Hey guys...I need some help...I was helping my friend change his pads and rotors on the front of his 2000 cougar and when we got everything finished there is a grinding noise when he applies the brakes. Please no jokes about the pads being in backwards lol. I was thinking maybe we didnt get the protective coating off of the rotor? not really sure...Also there is a high pitched squeeking coming from the back driver side wheel...any suggestions there??? I read another post about flash rusting could that be it?? not real sure. Brakes arent my thing, I would appreciate some help. Thanks