I had my front pads and rotors replaced on my 1996 Econoline E-350 5.8L V8 Clubwagon last summer by a friend. Like most older vans the ABS light is basically always on. While driving it I noticed that the van pulls quite dramatically to the right while braking, and the brakes were hot. I brought it into a brake shop and they discovered that the left calliper was sticky and replaced both. That didn't fix the problem (although the heat went away) so I brought it back. They changed the brake lines and found that there was still uneven pressure when the brakes were applied.
After leaving the shop without the problem fixed I noticed that when first starting the van I could brake without it pulling but soon the ABS light would come on and it would pull again.
Is there any way I can test to see if the problem is the ABS (ie. test codes, reset, disabling the ABS)?
Thanks

 

Mike;

I have an '03 windstar and it has the ABS light on most of the time. In the Windstar the problem is that the controller malfunctions because of a bad solder point. There is a company that will repair all kinds of automotive electronics. I have not used them yet but I plan to do so this summer:
Automotive Scientific Inc. Your #1 Source for ECU, TCU, ABS, EBCM, Climate Control and Speedometer Repairs

I do not know if you can test it. Maybe you can shut the ABS off by pulling the fuse.

Good luck!

 

This is a troublesome problem because the service brake system (the brake pedal) is not supposed to be affected by the ABS at all. Period. Under normal (non-ABS stops), the brakes should apply evenly and smoothly and the ABS is supposed to be transparent.
In that light, have the extemely throughly checked the service brake system? Did the caliper slide pins move freely? Are the calipers and rotors both even and not cracked or frozen? If this can be ruled out (and you should really check the system VERY closely), then go into the ABS.
Start by pulling the codes. In this year ABS, I think there was an option of 2 or 4 Wheel ABS. If it's RABS only, then you have a base brake problem on the truck (that style only controls the rear wheels). If it's 4WABS, then it gets scary. If there are ANY codes in there for an isolation or outlet valve, there you go. Then HCU or control module has a problem that needs to be addressed and repaired. That may or may not solve this problem, as you could have an unrelated code and still have a valve problem.
At this point, have you gotten all the wheels off the ground and manually turned them to make sure that (with no brake pedal), they turn freely. Try it again with someone inside, then spin the tires and make sure the brakes work normally and don't hang up or do something else odd.
It is possible that this problem is in the HCU and is giving a false positive signal saying everything's ok when there really is just a phsically stuck. They are hard to diagnose because of this, but it is possible.
Good luck!

 

The rotors and calipers are functioning correctly, and we're checked over very closely by the mechanic (this mechanic also installed the new calipers, and the rotors and pads were installed by a different mechanic a few days before).
How do I get the codes from the ABS?
Is it the under dash fuse for ABS that I pull, or is there another fuse closer to the ABS unit?
I'm not sure if it is Rear of 4 wheel ABS. I'll check tonight when I can get to the vehicle.
The mechanic tried turning the wheels by hand and braking and didn't find and problems. Since there is uneven brake pressure at the end of the brake lines without the brakes attached, the mechanic suggested it was the master cylinder, but since the brakes seem to be even before the ABS light comes on, I would guess that the ABS is creating the uneven brake pressure.

 

If it's rear abs, again, none of this matters as there is some other problem. However, there is a black with orange stripe wire stuffed somewhere under the dash that gets either disconnected and grounded or just grounded, then the abs light will flash, give you the code. This wire is usually under one of the front corners under the dash, and is usually taped up to a loom or held down somewhere (if it hasn't been ripped off).
The 4 WABS has a connector under the hood that requires a special test adaptor. They had 4 digit codes that led to the problem area.

 

Check that front wheel caster angles are as close to equal, side-to-side, as possible. imp

 

Greasemark: This may be a silly question, but I thought ABS was to help in keeping the front brakes from locking up so you can maintain steering control in an emergency braking situation. Why would there only be rear ABS on a vehicle what would it benefit?

 

Kwakman:

I had rear ABS on a Ford Aerostar. As you brake the front wheels get loaded while the rear wheels get unloaded. You can see this as a dive-in on the front and a lifting motion at the rear. Therefore the rear wheels will lock up before the front wheels. When you brake while cornering the inside rear wheel is the one that locks up first and that can cause the car to spin out. Rear ABS prevents that and you keep steering control.
4WABS is even better. It will help you to stop your car on slippery surfaces. My Windstar has 4WABS and it saved me many times from colliding.

 

I see the thought process or logic of installing a rear only ABS on a vehicle that has a lighter back end such as a pickup truck, but it does make me wonder if having rear only ABS is even useful if your front tires can lock up? They way I see it, rear ABS is beneficial up until you lock your front tires in a braking situation, after that how could it be.

It would be akin to saying having half a seat belt is better then none. I'm certain it is, but up to a point, it can't possibly protect you as well as a full one. But because of misleading or omissions in the marketing from corporations, people might believe otherwise. To me 4 wheel ABS should be a manditory safety equipment on all vehicles just like seat belts are.

I'm just surprised is all even if I shouldn't be as I too owned an Aerostar back in the day. It would be interesting to know how many other manufacturers have used a rear only ABS system application in their vehicles outside of the big three.

 

It was quite common in the nineties. ABS was developed by Bosch and Daimler Benz in the eighties. In the beginning it was very expensive. Ford and GM developed their own versions and did it for about $400 per vehicle.
You are right, that full ABS is preferable to rear wheel ABS but Rear only greatly improved the safety where it was applied. Insurance companies extended a rebate for any ABS.
The Chevy Astro was also available with rear ABS. I suppose a lot of pick up trucks had rear ABS.