my brake sqeeks a lot. when cold its silent in front by the rear(drum) is very loud, when everything is warmed up, nothing makes noise until i brake light and long or slow braking. and at moderate barking force my brake pedal would rumble slightly. i check my pads and put brake compound on already, still happens. can someone show me specifically where to put the brake compound. pictures would help. the rumble issue, could it be due to my rotors being warped?