My left rear brake was dragging because every time I got out of the car I smelled burning brakes and there was a bunch of brake dust on the wheel. I got that fixed (stuck caliper) but I'm sure that it was on its way to your problem if I hadn't gotten that taken care of...

 

I dont know but my car doesn't have a rear brake and i didn't really smell and anything burning. but o well haven't heard from it again since then.