piper lance-------> squeeky brakes

[Dan]

The other day, i had a guy ask me why his brakes squeek. So obviously i looked to see if his pucks were worn badly, down to the steel, but to my suprise the had well over the recomended .100" thickness. So why did they squeek??? Well tuns out that they have done this ever since he had new tires put on, so i am suspecting that during the change-over, some oil or grease got on the pucks contaminating them and grazing them over, possibly causing the squeek.
Im just guessing, so i would like to know if anyone has a better idea.