Hi,
I've had problems with this for a while, in the mean time I've been
driving my other car, but a couple years ago I replaced the disc pads
on all 4 wheels of my vehicle. I noticed the front brakes dragging
horribly and the rears seemingly getting no fluid. After some
investigation (on and off while I was at college and driving something
else), I found the brake balancer and put fluid to the rear, to
discover and broken line in the rear. I replaced this and then set
about bleeding the system.
I couldn't bleed more than a half pedal's worth to either rear tire
without the balancer tripping. I know I have no more leaks, and it's
getting harder and harder to have the balancer recenter itself. It
will not do it itself on starting like most cars, even if pressure is
restored, bleeding that valve on the proportioning valve is the only
thing I can do to get pressure to the rear and I have to bleed 3-4
pedals worth.
My current situation is all wheels seem to be dragging now, the
rears quite bad, to the point of them really needing a rest after a
mile drive. The rears still aren't connected to the brake pedal
though, upon hitting the brakes I can tell only the fronts are
stopping, I've verified this by jacking up the rears and checking with
someone hitting the brakes.

I've also read something once of a person (diff car) having their
pedal constantly depress slightly on the brake servo, causing the car
to always have the brake slightly applied. He could not figure how to
correct it and put washers under the servo to raise it out a bit and
'recenter' it that way.
Could this be related at all?

I really would like to fix this so I can drive it some,
Thanks a lot,
Chris

 

"ItJstAGame" <cjwerner@alum.rpi.edu> wrote in message
news:f0cc386a.0407221117.746e877f@posting.google.c om...
> Hi,
> I've had problems with this for a while, in the mean time I've been
> driving my other car, but a couple years ago I replaced the disc pads
> on all 4 wheels of my vehicle. I noticed the front brakes dragging
> horribly and the rears seemingly getting no fluid. After some
> investigation (on and off while I was at college and driving something
> else), I found the brake balancer and put fluid to the rear, to
> discover and broken line in the rear. I replaced this and then set
> about bleeding the system.
> I couldn't bleed more than a half pedal's worth to either rear tire
> without the balancer tripping. I know I have no more leaks, and it's
> getting harder and harder to have the balancer recenter itself. It
> will not do it itself on starting like most cars, even if pressure is
> restored, bleeding that valve on the proportioning valve is the only
> thing I can do to get pressure to the rear and I have to bleed 3-4
> pedals worth.
> My current situation is all wheels seem to be dragging now, the
> rears quite bad, to the point of them really needing a rest after a
> mile drive. The rears still aren't connected to the brake pedal
> though, upon hitting the brakes I can tell only the fronts are
> stopping, I've verified this by jacking up the rears and checking with
> someone hitting the brakes.
>
> I've also read something once of a person (diff car) having their
> pedal constantly depress slightly on the brake servo, causing the car
> to always have the brake slightly applied. He could not figure how to
> correct it and put washers under the servo to raise it out a bit and
> 'recenter' it that way.
> Could this be related at all?
>
> I really would like to fix this so I can drive it some,
> Thanks a lot,
> Chris

Park brake cable has enough slack ? That's what did it with my '87 Quattro

 

"ItJstAGame" <cjwerner@alum.rpi.edu> wrote in message
news:f0cc386a.0407221117.746e877f@posting.google.c om...
> Hi,
> I've had problems with this for a while, in the mean time I've been
> driving my other car, but a couple years ago I replaced the disc pads
> on all 4 wheels of my vehicle. I noticed the front brakes dragging
> horribly and the rears seemingly getting no fluid. After some
> investigation (on and off while I was at college and driving something
> else), I found the brake balancer and put fluid to the rear, to
> discover and broken line in the rear. I replaced this and then set
> about bleeding the system.
> I couldn't bleed more than a half pedal's worth to either rear tire
> without the balancer tripping. I know I have no more leaks, and it's
> getting harder and harder to have the balancer recenter itself. It
> will not do it itself on starting like most cars, even if pressure is
> restored, bleeding that valve on the proportioning valve is the only
> thing I can do to get pressure to the rear and I have to bleed 3-4
> pedals worth.
> My current situation is all wheels seem to be dragging now, the
> rears quite bad, to the point of them really needing a rest after a
> mile drive. The rears still aren't connected to the brake pedal
> though, upon hitting the brakes I can tell only the fronts are
> stopping, I've verified this by jacking up the rears and checking with
> someone hitting the brakes.
>
> I've also read something once of a person (diff car) having their
> pedal constantly depress slightly on the brake servo, causing the car
> to always have the brake slightly applied. He could not figure how to
> correct it and put washers under the servo to raise it out a bit and
> 'recenter' it that way.
> Could this be related at all?
>
> I really would like to fix this so I can drive it some,
> Thanks a lot,
> Chris

Park brake cable has enough slack ? That's what did it with my '87 Quattro

 

The rear brakes typically do not provide any stopping effort until you
use the brake pedal quite hard. The centering that you have been doing
might have thrown out this relationship.

