[s-cars] Upper strut mount R&R time?

[Joseph Pizzimenti]

Will do.  Thanks again, folks.  When replacing the J
hose, I am not sure if they switched the banjo bolts,
but they re-used the old ones, so I'm probably going
to put new ones in this winter...sooner rather than
later.  Will let the list know what happens and thanks
again.

Joe
--- tblack <Tblack5 at cogeco.ca> wrote:
> Charlie , You may have  the answer! I've heard that
> air in the system may
> cause the symptems that Joe is experiencing. Jack up
> the front wheels and
> turn the steering wheel lock to lock several times
> and let the list know the
> result.
> Tom Black
> ----- Original Message -----
> From: "Charlie Smith" <charlie at elektro.cmhnet.org>
> To: "Joseph Pizzimenti" <pizzoman at yahoo.com>
> Cc: "Audi S Car List" <s-car-list at audifans.com>;
> "Charlie Smith"
> <charlie at elektro.cmhnet.org>
> Sent: Monday, December 02, 2002 11:15 AM
> Subject: Re: [s-cars] Upper strut mount R&R time?
>
>
> > Earlier, Joseph Pizzimenti wrote:
> > >
> > > Okay, guys, I need you on this one as I'm
> stumped and
> > > about to bash my head into a wall.
> > >
> > > Steering:
> > > No Servo relay
> > > New rack
> > > New bomb
> > > New pump
> > > New J hose
> > > New control arms
> > > One new tie rod, other one has fresh ends
> > > H&R/Bilstein Sports
> > > ASW Camber plates
> > > Cleaned out filter in reservoir
> > > Flushed and replaced w/new Pentosin
> > > ATE Superblue in brake reservoir
> > > Big Reds w/Pagid Orange pads up front
> > > Both levels fine, but superblue is a little high
> > >
> > > Symptom:
> > > When turning the wheel, intermittently there is
> what
> > > feels like a hydraulic hiccup, i.e., steering
> will
> > > turn normally, but I will suddenly lose
> assistance for
> > > a brief sec and hear a mooing come from the
> system.
> > > Mooing also happened when I was cleaning off the
> > > rotors the other night (accelerate to 100 or so
> at 3AM
> > > on straight road and warm up pads, gets rid of
> noise
> > > somewhat from Orange Pads) and as I was coming
> under
> > > 50mph, I heard the mooing again.  Did not sound
> good.
> > > I also get it when the car is starting off and
> feel it
> > > through the steering wheel, as I do when the
> "hiccup"
> > > happens.  Please help, I don't want to break
> anything
> > > else.  Upper strut mounts, perhaps?  I'm at a
> loss
> > > here.
> > >
> > > Thanks,
> > > Joe
> > >
> >
> > Let's consider the situation for a moment.
> >
> > Since he is losing power assistance to the
> steering when this happens,
> > I think the problem is related to temporary loss
> of hydraulic pressure.
> >
> > The bomb stores pressure to preserve the power
> brakes when the engine
> > powered hydraulic pump loses pressure (like when
> the engine quits),
> > it does not provide a backup pressure source for
> the steering. [* see
> note]
> >
> > This means that even a momentary loss of pressure
> from the pump will be
> > something you will feel in the steering.  Like you
> said - suddenly lose
> > assistance for a brief sec.
> >
> > I don't know about the "mooing" sound, what's the
> list think - if the pump
> > briefly sucked air instead of pentosin would it
> make a noise?  What could
> > be blocking fluid pickup on an intermittent basis?
> >
> > If it's something like this going on, I'd think
> the worst that could
> happen
> > would be if the pressure loss were prolonged then
> he might lose power
> > assistance for the steering for the duration.
> >
> > Joe - one way to bleed all of the air out of the
> pentosin hydraulic system
> > is to cycle the steering wheel lock to lock
> several times.  If your
> repairs
> > that included replacing the pump and rack are very
> recent, maybe there's
> > still some residual air in the system.
> >
> > What do other folks think?
> >
> >     - Charlie
> >
> >
> >
> >
> >
> > [* note]
> > The bomb does not store very much fluid under high
> pressure.  The brake
> > assist unit uses very little hydraulic fluid for a
> single application,
> > thus the bomb can provide high pressure fluid for
> a number of brake
> > applications.  On the other hand, the steering
> rack uses quite a bit
> > of fluid volume when you turn the steering wheel;
> this is way more than
> > can be stored in the bomb.
> >
> > It would be interesting to see the operating
> pressures of the brake assist
> > and the steering rack.  I'll bet the rack operates
> at a lot lower pressure
> > than the brake assist.  Has anyone taken a pump
> apart to see if it's
> really
> > set up with a high pressure output (for the
> brakes) and a lower pressure
> > output for the steering?
> >
> > _______________________________________________
> > S-CAR-List mailing list
> > S-CAR-List at audifans.com
> >
> http://www.audifans.com/mailman/listinfo/s-car-list
>


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