OK have this brake noise, sounds like a moaning when I apply light pedal pressure, coming from driver side rear disc. I've changed pad, rotor and caliper, noise is different but still there. Took it to two mechanics and they couldn't find the problem. The inner pad has dust built up on it so I suspect it. I use disc brake quiet on the backs of the pads and that works for about 100 mi or so. All the lube points are clean and lubed. I wonder if it might be that that caliper has a hard line going to it? All the other hoses are rubber to the calipers, but this one is hard line all the way, maybe causeing it to not realease properly? Any kind of suggestions at all are welcome. I can't pick up girls if the car makes funny noises!