Also, the brakes need to be bled with a pressure system and not by
pumping like in most other cars. This is due, in part, to the rear
parking brakes which have a threaded adjusting stud inside the rear
caliper piston. When rebuilding the rears one needs to both, push and
turn to get the piston in.

I would try to return the 'centering' to where you found it, pressure
bleed the system and then investigate what I think is your real problem
- a bad master cylinder.

The Master Cylinder typically fails by causing the brakes to drag and
lock up. This is due to overheating because the MC is located directly
behind the radiator fan and gets hot a lot.

The DIY test for this is to bring a bucket of ice water with you and
drive until the brakes grab or seize. Then get out and pour the ice
water all over the master cylinder. If this frees things up you need to
replace the master cylinder.

There is a current thread at the audiworld forum that shows a cheap and
easy pressure bleeder.

http://forums.audiworld.com/v8/

This is the type 44 forum.

Tony
'91 100q 5spd

ItJstAGame wrote:
> Hi,
> I've had problems with this for a while, in the mean time I've been
> driving my other car, but a couple years ago I replaced the disc pads
> on all 4 wheels of my vehicle. I noticed the front brakes dragging
> horribly and the rears seemingly getting no fluid. After some
> investigation (on and off while I was at college and driving something
> else), I found the brake balancer and put fluid to the rear, to
> discover and broken line in the rear. I replaced this and then set
> about bleeding the system.
> I couldn't bleed more than a half pedal's worth to either rear tire
> without the balancer tripping. I know I have no more leaks, and it's
> getting harder and harder to have the balancer recenter itself. It
> will not do it itself on starting like most cars, even if pressure is
> restored, bleeding that valve on the proportioning valve is the only
> thing I can do to get pressure to the rear and I have to bleed 3-4
> pedals worth.
> My current situation is all wheels seem to be dragging now, the
> rears quite bad, to the point of them really needing a rest after a
> mile drive. The rears still aren't connected to the brake pedal
> though, upon hitting the brakes I can tell only the fronts are
> stopping, I've verified this by jacking up the rears and checking with
> someone hitting the brakes.
>
> I've also read something once of a person (diff car) having their
> pedal constantly depress slightly on the brake servo, causing the car
> to always have the brake slightly applied. He could not figure how to
> correct it and put washers under the servo to raise it out a bit and
> 'recenter' it that way.
> Could this be related at all?
>
> I really would like to fix this so I can drive it some,
> Thanks a lot,
> Chris

 

The rear brakes typically do not provide any stopping effort until you
use the brake pedal quite hard. The centering that you have been doing
might have thrown out this relationship.

Also, the brakes need to be bled with a pressure system and not by
pumping like in most other cars. This is due, in part, to the rear
parking brakes which have a threaded adjusting stud inside the rear
caliper piston. When rebuilding the rears one needs to both, push and
turn to get the piston in.

I would try to return the 'centering' to where you found it, pressure
bleed the system and then investigate what I think is your real problem
- a bad master cylinder.

The Master Cylinder typically fails by causing the brakes to drag and
lock up. This is due to overheating because the MC is located directly
behind the radiator fan and gets hot a lot.

The DIY test for this is to bring a bucket of ice water with you and
drive until the brakes grab or seize. Then get out and pour the ice
water all over the master cylinder. If this frees things up you need to
replace the master cylinder.

There is a current thread at the audiworld forum that shows a cheap and
easy pressure bleeder.

http://forums.audiworld.com/v8/

This is the type 44 forum.

Tony
'91 100q 5spd

ItJstAGame wrote:
> Hi,
> I've had problems with this for a while, in the mean time I've been
> driving my other car, but a couple years ago I replaced the disc pads
> on all 4 wheels of my vehicle. I noticed the front brakes dragging
> horribly and the rears seemingly getting no fluid. After some
> investigation (on and off while I was at college and driving something
> else), I found the brake balancer and put fluid to the rear, to
> discover and broken line in the rear. I replaced this and then set
> about bleeding the system.
> I couldn't bleed more than a half pedal's worth to either rear tire
> without the balancer tripping. I know I have no more leaks, and it's
> getting harder and harder to have the balancer recenter itself. It
> will not do it itself on starting like most cars, even if pressure is
> restored, bleeding that valve on the proportioning valve is the only
> thing I can do to get pressure to the rear and I have to bleed 3-4
> pedals worth.
> My current situation is all wheels seem to be dragging now, the
> rears quite bad, to the point of them really needing a rest after a
> mile drive. The rears still aren't connected to the brake pedal
> though, upon hitting the brakes I can tell only the fronts are
> stopping, I've verified this by jacking up the rears and checking with
> someone hitting the brakes.
>
> I've also read something once of a person (diff car) having their
> pedal constantly depress slightly on the brake servo, causing the car
> to always have the brake slightly applied. He could not figure how to
> correct it and put washers under the servo to raise it out a bit and
> 'recenter' it that way.
> Could this be related at all?
>
> I really would like to fix this so I can drive it some,
> Thanks a lot,
> Chris