I've only seen collapsed lines and worn out calipers cause this. I've been working on the brakes of my scrambler for many weeks (only for a little time on the weekends) but am close to having them working properly...my desire to keep working brakes is very low right now.
Good luck, I hope you find something easy to fix it.
Lives in garage:
2004 Red Jeep TJ "X", big tires, suspension, stereo delete, dent in cowl.
1982 Red Jeep Scrambler, small block chevy on 35's.
"Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety." -Benjamin Franklin