DEADLY Antilock Brake Operation: 2000 Windstar

I was in town, slowly pulling up behind a car at a stop light - moving maybe 1 mph and I touch the brakes and.... NOTHING.

So I push to the point where I'm going to break the pedal arm and the antilock system intervenes with the buzzing modulation and NO BRAKE ACTION!

So with 500lbs on the brake pedal, I'm coasting into the car in front of me at 1 mph. So I pull it in Park and it engages and stops me.

No repeat of the problem.

You want to talk about feeling helpless...

No codes.

Anyone else???

BEWARE!
Tom

I know the feeling but when you want to stop and it wont stop you panic.... I think?? Not sure in your case if you pump the brakes real quick then apply hard pressure it would have stopped better. The Windstar has a non intergreated ABS
system your Vac booster should have allowed easy force on the brakes with no stopping problems.. Not sure what happen in your case. Did your booster go bad. It maybe something like a vac problem to the booster. If it happen one time it will do it again..

I had forgotten to reconnect the vacuum to my brake booster the other day and I still had brakes. I was had to put all my 205 pounds on it but it stopped.

The "beginning" of a all braking events is fluid pressure from the master cylinder. Whether boosted or not, the event begins (hydraulically at least) with a pressure signal/command from the master cylinder.

I would no longer trust your master cylinder .... or your brake fluid (may be contaminated with flotsam). I would buy a new master cyl from Ford. I would flush the system with new fluid. I personally like the syn formula from Valvolene (SynPower).

After that I would go around to all wheels and do an inspection ... especially on rear drum brakes (if you have drums). Make sure all the mechanicals: springs, retainers, etc ... are up to snuff. There should be some lubricant between all sliding members... on fronts and rears. Of course, make sure the friction surfaces (pads, shoes) have good thicknesses.

I agree with the basics of the above: It isn't an ABS problem - it's something fundamental in the hydraulic brake system.

Basic questions:

- Have you checked the fluid level in the master cylinder?

- Have the brakes been bled recently - or ever?

Low fluid or air bubbles in the hydraulic brake lines should trigger a warning light - so I'm also suspicious of the brake warning light system. Does the brake warning light turn on when you first switch on the van's ignition? It should.

Not the ABS? How can you come to that conclusion?

Have you ever used ABS on glare ice?

You can put 500 lbs of pedal pressure and you basically coast along on the ice, with the ABS cycling at full cycle speed.

This is exactly what is happening but on dry pavement!

I believe there is a problem with the ABS speed cutout.

I seem to recall the ABS does not operate below a certain speed because it is difficult to tell if the wheels are skidding or not.

Since this failure occurs below this speed (I have experienced this speed because I leave my home going down a steep alley and with ice, I can tell immediately if the ABS is operating or not.), I suspect this lockout is not occurring.

Why the lockout is not occuring is a mystery because there is no ABS warning light.

Is it possible to get ABS codes and NO warning light?

______________________________


BTW, if the ABS if full cycling, then that means the master cylinder is working

I had a similar problem with a 95 Windstar. It would only happen at slow speeds and very rarely. I would apply the brakes and the ABS would come on but no real braking action. You would have to stand on the brakes to get any kind of braking. No codes and no ABS light, and it was so intermittent they never solved the problem. But it sounds like a Ford problem, because I've heard of this on another forum.

Talked to local mechanic.

He said he was very familiar with that problem.

He said it is a speed sensor starting to act up.

Very difficult to find the bad one.

Can also be dirt, metal dust accumulated on the speed sensor and/or the cog wheel.

So the first thing to do is clean up the cog and sensors.

Makes sense to me: if the sensor reports no pip, computer thinks wheel is locked so the ABS intervenes and reduces hydraulic pressure.

I missed the fact that you were on ice.

The laws of physics prevail ... there is a limit to what braking can be done when the tires make no, or little, traction. I have no experience and can't help you on this.

MrCreosote
Had the same problem on a 96 Windstar. My problem as you mentioned was a ABS sensor to far away from the exciter gear. It was a problem pulling into parking spaces. You would go real slow and want to stop and even with all my weight on the pedal it would not stop. Repaired the right front ABS sensor and it work perfect. It only occured a low speed below about 3 mph. I dont think the problem would happen above that speed. A ABS code tester would probably reveal a stored code.

96wWindstar180k:

I feel for you Brother!

I'll bet the first time it did it, it got your attention real good!

I am somewhat surprised that you can't bull your way through the ABS on the pedal - sort of like traction control.

Do you remember any gap measurements? like what it was and what you corrected it to?

Thanks
Tom

MrCreosote
My problem was that after Sears had put in a new half shaft that the exciter ring for the ABS actually hit the ABS sensor and eventually causing an ABS light to go on. It copmletley wore through the sensor. I took it back when I realized what had happened they replaced the half shaft. I had already replaced the sensor but was worried it would hit again. So I installed a washer between the sensor and its mounting point and all seemed to work for ahwile. Then the problem you were having started. At first I didnt relate it to the sensor as it had worked for a couple months. I decided to remove the washer and it works fine and it doesnt hit the exciter ring. I am not sure why it did the first time as there is no adjustment. I thought maybe the half shafts were different?