[68c10airstream]

I fixed a friend's 2004 2500 hd for the same thing. For his safety sake I replaced all lines from the abs unit out to the wheels. Your frustration will be that the bleeders don't open up. Replace the lines as needed and gravity bleed out the air as close to the wheel as possible, then push in the caliper piston or wheel cylinder as you crack open the closest new fitting at the wheel to remove the air. Removing the box will give you the most room but if you opt to remove the tank you may get fuel leaks in the process. Box removal isn't too bad, you need 4 guys to do it comfortably.

When I replaced the lines I removed the driver's side front wheel and inner fender rubber flap and worked from there. The rf wheel took a 2 piece line to negotiate all of the turns, but not bad.

Pay attention to the cab mount where it attaches just below the driver's door hinge area. The frame has a cup welded onto the outboard side of the frame and there is a couple of grounds that screw into the back of this cup, one being the abs unit ground. Remove the bolt, scrape the frame shiny, shine up the eyelets, and shine up the bolt. Reinstall the bolt and put grease all over the bolt including the threads sticking out and forget this ground from ever getting corroded again.

Before you go to drive the truck make sure the master cylinder is at the max full line and no more!!! If you over fill the master your rotors will be blue color because there will be residual pressure on the brake system even with your foot off of the brake pedal because there is no air pocket above the brake fluid inside the master cylinder to allow room for warm fluid expansion