i have a 95 2500 4x4 the other day i was driving and hit the brakes and the pedal went straight to the floor abs light and parking brake light came on. they brake a little but you need about a mile to come to a stop at 55mph. i had the same problem about a year ago i changed everything on the brakes front and rear with no results (calipers,bleeding, pads, shoes and rotors). i finally had it towed in to a brake shop and they said it was some kind of valve in the abs. i was just wondering if anyone else has had this problem.

 

Had that problem on my truck at work , 94 4x4 , auto, hit that brakes doin about 60 , and it went right to the floor, i got it slowed down enough to get off the highway
and the pedal came back up after i pumped it a few times , and it has been fine since. although the next day i noticed all the wheels didn't brake evenly , especially the driver side rear , it would lock just barely touching the pedal.

 

I to have a 95 4x4 also. After looking at the system I thought that I could by pass the rear only anti locking system. Several years ago I chatted with a guy who I think is an engineer for Raybestos brakes and if I have this right he told me that when the system, antilocking, fails they swap over to standard system. My system failed after a few months of ownership of the truck, so after chatting with the fellow I just pulled the lamp have not given it any more thought. How ever I have installed one ton chev rear cylinders and have yet to lockup the rear brakes. So I have decided that I may have to find out why the pressure is not as good as I would like.
A year ago I noticed that the vaccume hose had collapsed so I changed the line to 1/2 ss tubing. The system or brakes is still pitifull as far as I am concerned. JimK

 

I had the same problem with my 2001. I have 160k miles so I figured I would change the calipers and brakes Saturday. It did pretty good but the brake light and ABS would not go off. So, my father came up with the idea of the master cylinder not giving off enough pressure and the fluid being stuck at the calipers. Well that was in fact the problem solver. I picked up a master cylinder for 54.99 at Orielly's Auto Parts at about 4:15 pm today and at around 5:00 pm everything was finshed. I, along with my dad, put the new one on drained the resovoir and bled the brakes in 45 mintues. The resovoir is reuseable just slide the little pins out and it pulls right out. As far as braking hell I stopped on a dime behind a car shortly after finishing to scare my dad and the truck stopped like a little geo metro. And Mind you guys I have a 2001 so it still has drums in the back. So with a new master cylinder, Wagner Thermo quiet pads up front, new brake shoes, and 30MM wheel cylinders in the back I think I am cooking and the stopping power is rediculous. I reset my computer by disconnecting my batteries for a couple of hours but haven't driven My truck tonight so I don't know if the ABS and brake light have gone away I will report with it tomorrow. Take Care