About 8 months ago I was driving in a rain storm and my rear brakes made this horrible resonating sound. I thought maybe the pads needed replacing so I replaced them. Well, the problem stopped for about 2 weeks then the horrible noise started again (only when I lightly apply brakes after they are heated up). I then took the rotors off and had them turned. This seemed to alleviate the problem then about 4 weeks later it started again. I am at my wits end. I thought maybe fluid may be getting on the rotor but it only occurs when I lightly apply the brakes. It seems to occur only in stop and go traffic. I thought maybe the caliper maybe functioning improperly cause it only seems to occur after the brakes heat up. Anyone have any ideas?