Hi,
I have an 98 Wimdstar with ABS and Traction control. When my wife was driving it up a friends steep driveway the traction control came on on bare asphalt and at the same time the brakes went right to the floor as if I had blown a line. I went and flushed the system out as I replaced a rotor lately. When flushing out the rear lines I got <u> very little</u> fluid volume out of the wheel cylinders into a hose connected into a clear bottle. I bled the whole system and still it was very low. I replaced the<u> master cylinder </u> and rebled and still poor volume out of the rear but the front calipers had good volume. Do I have to , beed the <u> HCU </u> or <u> cross bleed them </u> or bleed them <u> with out </u> the car running or pump <u> muliple times slowly </u> as I only did enough slowly to get no air bubbles.
If anyone could help and let me know if I haven't given enough info to figure this out.
Thanks for your time.....Wayne H. ( <a href="mailto:kjwedhunter@comcast.net"> My E-Mail address</a> )

 

Hi Wayne,
To properly bleed the system you will need a scan tool capable of opening up the HCU. Your dealer can do that for you and possibly other shops with good scan tools can.
Air gets trapped in the HCU and without opening it up with a scan tool you probably wont get it all out.
I doubt that is what caused the problem though.
Windstars are bad for cracking the exciter (or tone) rings on the front CV's. With a crack, the wheel speed sensor doesn't get a true wheel speed reading and the HCU thinks that wheel slip has occured and dumps the brakes to that wheel.
Another common problem is rust buildup and corrosion on the rear sensors. The sensors get corroded enough that the air gap between the exciter ring and the sensor gets too big and then it doesn't read right. Usually the sensor can be cleaned up and the bracket carefully bent to get the required gap which I think is around .020".