s2

+1. Would like to know more about this design flaw too

mwar99

Not sure I would categorize it as a design flaw. Any wheel that runs close to the caliper will have this issue. Most likely a rock got lodged between the caliper and the wheel creating the scoring of the barrel of the wheel. Given the diameter of brakes these days, unless you have 22-23 inch wheels you will have the potential for this issue.

parkerfe

I would replace all 4 rotors with steel and have the calipers power coated red.