'87 5KCSQ brakes not releasing properly

[Ameer Antar]

Hmm...you're right something sounds amiss w/ the hydraulic system. After 
shutting down the car, how many pumps do you get before the pedal goes 
stiff? Should be 10-20 pumps. If not, you need a recharged/new bomb. Also 
check the damper hose which connects the pump to the bomb. I believe if 
this hose is damaged, it will interfere w/ building up enough pressure.

Any hydraulic leaks anywhere? Take the return line off the hydraulic fluid 
reservoir that comes from the brake servo w/ engine running. It might have 
some built up fluid in there, but once you drain it initially, there should 
only be a few drops coming out regularly. If it's more like a flow, the 
servo is bad....You might have to flush out your hydraulic system if it's 
really nasty and old.

Still though, the M/C should return itself no matter what. The servo only 
assists, but it does no braking itself. It's not in the brake circuit at 
all actually. It's just physically mounted between the pedal and m/c. 
Unless the pushrod for the servo was misadjusted, the sevo should not 
interfere w/ the m/c returning. You actually might have more than one bad 
component here. Take things slowly as you figure things out and how they 
work...no need to waste any more $$$. good luck.

-ameer


At 11:24 AM 2/1/2001 , you wrote:
>Hi Ameer,
>
>Thanx for your reply. I had been thinking M/C, but
>then had started drifting to the high pressure pump
>system; as the pedal gets quite hard when the
>situation occurs. It is a gradual building thing until
>the brakes are really dragging and then it will
>suddenly release and the boost will drop back down and
>it will start building again. It is never enough to
>lock the brakes...just really heat them up:-(
>
>Thanks again,
>
>Shef
>
>--- Ameer Antar <ameer at snet.net> wrote:
> > sounds like m/c. The spring in there may have
> > crapped out. Also check the
> > brake pedal spring. Check the distance between the
> > brake servo flange and
> > clevis hole in connecting rod end, it should be 9.8
> > in. Rebuilt m/c's are
> > cheap...new OE units are better and aren't too
> > much...around $100....at
> > least cheaper than rear calipers...[Audi says m/c's
> > can't be rebuilt].
> >
> > Also you might have some issues w/ the power brakes.
> > After you shut off the
> > car, the pedal shouldn't get hard until you've got
> > 10-20 pumps out of it.
> > The bombs often go bad and the servo can too, but no
> > power brakes just
> > requires more effort to stop the car, but the pedal
> > shouldn't go all the
> > way down or not return all the way. good luck.
> >
> > -ameer
> >
> > At 05:58 PM 1/31/2001 , you wrote:
> > >Hi fellow audinauts,
> > >
> > >It has been a few year since I last subscribed to
> > the
> > >"list". It has a whole new look. As those of you
> > who
> > >may remember me, might remember, I spend alot of
> > time
> > >out of the country and the list did then, and
> > probably
> > >still does, generate alot of posts. Hence, I
> > >unsubscribed. I am having a few problems with my
> > car.
> > >The biggest one is that during stop and go driving
> > the
> > >brakes reach a point where they refuse to release
> > all
> > >the way. It started last Summer and I thought it
> > was
> > >heat related so I had them bled...didn't help.
> > Shortly
> > >there after I replaced the rear calipers and put in
> > >stainless brake lines all the way around...didn't
> > >help. On short drives it doesn't happen; only
> > drives
> > >over 15 miles or 25 minutes. Symptoms are a very
> > hard
> > >brake pedal with alot of drag at the brakes. The
> > >fronts will get quite hot. Pumping down the
> > >"bomb/grenade" does nothing for this problem.
> > >
> > >Help!!! As my girlfriend is getting quite annoyed
> > that
> > >we away have to take her vehicle on longer trips:-)
> > >
> > >As always,
> > >          your friend,
> > >
> > >Shef
> > >
> > >__________________________________________________
> > >Get personalized email addresses from Yahoo! Mail -
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> >
>
>
>=====
>Sheffield Corey
>'87 5KCSTQ
>"Quattro: The way to GO! when the conditions say: NO!!!"
>But as a wise fellow once said: 2x0=4x0
>
>__________________________________________________
>Get personalized email addresses from Yahoo! Mail - only $35
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