Stupid Brakes(again)

Here we go again, I posted this yesterday but I guess it got erased when they got their stuff back up so if you replied already can you do it again as I didnt get to read it before it got deleted.

I have replaced everything in my brake system but the booster, proportioning valve and lines. Now when things heat up the front right brake is "draggin" as well as the pedal feeling a lot stiffer. When it is cold everything works great and the thing actually stops very well for an XJ. I cleaed everything real well and evrything is installed correctly. Any insight on what I could be overlooking would be very helpful. Thanks in advance, you guys rock.

WILDHORSE

I don't know whether this happens much on XJ's, but a common problem on old Mercedes, among others, is inside deterioration of the rubber lines. They sort of flake off inside, and the resulting flaps often form what amounts to a one-way valve, causing uneven braking and occasional lockups. Since this seems to be one of the things you didn't replace, it might be worthwhile. In addition, if the lines are starting to crack on the outside, they may give you spongy braking even though they don't leak.