Rear passenger caliper keeps seizing?

The hose was the best suspect if that brake is staying on and the wheel gets real hot. Next time this happens, stop on a slight incline, place a block about a foot downhill from a tire, shift to neutral, then use a flare-nut wrench to loosen the two steel lines at the master cylinder. If loosening one of them allows the trapped pressurized brake fluid to release, suspect brake fluid contaminated with a petroleum product.