Rear brake drags?

1998 vfr800fi non abs. My rear brake caliper seems to tighten up after say 5 to 6 stops. When the brakes are cool the wheel turns freely I just got finished flushing out all of the lines and bleeding in new dot 4 fluid and the problem still exists. Pads seem to be in decent shape but the way it is acting it is almost as if they expand when they get hot. when I apply the rear brake I do get good stopping power so I dont think the caliper pistons are stuck or at least not all of them. Has anyone here run into the same problem and what was the solution?

 

bent or deformed rotor, sticking or worn caliper pistons, partially clogged master cylinder port, master cylinder requiring rebuild. Just some things to think about.

 

slider pins need grease??

 

LOL or keep your foot of the pedal. or like NC says.

 

just wandering which would be the most likely component. These brake systems are kind of a bitch to work on and the thought of trial and error(bleeding them every time to see if it worked) is not a pleasent thought. The rotor is not warped, the pads compress when and how they should when the bike is cold and the pads seem to have little wear on them. There are a number of places to start, my first choice being the master cylinder or a close second being the rear caliper itself but there are also check valves and proportional valves due to the lbs and I was hoping for a good place to start.