It's always something
 

Wife and I were riding on the interstate today, she on her '89 Custom Softail, me on the Ultra. We got off on exit ramp and she said the bike felt sluggish, like it didn't want to go. Pulled into a gas stations and after some snooping around, it appears the rear brake caliper was siezing up on the rotor. The rotor got so hot it turned blue. You can actually see that it warped out and was rubbing against the rear brake bracket that holds the caliper on. We had to leave the bike at a Waffle house and fetch the truck and trailer. I haven't taken things apart yet, but it appears I'm gonna need a new rotor and rear caliper at the least. Anyone ever have this happen, and do you think my rear wheel bearings should be replaced also, due to the heat factor???

Master cyl went. Mine did that and I had to rebuild the Master cyl. Rebuild kit is fairly cheap. I don't know about the bearings. Since you will have the wheel off at least look at them and repack them with grease.

mine started to bind up on my 85 because the caliper pistons had burs on them and they wouldn't retract back into the caliper. 2 new pistons and some brake fluid and i was back in business. i used the same caliper, just new pistons.