How does abs act?

I have a '98 Windstar (3.0 engine) which runs well most of the time, but after awhile a vibration in the front (I think) starts. It is not constant, but on again, off again. I have changed tires, had them balanced several times, had the front end checked and aligned. I also had the transmission checked. Nothing has helped. Could a malfunction of the ABS system possibly be the cause? The ABS light does not come on. How can it be checked?

On the abs issue I really dont think that would be the problem .If the vibration starts after hard braking where the brakes may have heated up then the issue could be with the rotors. Some times rotors heat up and can become some what flexable and cool down and be just fine. That may be hard to believe but it can happen. After a while they end up warping anyway. If the problem is happening at highway speed only then your rotors may be slightly warp and only noticed a those speeds if you have at all speeds they may be just warped. also one may be warp and not the other there for not notice as much. Looking at them really want tell you much sometimes.Just a thought. I know you said you had the front in looked at but did they pull the rotors?

I have a '98 Windstar (3.0 engine) which runs well most of the time, but after awhile a vibration in the front (I think) starts. It is not constant, but on again, off again. I have changed tires, had them balanced several times, had the front end checked and aligned. I also had the transmission checked. Nothing has helped. Could a malfunction of the ABS system possibly be the cause? The ABS light does not come on. How can it be checked?

Just wondering if this is a shimmy feeling or a Vibration that you can feel in the steering wheel or in your seat?
I get a Vibration when I come to stop. Stops when I put the van in park or Neut. Weird isnt it?? Only accures while stopped. It almosty feels like a Fan is runing under my Hiney, But isnt the fan. Any Ideas??

On the abs issue I really dont think that would be the problem .If the vibration starts after hard braking where the brakes may have heated up then the issue could be with the rotors. Some times rotors heat up and can become some what flexable and cool down and be just fine. That may be hard to believe but it can happen. After a while they end up warping anyway. If the problem is happening at highway speed only then your rotors may be slightly warp and only noticed a those speeds if you have at all speeds they may be just warped. also one may be warp and not the other there for not notice as much. Looking at them really want tell you much sometimes.Just a thought. I know you said you had the front in looked at but did they pull the rotors?
The problem does not seem to be related to the application of the brakes. I can be driving at highway speed for some time and then, for no apparent reason, the demon begins to work. The feeling is that of a rat-a-tat-tat bumping the front. I feel it in the steering, and it feels as if the tires are out of balance, but I have purchased new tires and then had them rebalanced a couple of times - all to no avail. So far, those who have worked on my car have come up empty as to the cause. The last time I had the front brakes done I know that the right rotor had to be turned, and I assume that the left one was also.

The problem does not seem to be related to the application of the brakes. I can be driving at highway speed for some time and then, for no apparent reason, the demon begins to work. The feeling is that of a rat-a-tat-tat bumping the front. I feel it in the steering, and it feels as if the tires are out of balance, but I have purchased new tires and then had them rebalanced a couple of times - all to no avail. So far, those who have worked on my car have come up empty as to the cause. The last time I had the front brakes done I know that the right rotor had to be turned, and I assume that the left one was also.


You may want to check to see if you have a broken front spring.