PS pumps - the OTHER o-ring

[Orin Eman <orin@wolfenet.com>]

Some repair kits have a fairly large o-ring that doesn't seem
to have anywhere to go... no mention of it in the 5k or 200
Bentley.  A while back Scott Mockry told me it goes under
what the 200 Bentley calls the pressure relief valve retainer.
Well, my resealed pump was leaking again at the seam, and my
resealed spare leaked worse!  So, I attacked the original pump
today.

On taking it apart, the 6 o-rings and the large o-ring between
the two halves still looked fine.  So it was time to pull
the 'pressure relief valve retainer' out.  It's won't move,
so I started with the pressure relief valve (it has an
allen head and is recessed).  The retainer broke loose before
the valve came out, but then stuck.  I had to grab the
retainer in the vice and turn the rear pump housing by hand.
It came off - under protest.  Sure enough there is the remains
of an o-ring under there.  About 1/2" of the threads on the retainer
are destroyed - there is some kind of glue/sealer on the threads.
I clean the threads up a little and clean some of the sealer off the
o-ring seat before putting it back together.

I finished the reseal as normal and put it back in the car.
Center seam seems dry so far!

The 200 Bentley says that if there is more than 0.2mm between
the retainer and the pump body, discard the pump.
I guess the reason is that the retainer is supposed to be
glued in for the life of the pump.  If it works loose,
the pump is going to leak and a normal reseal won't help.
With the glue, it is unlikely that it can be extracted without
destroying the threads...  and it would need re-glueing.

Incidently, the 200 Bentley makes no mention of replacing the
pressure relief valve whereas the 5k Bentley does.  I wonder if
that's because attempting to break the valve loose tends to
break the retainer loose.

The latest reseal kits don't have this 'extra' o-ring.  It was
in the first kit I bought and I saved it just in case :)

Orin.