I have seen pins that were frozen and caused the pads to constantly rub and warp rotors. I'd still start with checking tire balance and alignment first, also check your vacuum line to the brake booster and make sure it isn't loose or damaged.

Erik P.
Official 2GNT thread Hijacker
Some say that he's driven over more Covenant than he's shot, and that his grenades aren't where you'd expect them to be...
All we know is, He's not The Stig... But he is The Stig's Spartan cousin!