ABS problems

Yeah, it's a bit of a mess. I just converted the PCM to the express van PCM due to a lot of problems like I posted above. I've learned a lot about what was done wrong with the V8 was dropped into this van.

Hopefully I'll have it sorted out shortly. Lots of incompatibility between years such as the computer and the transmission that was in there, then the new computer doesn't like the old O2 sensors because of the way they are grounded. Not exactly something to tackle in a format like this one. I've got threads going on in multiple tuner sites, but I appreciate the response.

Actually, it fits in there pretty well!

My Astro's brakes have an odd, but intermittent problem. Occasionally when I try to stop, they will make a groaning sound and I can feel the pedal push back against my foot and the van doesn't want to stop. If I continue to push on the pedal, you can hear a thump and then the van will stop short. A couple of times when this has happened, the pedal went all the way to the floor, the brakes released and the van started forward more quickly as the idle speed kicked in. I've replaced the pads, rotors and calipers as well as bled the lines. Do I need a new master cylinder or sensors, or what?

Ok, based on the reply, I suspect a faulty brake booster. I've looked over the diagram and pictures and feel pretty confident about replacing it. I've priced Astro brake boosters online and they're about $275. Is there a way I can test the one I have and make sure that's what I need before I put out the cash?

I put on the new booster, and the power steering works better than it has since I bought the van, but now the brake pedal goes all th way to the floor and won't come back up.
I had to take out the master cylinder to get the old booster out and the new one in, so I assume the lines need bled, which I'm going to do in the morning, but the pedal to the floor and not coming up concerns me. Is there anything else I should be looking at?

I tried bleeding the booster and the brake lines (used your instructions and instructions in Chilton manual) and I have the same problem. Did I get a bad booster?

Took the new boost off and put the old one back on and the pedal is acting normally again. The groaning problem is still there, so it's back to the store for a little exchange action. Thanks again for all your help.

I finally got the scanner and found the right front wheel speed sensor was out got a new one for $89.00 all fixed! I love this site.

Why does my ABS keep slipping when I apply the brakes? The ABS light does not come on.

What I mean is that when I apply the brakes it doesn't come to a complete stop. Instead the car still will roll. If you stop far enough in advance then you can pump the brakes a couple of times and then It will stop.

No, the brakes were checked and said that there was still a few months worth of pad left. They mentioned about taking the rotor apart and checking the gear