Mick,
The problem with your coach is probably that it has been sitting still in storage way too much. The dragging brake will most likely be caused by one of three conditions. First and most likely is rusted/corroded caliper slides. This condition is common on coaches that are never/rarely driven, and with only 25,000 miles on an 18 year old coach, it qualifies as never/rarely driven. The next posiability is a sticking caliper piston. The last possiability is a bad brake hose that has a deteriated linning that acts like a check valve to keep the brake applied after application until the pressure slowely bleeds off.
Your coach has hydraulic brakes, and since my coaches have all had air brakes, I do not know your part numbers, but a call to BCS (Beaver Coach Sales) parts department, should give you that information or another owner may have them.
Gerald