Scotty, I have a 2001 GMC Sierra, 2WD, and after some excessive braking I get a grinding noise from the front left wheel. I've taken the caliper and rotor off to inspect and I see no scaring or unusual wear. The rotors and pads are about 2 years old. Duralast gold ceramic pads and duralast gold rotors. The pads still have great life left in them. Under light driving I have no issues at all but it seems like after the rotor heats up a little is when the noise happens. It sounds like metal on metal grinding and I can feel it in the pedal. It has been doing this for awhile now and I can't figure it out. I've also changed the wheel hub assembly and that didn't solve the issue either. I've tried describing the problem to other mechanics and they say "ohh a small pebble may have gotten stuck between the pad and rotor" well, that's just not the case. Any ideas?