Back in late December my car got caught in a nasty snow storm and got wet & frozen for 3 days. I drove it 15 feet into the garage and parked it until the weather got above 60. During the down time I added a wonder bar and aluminum lug nuts. Tried to back it out for a cleaning a few months later and it wouldn't move. Put into gear, no e-brake, nothing. Had to get it to about 2500 rpm and something snaps loose and it moves fine. Backed it out to wash, then put away again. So we finally have a sunny weekend last week and I got for a short drive.
I hear a grinding noise that changes speed with the speed of the vehicle. Only on the front right side. I pull over and have a look, but everything looks ok. I drive home and it seems fine other than the noise. I have a hunch about a stuck caliper keeping the pad in contact with the rotor. But my laser thermometer shows it to be the same temp as the driver's side. Figured it would be hotter.... It does have a darker, dustier look to the rotor though.
What am I looking at? Rusted caliper? Clogged brake line? Something else?

 

i think what has happened is the rotor got real rusty, then after driving the rust embedded into the pads. you may need to replace the pads and clean the rotors.

 

i agree with the above post . but , calipers do not stick that often . brake hoses on the other hand do fail internally , and cause drag on one side or the other . i would recommened changing both . a good fluid flush is another good idea while you are at it . it has happened to me . good luck .