Chevy Astro anti lock brake light

alohanui2000

I have a 1996 Chevy Astro Van.I have been having problems with my anti lock brake light coming on for a while. I have taken it in a couple of times and they could find no problem. Then took it to another dealer and they said that the "Electro Hydrolic Control Module" needed to be replaced. After over $500 of work they said it was OK. Went to pick it up and when we got there they are now saying that it did not fix the problem and it now needs a "Isolation/Dump valve". This is going to be another $600 or more for that. I am getting worried that they are just trying things to see if it fixes the problem. I am not willing to put out over $500 a try to fix the problem.

The light is usually on but sometimes it is not. I had my brakes blead one time before and the light did not come on again for over a week.
We have also looked everywhere for information on these parts and can't seem to find anything. We have the Haynes book.

Can anyone help me. I don't know if this is really the problem and where can I find information on how to repair these parts.

Thank you

jgmilberg

Tell the dealer to check the ground wires on the ABS pump. My wife had the same problem under warranty, the dealer was stumped. The ABS did not work at all, and I got fed up with it and checked it out for myself, and bingo, it was a loose ground wire for the ABS pump. Sounds like the dealers stopped looking for the simple stuff and go right for the wallet or they just got spoiled with the computer that says what to fix.

Here is how to check for the ground. You will need a 12 volt test lamp, under $5 at the auto store or if you have a multimeter it will work to.
1 Locate the ABS pump, and the connector with ONLY 2 wires in it. Pretty large ones, one black and the other I think was red with a white stripe.

2 Disconnect the plug from the pump, ground the test light to the chassis, and turn the ignition on, not running just to the run position. Probe the red wire for power, if no power something else is wrong.
3 If power is present, take a paper clip and stick it into the ground side of the plug and bend it away from the positive terminal. Hook the ground from the test lamp to the paper clip, and probe the power side again, no light means no ground and you have just found your problem.

Does your ABS light come on when you start the van? It is supposed to to test the bulb, if not the ground is the most likely cause of the problem.

Keep us posted and good luck.

jgmilberg

I forgot to ask if you had a trailer hitch and wiring. If so make sure that the wires are not pinched, or grounding out. I had a S-10 Blazer that did that!

alohanui2000

update:
I don't have a hitch but thanks for asking.
I now know that my abs is working. Had to slam on brakes and the brakes did not fail or have any problems. Felt like I was slowly stopping though. My light was on at the time I had this close call. After slamming on brakes it went off for the rest of my drive. But was on again when I got back in the car later. My husband did check out the wires and they were good.
Thanks for all of your help