something to consider. All brakes will have a way for the fluid to return to the reservoir. On old gold wings we call it a spoog hole. These can be blocked by really small pieces of junk even if the fluid looks clear. If blocked the warming of the fluid will cause a pressure build up and the brakes will drag. This can lead to over heating of the brake fluid.
I had this happen on the front brakes of my '78 wing and also in the hydraulic clutch on our 86 1200 wing. In the first case the brake dragged. In the second case, the pressure build up disengaged the clutch.
