A good read:
https://centricparts.com/getmedia/bd...c-8-2018_1.pdf
I agree with Travis and the uneven transfer crowd here. 99 times out of 100 it’s going to be uneven transfer. And to appease Murphy’s Law, The other 1 out of 100 is going to be someone who extremely abused their brakes then drove thru flood waters, lol.
Buy this and clean off the uneven deposits:
https://www.amazon.com/dp/B007INTEMC...v_ov_lig_dp_it
There is a rare chance that if the car was driven a lot of miles with the uneven deposits, and the brakes were used hard to the point where the vibrations got extremely worse, that could negatively change the metallurgical properties of the iron. This change will perpetuate the uneven transfer layer. But if caught early, the rotors can be renewed to a fresh surface.
Travis mentioned washing the car and not getting the brakes dry, I agree with this also. And I also found that some wheel cleaners can remove transfer layer and cause pedal vibrations. I used to use Meguiar’s purple spray bottle wheel cleaner. I now use their wheel cleaner in the blue bottle.
The rotors on the SS 1LE and ZL1s are Brembo. I can’t say if a regular SS has Brembo rotors though.