The rear disc brakes on my Omni GLH Turbo are noisy, but only when it's wet outside. They make a squeaking/groaning noise when it's wet outside and only for the first few minutes of driving. After they dry out, they stop making the noise. The noise is really loud when going in reverse and I notice it most when backing out of a parking space when it's wet outside. I don't even have to be pressing on the brakes to make the noise but if I do apply the brakes the groaning noise gets a lot louder.
The rear brakes are 11" rear vented discs from a '91 Lebaron GTC. Pads are the 911 brake pads from FWDP. Calipers are Raybestos remaned units with stainless steel pistons. I'm also using DOT 4 fluid. The rotors are fairly new as well and I haven't seen any unusual wear.
I've taken them apart and am sure they are put together right and the pads are clipped in correctly and everything is tight. Any ideas?