My brakes are driving me nuts!

[Pokie]

I have a 1994 Ford aerostar XLT mini van. I bought the van in 1995 with about 20K miles. It was still under factory warranty.

The van has had a problem with it's brakes from the day I bought it, I took the van into the dealership a few times explaining the problem and asking to have the brakes checked. The dealership said there was nothing wrong with the brakes and if I continued to bring the van in, they would start charging me to look at it or take it for a test drive.

The problem, when driving above 40 mph, if i coast down hill or just let off the gas to keep to speed, the brakes come on all by themselves. The brakes only come on slightly for a second or two then let off, then again a second or two later. This problem happens pretty consistantly wheather the van is driven with or without the cruise control.

When the brakes come on, the pedal does not move, the brake lights do not come on and the cruise control keeps functioning as normal. When traveling in the mountains, the front brakes will overheat to the point of smoke bellowing out of the wheel wells, even though the brakes have NOT been pressed on by the driver. When I detect the brakes have been applied (all by themselves), if I tap the brake pedal, the brakes come off, only to try to apply themselves again and again. When the brakes apply themselves, there is an autable buzzing sound and you can feel a slight pull in the steering wheel.

This situation not only causes frustration to the driver, it causes poor gas mileage, not to mention the fear of a fire.

Please help!

 

[BrooklynBay]

Welcome to this forum! Are the front wheel bearings too tight? Does it feel like the ABS system is on?

 

[Pokie]

Wheel bearings are fine, ABS is working properly as I have felt it come on in emergency or slipery conditions.

Remember, this van has had this problem since new. I bought the van with 20K mikes on it, it now has 140K on it.

The auto mechanics I have taken it too over the years say it's not possible for the van to turn on it's own brakes. If I take it in again, the mechanics just look at each other and either smile or laugh.

I really like my Aerostar, this is why I have kept it. I don't take it on long trips anymore as I just get too mad at it turning it's brakes on and off.

 

[IAmTodd]

Transmission not disengaging the torque converter?

 

[Pokie]

These are some of the suggestions I've previously gotten from other sources. I was pretty sure I had the only vehicle with this problem. I have driven other Aerostars and they did everything the same with the exception of my brake problem.

If the problem was the torque converter (I have had the transmission checked and adjusted), why would it keep switching on and off all by itself, additionally, why would the steering alter with the switching on and off and the front brakes overheat to the point of billowing smoke?

Again, I thank you for the suggestions but I guess I have a really strange problem,..... maybe it's haunted?

 

[IAmTodd]

Brake booster? Master cylinder? Vacuum line? You haven't said if you've replaced any of this. I'm voting brake booster since vacuum would spike when the throttle plate closes.

 

[Macgiobuin]

Sounds like your front calipers are hanging up. Are the pads wearing uneven, like the leading edge wearing faster than the trailing edge? That points to a caliper slider hanging up. If that is what you see, get new pads and grease the sliders real good. If they were smoking, the heat may have ruined the calipers; new ones are really cheap, and worth it.

 

[Pokie]

Calipers aren't hanging up and are still in good shape.

I haven't replaced any parts yet as money is too tight to experiment. I HAVE wondered about the booster, though. It makes sense, in my mind, that it could be the brake booster as it gets maximum vacuum on decelleration.

Do you think it would be possible to test this theory by disconnecting the vacuum hose to it, or do you think this would be too dangerous to try driving without it?

 

[peter @exp]

I think you will lose power brake and smash into some one.I had a leak in my and almost hit someone .Call a ford rep. about problem or B,B.B.

 

[IAmTodd]

Calipers aren't hanging up and are still in good shape.

I haven't replaced any parts yet as money is too tight to experiment. I HAVE wondered about the booster, though. It makes sense, in my mind, that it could be the brake booster as it gets maximum vacuum on decelleration.

Do you think it would be possible to test this theory by disconnecting the vacuum hose to it, or do you think this would be too dangerous to try driving without it?

You will not have power assist with the brakes so be prepared to stand on them if you need to. Also make sure to plug the port to the engine as it won't appreciate the unmetered air.

I think you will lose power brake and smash into some one.I had a leak in my and almost hit someone .Call a ford rep. about problem or B,B.B.

LOL, ford is really going to care about an 18 year old vehicle that has a malfunction. They should replace my Explorer if that's the case since everything has worn out on it.

 

[peter @exp]

Need my glasses or bigger screen

 

[speleopower]

That is odd and I have no idea where to start. I also own a 1987 Pontiac Fiero. The cool thing about this car is the other 2 owners of the car kept what appear to be every single service receipt and part receipt for everything done to the car since it was brand new.
When I bought the car in 2004 I noted it had an odd brake problem. I went ahead and changed the brake pads but the problem remained. It wasn't a bad issue just a small weird something wrong.
Anyway it was about a year later that I spent an afternoon organizing the huge pile of service receipts by date. I found in the receipts the car had been taken to the dealer for brake service multiple times then in later years to various autoshops again for rear brake service. At this point I was preparing to do a full brake rebuild using larger calipers and rotors.
After I replaced everything the brake problem went away. I feel your pain but the best thing maybe to replace the entire brake system.
-Scott

 

[BrooklynBay]

You said that you wanted to use larger calipers & rotors. Which vehicle did you want to interchange those parts with?