Interesting, I just didn't know. I didn't know there was some such pin. I have noticed that on an incline. Funny thing though, I have had two different mechanics that said not to use the parking brake, because of the rotors. One of these was a transmission specialist, and he never mentioned anything bad. I will call tomorrow though and ask. Thanks for the input. Yes I am well aware it's the heat. I understand how metal expands and contracts, but the simple fact is when the rotors are really hot clamping down on them with that parking brake causes them to warp as they cool. There's no physical way they can't, it's extra pressure on an expanded piece of metal that is contracting while it cools.