Re: Mush when ya squish

[VINCELYONS@aol.com]

>
>   Vince,
>
>       I know you are just the parts manager, but I figure you might know
some
> stuff about the service procedures on Audis or at least could ask someone
you
> work with for me.  I have been experiencing a problem with my '87 5KTQ and
I
> have been in and out of several shops, and the problem still persists.  I
chand
> ged the pads out on my car for a set of Cool Carbons, hand sanded down the
roto
> rs (to remove any scarring) and flushed out the old (OEM) brake fluid, and
adde
> d some ATE Super Blue brake fluid (y'all probably stock this in your parts
depa
> rtment).  I just added the new fluid, and bled out the old fluid using the
conv
> entional (2 person pumping the pedal) method.  I did this till the fluid
came
> out nice and bright blue at all four ends.  Well, the brakes worked great,
but
> the pedal felt really mushy, and had a wierd pedal feel.

>      I figured there was still some air in the lines, so I bled them again,
an
>d then realized that although it got better, it was still very mushy!  I
dealt
>w\ith it for a while, and then I bled them a third time, being very careful
not
>to get any air in (and using a clear tube for the outflow to check for air
bubb
>les).  All looked good, but low and behold, the pedal feel was still really
cra
>ppy and mushy feeling!!!  I can literally push the pedal down almost halfway
>before I feel anything!  Really annoying.

Dan, 

Sorry, not familiar with the the "ATE Super Blue"... It's Audi's coins when
we use brake 
fluid most of the time thanks to the "3 Year Test Drive"...  Audi's (VOA
Autobahn) B00060012 brake fluid is DOT 4. Don't know who makes it for them.

DOT 3 has too low a boiling point and DOT 5 is silicone based that isn't
compatible with
DOT 3 or DOT 4 so it's more trouble than it's worth.

When we host the Porsche Club tech sessions most of them bring their own
fluid, but many
use the Autobahn DOT 4. Other favorites with the Porsche crowd is the Castrol
GT/LMNA the Porsche 000-043-something... or the Ford Motorsport stuff cause
it's boiling point as I recall is 600 or more or at least a lot plus some
extra.  None of that is really as important as the fact that it's new, clean,
and hasn't had a chance to suck up our SE PA humidity yet.

But about your problem...

No matter what brand pads they always seat best with new rotors ( the
crosshatch patern makes break-in less painful )  The mush might just be the
fact that the pads have not seated to your hand sanded rotors.  If they are
some sort of trick awesome never fade pads that may just be making the
break-in that much more painful.  

Way back in the dark ages when people wern't afraid to let me work on cars...
We used to road test the cars around the block with one foot holding the gas
pedal and 
the other holding the brake pedal till they glowed in the dark  proceedure
known as 
"seat in the new pads" . When the smell became really rancid you  kinda knew
you were contouring the pad to the warpage  and grooves  of the rotor, therby
eliminating the sponge pedal.  Actually,  probably not too good to submit the
rotor to that much tempering.  Time and miles ??? maybe if everything else is
good.

On any of these repetitive bleed jobs have you actually gotten any air out of
any
lines or is it just pissing a solid stream.  Pressure bleeder or
pumpit/holdit technology
doesn't matter as much as bleeding into a jar so you can see if there are
bubbles. It
is much more effecient than trying to look for bubbles as the brake fluid
irrigates your
retina. Less painful too. 

Vince Lyons