Brake behavior

[Grant Lenahan]

this is mysterious, but i've observed other go through similar  
agony.  So at least consider and check:

1. did you bleed the ABS dry? If so you must cycle the ABS pump with  
the bleeder in place or it pumps air.

2. could you have gotten dirt in a caliper so it wont release?

3. could you have an ABS control module failure? I have no idea why  
bleeding would cause this, so its unlikely, but i did hear of it  
causing a very similar problem once

Grant
On Nov 19, 2009, at 9:47 PM, Brian K. Ullrich wrote:

> Hi all.
>
>
>
> I'm a regular poster in the V8 and 200Q20v lists, but I have a  
> question that
> is really related to a 1990 200tq 10v, and thought you guys could  
> help. A
> little background first:
>
>
>
> I have replaced everything that is rubber under the car, including  
> shocks,
> lower control arms, tie-rod ends. In doing so, we removed each wheel
> assembly in the front including the calipers, as well as the  
> calipers in the
> back. We did the brake lines and pads all around. Prior to doing  
> so, the
> brake pedal was firm, but sort of dead, meaning that the power  
> assist did
> not seem to be active. It felt like a conventional, non-powered brake
> system. But, it worked. No ABS light, and the car stopped quite well.
>
>
>
>
>
> Once we re-assembled the car, we re-pressured the lines, and then  
> bled out
> the brakes using the pressure system. They bled well (a TON of  
> fluid), but
> when we put the car on the ground, the pedal pulsed, and then went  
> straight
> to the floor, and the calipers seem to have clamped down. We can  
> still roll
> the car, but clearly the brakes are not working.
>
>
>
> I am not familiar with this braking system, so I'm in the dark, and  
> my Audi
> wrench is more familiar with B4+ cars, so this one is a mystery to  
> him as
> well. His first thought is master cylinder (not leaking), or the  
> bomb (which
> neither of us have much knowledge of, either than it exists).
>
>
>
> Does anyone have any words of wisdom here?
>
>
>
> Thanks!
>
>
>
> Brian
>
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Grant Lenahan
glenahan at vfemail.net
(201) 602-4702 mobile