roadside help needed.

Brett Dikeman quattro at
Sun Oct 28 09:50:37 PDT 2007

On Oct 28, 2007, at 1:38 AM, I.S. Gall wrote:

> Car cannot be moved eitehr forward or reverse nor could it be pushed
> off the highway by hwy patrol.
> Could this be an abs computer malfunction?

No.  The ABS controller is not capable of applying brake pressure,  
only interrupting (and releasing) it.

> new ufo rotors and pads
> were just installed and the system was bled on tuesday.

It's a stuck master cylinder.  If it has never been replaced, it was  
a matter of time.  Mine released itself slowly if given a chance-  
perhaps over a minute or two of not touching the pedal.  Yours may  
take more encouragement or not release at all; could be a bit of rust  
or something is causing it to stick.

Thankfully, it is pretty easy to change out on-the-spot if you're  
stranded.  Prefill it with fluid as much as possible (ALL the  
ports!), remove the old unit (I believe it's just two bolts that hold  
it to the booster), remove the lines, and put in the new unit.  Drive  
gingerly since there's probably plenty of air in it.  Otherwise, get  
a flat-bed tow.

The master cylinder for the 200q20v is unique to the car.  It is not  
rebuildable.  It is more expensive than the cast iron MC's on the  
other type 44's (of course.) Worldpac carries it and I think has a  
decent price on it, but I can't remember for sure; do a price check  
against a wholesale dealer like Clair Parts Express.  If something  
shows up that isn't made by Ate, it is the WRONG unit.

You may be able to get the car to roll freely if you can get it to  
move about 20-30 feet; the ABS controller does a self-test of the ABS  
valve head in the first 50 feet on each engine start.  I *think* that  
may cause some residual pressure to be released.

Obviously, driving the car in this condition would be very risky.


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