yeah, I have a 2004 2500HD and I have that problem, just when you are about to stop, under 3mph, the brakes completely let go. to say it is nerve racking is an understatement. Im about to pull the fuse on the ABS.

the problem is with the sensor that monitors wheel speed. they get rusted and mis-read; they think the wheel is locked-up and skidding.

Chevy dealer "fixed" the problem 3 monthes ago