[V8] well lets beat this brake acumulator to death again

Wed Mar 16 14:27:06 EST 2005

I am pretty sure the system works like this:

there is a speed sender on the transmission. The same one used for the speedo
and everything else. The speedo turns this senders pulse train into a voltage
proportional to speed.

There is a control box for the ServoTronic located near the steering column. It
receives this voltage and outputs a signal to the rack to vary the assist level.

Dave

Quoting bblake1055 at aol.com:

> I have had the same problem with the '91.  It is definitely a scarey feeling
> at 65 MPH.  It feels as if the steering wheel is trying to jerk back out of
> your hands.  I had the rack rebuilt and thought it had something to do with
> that, then my speed sensor was bad and thought that might be the cause.
>
> What controls the power assist to determine the amount of assist the power
> steering will have?  Speed sensor?, Trans?, ECU???
>
> Bob Blake
>
> '90 V8
> '91 V8
> '92 V8
> '93 V8
>
> -----Original Message-----
> From: dsaad at icehouse.net
> To: v8 at audifans.com
> Sent: Wed, 16 Mar 2005 08:57:11 -0700
> Subject: Re: [V8] well lets beat this brake acumulator to death again
>
>
> Well - in light of this, I will re-post my filter idea:
>
> I got a generic 3/8" inline automatic transmission filter - designed to go
> in
> the cooling line, and installed it in the rack return line of my power
> steering
> system. I did this after my original pump started to leak. It has been there
> for
> a few years now, and I have replaced it once (as routine maintenance).
>
> I have also switched over to "Chevron RYKON Premium 32" hydraulic oil and
> because I have 5 gallons of the stuff, I have been flushing the system out
> periodically. I just did it a few days ago, and the fluid now comes out
> pretty
> clear where before it was black, and the screen in the tank had a rubbery
> sludge
> on it before where now it is clean.
>
> Since doing this I had the "pump to rack line" hose go bad, but no seals are
> leaking anywhere. The car has about 140K on it.
>
> On the RYKON oil, I have not really had it in there long enough to know for
> sure
> about the long term effects, but I went through a pretty cold winter with it
> and
> I had no issues at all. The only thing I have noticed may have nothing to do
> with the oil and in fact be the reason some of you do not like the Servo
> Tronic
> racks.
> The issue is sometimes during high speed (for me) cornering I can feel what
> appears to be the assist level fluctuating during the corner. It is a little
> un-nerving because it feels like the assist comes on strong and the wheel
> gets
> real light. I don't normally drive that hard so I may have just never
> noticed
> before.
> Has anyone else noticed this rack behaviour?
>
> Dave
>
>
>
> Quoting Charles Wurts <cwurts12 at mindspring.com>:
>
> > You are jogging my memory.  I was faced with a nearly trashed front
> > seal a few weeks ago.....  The favorite local techs took care of it for
> > me in shortish order.  I was initially told that the first replacement
> > pump was bad, so another one had to be ordered.....
> >
> > Later, in a casual conversation with my favorite local guys, they
> > admitted that the "junk floating around in the system" had in fact
> > clogged and compromised the new pump.  They only realized it while
> > doing the second replacement.  So it sounds like the first replacement
> > pump was probably good, but was severely slowed by the junk.  FWIW.
> >
> > Charlie
> >
> >
> > On Mar 15, 2005, at 10:44 AM, dsaad at icehouse.net wrote:
> >
> > > WAG O THE DAY:
> > >
> > > I can't quite imagine how the brake section could fail completly - but
> > > as I
> > > recall, this is a plunger type pump - so maybe one of the poppet
> > > valves under
> > > the X caps is stuck open? If this is true then either some junk is
> > > floating
> > > around in the system and got stuck in the valve or the valve just
> > > failed.
> > > Neither seems likely to me but the thing to do is pull the pump and
> > > tear it
> > > down. What you find there will dictate the next step.
> > >
> > > If a line is plugged, it would have to be a serious plug. I think this
> > > pump
> > > makes around 3000 to 5000 PSI.
> > >
> > > What about the brake servo? How does that work?
> > >
> > >
> > > Dave
> > >
> > >
> > > Quoting R Broberg <rbroberg at wi.rr.com>:
> > >
> > >> My recollection is that the pump provides two separate services. One
> > >> higher
> > >> pressure than the other, for brakes and steering.  Presumably, one
> > >> can fail
> > >> without the other.
> > >> Roland
> > >>
> > >> Roland Broberg
> > >> Broberg Engineering-BECO
> > >> Delafield. Wisconsin USA
> > >> ----- Original Message -----
> > >> From: "Kneale Brownson" <knotnook at traverse.com>
> > >> To: <readytow at earthlink.net>; <v8 at audifans.com>
> > >> Sent: Monday, March 14, 2005 4:25 AM
> > >> Subject: Re: [V8] well lets beat this brake acumulator to death again
> > >>
> > >>
> > >>> Sounds like either the pump's internal plumbing or the hose to the
> > >>> accumulator is plugged somehow.  You might check the banjo bolt for
> > >>> the
> > >>> bomb hose to see if it has a screen plugged.
> > >>>
> > >>> At 07:09 PM 3/13/2005 -0800, kevin kyzar wrote:
> > >>>> to all who answered, thank you. in respones to your questions, the
> > >>>> power
> > >>>> steering works fine, the vehicle had been idled w/o the belt
> > >>>> installed.
> > >> but
> > >>>> the belt is now installed.  i pulled the "X" plugs on the front of
> > >>>> the
> > >> pump
> > >>>> and verified the eccentrics in the pump are moving.  but still
> > >>>> nothing on
> > >>>> the brakes.  and with the belt installed, and the motor idling, no
> > >>>> fluid
> > >>>> from the pump to the bomb.  I'm stumped!
> > >>>
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