[s-cars] occasional brake light on start and sometimes difficult steering

[Tom Green]

Of course that's not it.  There's always more.  What brings your  
question here?
Thinking this is the place for straight answers?  Well, maybe, just  
ordinary folks
here.

First, you kind of get the idea of this hydraulic system?  Engine  
driven pump
provides pressurized fluid for steering rack and brake assist with an  
accumulator
to maintain some pressure for braking if the pump quits suddenly.   
Most 14 year old
systems will bleed off pressure after a day or so, not too big a deal  
if it pressurizes
quickly when you start up-that is, the light goes out before you motor  
off.  The light has
several functions described in the owners manual.  I recommend you  
don't drive with
the light on since the cause may not be clear.   Is the engine bay  
clean?  Especially
around and below the hydraulic pump, hoses, and steering rack, or is  
the frame rail
on the drivers side coated with oily crud?  And maybe a small fluid  
leak wouldn't be
noticed unless you carefully look for oily crud that is not completely  
dry?  Where this
fluid goes, the pressure goes also, so little leaks are big problems.

When you check the hydraulic fluid quantity, check its cleanliness  
also.  The fill
opening has a screen filter that lifts out.  If the screen is black,  
the fluid is probably
dark also with minute pieces of hose in suspension and on every screen  
in the system.
That requires cleaning all the screens and flushing the fluid.  The  
particles can restrict
flow from the pump giving false indications of pump failure or  
interfere with check valve
operation at the brake accumulator or booster allowing pressure to  
bleed off after shutdown.

The hydraulic system is self bleeding so don't be concerned about air  
in the system.  Since
the pump draws fluid from the bottom of the reservoir, if it draws  
air, the reservoir is empty.

Your steering problem is not related to the accumulator.  It is  
insufficient fluid at operating
pressure or internal seal failure in the rack.  Solving that problem  
may fix the others as well.
Have you seen the brake light flicker when the steering gets difficult?

You haven't mentioned any brake problems.  Is the pedal hard when you  
first start?  Indicating
no boost pressure?  If it hasn't been mentioned, you can not stop the  
car from highway speed
without boost.  You can't stop on my driveway without boost.

One of the problems with the little leaks is the cost.  This is the  
lowest cost I know of, but others
come close. Consider the total cost shipped:
http://www.discountgermanparts.com/catalog/?N=9614+4294963914+1574+7177

Tom

> -----Original message-----
> Date: Thu, 25 Jun 2009 19:44:00 -0400
> From: Jared Robinson <chapel976 at gmail.com>
> Subject: Re: [s-cars] occasional brake light on start and sometimes
> 	difficult steering
> To: "Kunz, Bob" <bob.kunz at hp.com>
> Cc: "s-car-list at audifans.com" <s-car-list at audifans.com>
> Message-ID:
> 	<454331ae0906251644l3b96570eted1adc984e57c69 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> So my potential problems:
> Air in the hydraulic system
> Hydraulic (Power Steering?) pump
> Brake Accumulator
>
> that it?