Guys i had the same problem from my 2000 3500 Dually and i even talked to some GM Tech people. My Truck did not have enough rear Brakes and was heating up the front rotors which in turn was warping them. i turned and replaced the front Rotors 6 times. The Gm Tech person told me to get a Perportion Valve for a 3500 Wrecker and lo in behold, that fixed my problems, i now have good rear brakes. If you need the Number i can probably dig it up!
