[s-cars] re: Power steering pump

[Brian Powell]

Actually, the part number for a rebuild kit is: #035 198 049A

I recently rebuilt the PS pump on my 20v (they are the same as the S6
with different pulley).  It was alright, I didn't get a good seal on
the front half and had to take it out again.  Also, I highly recommend
a good quality (I used Lucas) pump seal/restorer.  I had some rack
problems along with the weeping pump (before rebuild) and after a few
hundred miles with it in there, the system is like it was years ago...

Here is a message on the procedure from Richard Hoffman on the 20v list:

> The kit is indeed a kit of seals.  If you aren't noticing any noise and
> didn't run the pump dry, then there will be no wear on any of the metal
> parts. Should cost $45-$60. I did the disassembly in my metal drain
> pan as
> the pump is full of hydraulic fluid and this saved extensive bench
> clean-up
> :)
> Just so you know, the S6 PS pump uses the same rebuild kit and the
> internals
> are identical to the CQ pump.  The difference is in the mounting, the
> pulley, and the hose connections.
> It helps to loosen the front/center section of the core support just
> to get
> a little more room to work on the pump.  Removal is straight-forward -
> loosen the mounting bolts, then it has a tensioner. The belt is a
> tight fit
> between the shroud and pulley.  The fittings are 19, 22, and 25mm for
> the
> hoses (if I remember correctly)
>
> Once you've got it out, the pulley should come off first.  I jammed a
> screwdriver through the pulley holes and used the appropriate allen
> wrench
> (5 or 6mm) and it was no problem.
>
> Now you can take off the big mounting bracket/shroud.  3 10mm bolts
>
> Now comes the messy part.  I believe there are 4 10mm bolts holding the
> whole thing together.  Pull apart the front section with the X-plugs
> first.
> Pull gently and gradually.  Inside this section, you can see a brass
> ring
> and see the pistons as they are driven by the eccentric lobe.  Try to
> keep
> the ring in there, its somewhat hard to put back.  I cleaned
> everything out
> with spray carb cleaner.
>
> At this point, position the pump so that the surface you just exposed
> points
> up.  The center piece can be lifted upwards but is held on by 4
> additional
> bolts.  You'll notice a large round O-Ring here and inside you will
> find the
> RSFH.  That is, the rubber seal from hell.  It's shaped like a big
> malformed
> letter H and has a nylong support.  It sits in a rather odd piece of
> aluminum. This is where it gets a little fuzzy for me.  The important
> thing
> is that you note the orientation of the aluminum piece with respect to
> the
> center section.  These parts can all be cleaned in carb cleaner dip or
> with
> the spray.  Brake cleaner also works but smells worse.
>
> The very bottom section now contains the vane pump for the power
> steering.
> The vanes can be pulled out and cleaned but you must put them back in
> the
> correct orientation.  They can only go in 2 ways and one of them is
> right :)
> Basically they must sit flush with the top and bottom surfaces of the
> vane
> carrier.  They look square but are in fact rectangular. It's easy
> enough to
> tell which is correct.  If you put them in incorrectly, you will
> destroy the
> pump.  Just take your time, make sure its good and clean, and inspect
> everything very closely.
>
> Reassembly is easy.  The RSFH and its support go in fairly easily.
> Put just
> a drop of pentosin on the seals and smear it around.  This helps keep
> them
> soft and keeps them from perma-bonding to the sides of the pump. The
> large
> o-ring has to be stretched into its little groove as you tighten the
> pump
> down.  Then, when re-installed, fill the fittings with pentosin and
> turn it
> a few times by hand to get the pump "primed"
>
> To purge the system and ensure it is fully bled, turn the steering
> wheel
> lock-to-lock a few times with the motor shut off.  Repeat with motor
> running, then top up the fluid.  Repeat again and you should be good.

Cheers,
Brian