Subject: rebuilt high pressure hose to rack growl

[Konstantin Bogach]

Is it common to fight resonance in hydrolic systems?  In general, there is
everything for it: periodicity, boundaries, source, media.  I even had some
thoughts about it when I found that they put restrictor not exactly in same
place as original hose.
Damn!  Not again!

Konstantin Bogach.

Arun Rao wrote:

> It turns out that even the dealers (Carlsen Audi in Palo Alto in my
> case) sell two kinds of "OEM" hoses.  The cheaper (apparently
> aftermarket) one growls, the more expensive one doesn't. Trust Audi to
> make a hydraulic hose a tuned cavity (or maybe it's common practice): as I
> understand it, if any of the components in the system isn't quite right
> (hose material, restrictor diameter), you get nice standing waves in the
> hose and consequent growling.
>
> There you have it :(
>
> -Arun
>
> On Wed, 20 Feb 2002, Christopher Ritchie wrote:
>
> > Konstantin Bogach wrote (in part):
> >
> > rebuilt hose to steering rack growls from very beginning. I
> > came
> > across reports about this problem but other posts did not have
> > such
> > complains.  Because it seems so simple - hose + restrictor, I
> > decided to
> > go for it.
> >
> > Any idea why it growls?
> > ***********************
> >
> > No idea.  But mine has been doing the same thing now for over 1 year.  No
> > problem with old hose and old rack.  When rack replaced (with Jorgen), new
> > OEM hose installed.  Started growling immediately thereafter.  Moderate at
> > first.  Now hardly noticeable.  Seems to diminish with use.
> >
> >
> >
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>
> --
> Arun Rao
> Pixar Animation Studios
> 1200 Park Ave
> Emeryville, CA 94608
> (510) 752-3526