The R/F brake caliper is binding but not enough to cause any noticeable pull or to overheat the rotors. The other three wheels spin with normal friction. To diagnose the problem I have completed the following:
1. Replace the R/F caliper with a new unit. This did not make a change and the old caliper was new this season.
2. Replaced the front rotors. I did this as part of routine maintenance as the rotors were starting to crack (4 weekends).
3. Replace all the braided steel brake lines with a new kit. It didn't make sense to change just one. Before installing the lines, I loosened the bleed screw on the R/F caliper and the wheel spun a little easier. After installing new lines and doing a full bleed of the brake system, the R/F caliper was still binding.
4. If I back off the brake caliper piston, the wheel spins freely
At this point, I am leaning towards replacing the proportioning valve (or Valve, Dual; Part #: NC10-43-900A). The master cylinder has one line connected directly to the L/F caliper. The other lines go through this valve. As the other three wheels are not having this issue, I am assuming the valve is the cause.
Am I on the right track?