Serious Brake/ABS Problems? Help!

[KarinaB1970]

I have a 98 Windstar with 95k. I was having problems with what I thought was the brakes, had all brakes/pads/shoes/rotors replaced. Same problem: When I first take after after first starting the vehicle bucks. If I try to use the brakes they "fail"..I guess I mean they grind/slide almost like they are NOT allowing me to stop. I easily slide through stop signs, etc. BUT if I start off fast (take right off) the bucking will quickly stop, the ABS light will come on, the trac light will come on and blink and the brakes will work fine. I will not experience this problem again while driving...will not happen again until I shut the car off completely and again take off. As soon as the 2 lights come on, the car runs and brakes fine.

Second small problem, when the car idles, it "rattles." Kind of a tin-like, high-toned sort of rattle.

Any ideas or thoughts on either of these problems? I want to sell it, but not sure how much it might cost me to fix first. The resale is obviously low for this vehicle even though it is in nice shape other than this. Thanks!

[Ian Howard]

Advancetrac works by utilising the ABS sensor's signals to determine how fast each tire is spinning. If one sensor gives a zero or weak reading, the vehicle automatically figures that it is now sliding out of control.

Advance trac will see for example.

Front right tire-300rpm
front left tire -300rpm
rear right tire - 300rpm
rear left tire - 300rpm.

Now lets adjust the right side to say 150 rpm. Now the advancetrac sees that the left side of the van is moving twice as fast as the right. Thus the vehicle assumes its in a slide to the right and will apply the left brake to adjust itself.

Advancetrac also works when you take off. If it sees your front left tire moving signifigantly faster then the front left, it will reduce engine power automatically to regain traction.

Front left - 0 rpm
front right - 350 rpm

So if the front right sensor is out of wack and sends a 350 rpm signal at stop, then engine belives that tire is spinning on ice and reduces power automatically.

my theroy is that you have a n/s wheel speed sensor (aka the ABS sensor) on your front left or right end. They are near the outboard CV Boot.

As for the rattling noise. Pretty much normal. more pronounced with the a/c or defrost on. Comes from the ac compressor clutch. Its like the ford power steering whine. It just does it.

[KarinaB1970]

Originally Posted by Ian Howard

my theroy is that you have a n/s wheel speed sensor (aka the ABS sensor) on your front left or right end. They are near the outboard CV Boot.

As for the rattling noise. Pretty much normal. more pronounced with the a/c or defrost on. Comes from the ac compressor clutch. Its like the ford power steering whine. It just does it.

Thanks, Ian! I will look into that. At least I have a starting point Do you know if this is something expensive to correct?

As for the chain-like rattle...it only started doing this a few months ago. The air doesnt seem to affect it. It is audible at idle, while accelerating from a low speed (initial take off) and when slowing down (like to take a sharp corner or to come to a stop). Guess I wont be sneaking up on anyone until I get rid of this hunk-o-junk

TY again.

[roger1219]

Had Like Problem With 1997, Cleaned Rear Abs Sensors, Fixed It!

[Flyingjackal456]

ABS sensors is most likely the culprit, hopefully it's not the ABS hydraulic Unit ($1,500 repair)

[rwk]

for the rattle, check the exhaust clamps by the converter. look under the car while it is making noise - for the abs, check the front abs sensor wires. there is a plastic clip in the wheel well that holds the wire up. if the clip breaks, the wire will fall and rub against the front drive avel exposing the wire