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ABS and brake warning stay lit

Posted: Mon Oct 06, 2008 5:02 pm
by Kabey's Van
I've got a '91 Astro shorty with ABS, I bought this van a couple of weeks ago.
It just had a 4 wheel brake job prior to me purchasing it.
The ABS and brake light will stay on all the time, they don't flash or dim or anything like that they just stay fully lit when the ignition is in the run position. The brake lines, reservoir, master cylinder, back side of the rear wheels and front calipers show no signs of leakage. The pedal feels good, has a little more travel than I'm used to but it has a nice feel to it.
My park brake pedal switch is being activated by the pedal and the switch works. I've checked it with an ohm meter.
Did the brake shop not reset something, as these lights could have been triggered because of the need for new brakes in the first place? Is there somthing I can unplug to reset them or maybe disconnect the battery. Will I finally have to break down and buy a code reader.
I'm sure it's a simple fix I just can't figure it out.
I miss my old Hot rod :(

Re: ABS and brake warning stay lit

Posted: Tue Oct 07, 2008 9:42 am
by remark123
ABS Light and Brake light on - means that something is wrong with the ABS circuit. It is quite possible that when the brake work was done, either one of two things happened. ABS sensor wire was left unplugged, or ABS sensor wire was broken. Either failure would be indicated by the illuminated warning lites. Other possibilities include reluctor ring corrosion, (search the forum for the fixes), or ABS sensor failure. Hope this helps. :bounce:

Re: ABS and brake warning stay lit

Posted: Tue Oct 07, 2008 12:44 pm
by Kabey's Van
Hey Remark,
Thanks for the info, if I get a chance today I'll take a look and let you know what it was.
I have an uncle that lives in Lexington, I believe thats not that far from you.
Thanks,
Peter

Re: ABS and brake warning stay lit

Posted: Tue Oct 07, 2008 12:57 pm
by GEJ
I would like to add there are a number of guys on this site that have figured out how to bypass the ABS system.The main reason has been was the ABS kicked in when it wasn't expected and they ended up hitting things.I am certain that I like the brakes on Ole Yellar over the brakes on the LT.The Ole Yellar brakes hands down just work better-no horsing around.

Re: ABS and brake warning stay lit

Posted: Tue Oct 07, 2008 2:02 pm
by kc5gxl
Just out of curiosity, are the tires all the same size? Different size tires can, and will set the ABS light. How about the parking brake? Is it all the way released, and the parking brake warning light switch adjusted properly?

Did the brake job entail rebuilding calipers or wheel cylinders? It is possible that the brake warning light plunger is offcenter, and needs to be reset. It is on the combination valve.

About both the lights being on, I kind of thought that if both red and amber lights were on, it was the regular brake system, and if it was the ABS system, then only the amber light would be lit. Maybe I have that wrong, but don't think I do.

Good luck, and let us know what you find.

Dan Harriman
Orange, Texas

Re: ABS and brake warning stay lit

Posted: Tue Oct 07, 2008 6:26 pm
by Spike99
.

I have a 2001 Safari AWD and always had problems with its brakes. Master Cylinder replacement, multiple front brake rotor replacements and over sensitive / broken speed sensors. One front wheel sensor blew and soon after, its other front wheel sensor blew. After almost hitting someone 3 times, I pulled its ABS fuse. Its ABS orange and red dash light was then covered with a few small chunks of black tape. No kidding. Since pulling its ABS fuse, my van's brakes have never been better. Its ABS doesn't come on when it doesn't need to and when I need it to stop, I simply hit its brake peddle. My van stops - like it should. For me, pulling its ABS fuse works great. Going forward, I now understand why one some brands / models of vehicles, the ABS system is now "optional" - like the Saturn ION 2 vehicle.

Now... If only I could pull its little bulbs behind its dash - to make its ABS orange light and other red light go off. Then, I could remove its black tape and contine to drive like "good old 70's vehicle" (before complex and `over sensitive` ABS electronics was every dreamed of).

Hope this helps as well...

.

Re: ABS and brake warning stay lit

Posted: Tue Oct 07, 2008 9:39 pm
by Kabey's Van
I took it for a rip and piled on the binders and the ABS did not kick in. All four wheels locked up and left fairly even skid marks but no ABS.
Brakes 1, ABS 0.
All the tires are the same size.
Calipers are new and the wheel cylinders were rebuilt.
The E-brake pedal engages with the E-brake warning light switch and, the switch itself, works.
I checked it with an ohm meter.
I don't want to disable the ABS.
I've looked over everywhere where you can see and everthing looks OK.
There's no visible leaks.
The brake lines look like they may only be a few years old.
Judging buy what shape the rest of its in and the 18 years of dealership service records that came with it, I'm thinking it's an electrical problem.
This thing is like new, for an eighteen year old van you would not believe the shape this things' in.
It has shiny parts under there and the floor boards look awesome.
Dan does bring up a good question in that how inter-connected are these two lights.
If the ABS screws up could that trip off the brake warning light, and vis-versa, if there's a problem with the brakes could that cause the ABS light to trip on.
But what is this warning light, plunger thingy you speak of and how do you reset it?
Peter

Re: ABS and brake warning stay lit

Posted: Tue Oct 07, 2008 10:41 pm
by CaptSquid
Humor me on this one. Try disconnecting the battery for about 1 minute to reset the system. It may or may not work, but it wouldn't hurt.

Re: ABS and brake warning stay lit

Posted: Wed Oct 08, 2008 5:53 am
by kc5gxl
Kabey's Van wrote:I took it for a rip and piled on the binders and the ABS did not kick in. All four wheels locked up and left fairly even skid marks but no ABS.
Brakes 1, ABS 0.
big snip.....

But what is this warning light, plunger thingy you speak of and how do you reset it?
Peter
Howdy;

If the brakes locked up, and all skidded the same, the ABS is not working. Like you, I presume that the prob is electrical. Probably a wheel speed sensor that is out of position or disconnected.

As for the warning light thingy, the front and rear brakes are on separate systems, but are activated by one dual cylinder master cylinder. If one of the systems has a pressure failure, a warning light will come on to let the driver know something is wrong. It does this by a plunger that is common to both systems, and is centered by mostly equal pressures in both. If pressure is lost in one system, then the pressure in the other will move the plunger to the side with the low pressure, grounding a switch to light the light.

This switch is located in the combination valve, along with the proportioning valve. I will check on my 91 Safari today at work and see where it is located.

Drive safely,

Dan Harriman

Re: ABS and brake warning stay lit

Posted: Thu Oct 09, 2008 6:27 pm
by v8famvan
Peter,

There is method of retrieving the codes from the vehicle without a scan tool. Check this thread out by blk lt awd, ABS dummy light on problem and diagnostic method from the TRANSMISSION/REAREND/BRAKES/STEERING section of the forum.