Chris,
You might try asking the 4k people on Audiworld, or try Huw at
www.humanspeakers.com/audi
I have cc'd the q-list at Audifans to see if someone may be able to provide
assistance (q-listers, e-mail replies to Chris directly)
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)

> wrote in message
oups.com...
> I wish I had a spring or a lever. This is an '84. '85 to '87 used the
> spring and lever to tell suspension diving and adjust accordingly, it
> was an adjustable prop. valve. The '84 does not have this. My prop
> valve is just below the master cylinder and completely unadjustable.
> All of my brake lines are steel and seem to be in good order. I was
> looking/hoping for that fooling pressure to the rear step you mentioned
> but for an '84.
>
> My brakes do work as per new if I push the pedal 'slowly' or whatnot,
> I'm thinking when pushing fast it sense a rear leak and closes off
> pressure. I suppose I should have been saying combination valve the
> whole time instead of prop.valve.
>
> Anyway, thanks for your help,
> Chris
>
> Steve Sears wrote:
> > Chris,
> > The brake system is supposed to be a closed system, so any air in the
lines
> > or loss of pressure is a serious issue. On the proportioning valve,
it's
> > supposed to reduce the pressure to the rears when the car brakes - as
when
> > the nose dives - thus pulling on the spring which activates the valve.
In
> > order to bleed the system, IIRC, you have to fool the prop. valve into
> > thinking that the car's suspension is at rest (some of the postings on
> > Audifans mention pulling the prop valve lever to the rear of the car).
If
> > you don't trick the valve, you'll only have 20% of the brake pressure
going
> > to the rear, and 80% to the front.
> > WRT the brake system, if you're using the original lines then you're
asking
> > for trouble. Old lines can become herneated and collapsed internally
and
> > you'd never see a problem until they burst. Check the hard lines for
> > excessive corrosion as well - you can get lengths of metric bubble flare
> > tubing at your local FLAPS. The difference between slow and fast
presses of
> > the pedal sounds like brake fluid is bypassing the plunger in the master
> > cylinder. I have read postings where people have mentioned that the
seals
> > in the MC get damaged while bleeding, as they pass along areas of the
> > cylinder that they wouldn't normally (and where some corrosion may
exist)
> > when the pedal is pumped to the floor.
> > Brakes are something that should not be "mickey moused" - they're not
> > optional equipment. You need all 4 wheels to have them, not the fronts
> > only.
> > Cheers!
> > Steve Sears
> > 1987 Audi 5kTQ
> > 1980 Audi 5k
> > 1962 and '64 Auto Union DKW Junior deLuxes
> > (SPAM Blocker NOTE: Remove SHOES to reply)
> > > wrote in message
> > oups.com...
> > > Hi,
> > > I think there is air in my rear brake lines, but bleeding is a
> > > rediculous pain. I know the proportioning valve on the '84 is not
> > > adjustable, but is there a way to disable it? I know the first ones
on
> > > Jeeps there was a button that could be held. I just want a way to
keep
> > > normal pressure or lot's of pressure to the rears while bleeding.
> > > Right now I can bleed once and then the rears get closed off.
> > >
> > > My main problem is that I have either a leak or air in my lines, but I
> > > can't see a leak and don't seem to lose fluid. If I press my brake
> > > pedal slowly it goes about 3/4 or 7/8 to the floor, but still feels
> > > like a normal pedal. When it does this I get pressure to all 4
wheels,
> > > but probably about half of what I'd call normal pressure. If I push
> > > the pedal more rapidly or fast it will only go half way and feel like
a
> > > normal pedal with full pressure, but only the front wheels will have
> > > pressure. I'm hoping it's just air in the rear lines and under lots
of
> > > pressure that compressed enough to divert the flow and close off the
> > > rears. If it's something more serious then maybe there's a way I can
> > > make the fronts always have the pressure? Right now I can brake fine
> > > with the mostly depressed pedal, I'm just worried when I go to get the
> > > car inspected they will say it's inappropriate that way.
> > >
> > > Thanks for any help,
> > > Chris
> > >
>