So last week my car was makin a horrible noise whenever I braked. At high speed it was a squeak and as the car slowed down it would turn into a moaning sound. The sound was only made when the brakes were applied so I figured that was my problem. After replacing all 4 sets of pads and having all rotors resurfaced, the noise was gone. That was Saturday.This morning the noise is back. There's no vibration during braking and the noise isn't present if I slow down by just downshifting. I have no idea what's going on here. Any input would be greatly appreciated.