Is the front also dragging? The rear and the front, don't remember left or right, are linked together. If both are dragging the problem would be the master cylinder, if only the rear it may be the rubber hose.
Already replaced the rubber hose and rebuilt the caliper with new seals and pistons. The pedal returns all the way. Yes, the front brake drags as well. Although I took the master cylinder apart and ran a thin wire through the relief hole, it still drags. I'm pretty sure it is the master cylinder that is the issue. Didn't want to rebuild it to put it back on only to find the problem is still there. I'm tired of F*%#*ing with it! Was trying to buy a new one after market, but I guess no one sells them? May have to resort to buying a used one off from Ebay and hope for the best?