Hi, I have a 87 FLHTC 50k miles, my rear caliper started dragging to the point it was slowing down my speed. But it would seem to do this after going for about 5 miles,even on interstate where I would not be using the brake at all. So I cleaned the caliper good but still had the same problem, So I got a rebuild kit and new pads from HD (with new pistton) and did that. Still have the same problem. That narrows down Master Cyc. or Brake lines. My question is what which should I do first?