Hydraulic pump repairs

[Mike Arman <armanmik@n-jcenter.com>]

>From: Kneale Brownson <knotnook@traverse.com>
>Subject: Hydraulic pump repairs
>
>Anyone have a recommended place to send the hydraulic pump off my '86
>5kcstq parts car for rebuilding so I can replace my leaking pump on the '87
>5kcstq?   Should I just buy a rebuilt or a (shudder) new one?  The pump on
>the '87 has been showing mild  oil-wet discoloration on the front half for
>some time with no appreciable loss of oil in the reservoir.   But today I
>spotted (no pun intended) actual drips beneath the car and heavy signs of
>oozing oil on the pump, while the oil level dropped by a quarter of the
>distance between the high and low marks in just a 40-mile drive.


Kneale,

First, the bad news: I'm *NOT* in the business of fixing hydraulic pumps,
so sending it to me with $75 as Dave suggests won't necessarily make it
happen . . . besides, I'm going to Anguilla for a week on business, so it
would have to wait until I got back anyway . . . (Igor, do you want to do
this?)

Furthermore, I'd much rather sell you a set of Eurolights . . . (Come to
think of it, I just might agree to rebuild your pump for $75 if you also
agreed to buy some lights as a package deal ;-)

Now the good news: There really isn't anything to REBUILD; it is actually a
RE-SEAL.

The rebuild kit costs about $15 to $25 depending on where you get it. If
the pump works properly but just leaks, you don't have to disturb the
pressure release valve in the back half - this is sometimes loctited in and
cannot be removed without ruining it :-( and the only way to tell is try to
take it out - ugh.

Resealing consists of unscrewing the "X" caps (a real PITA - nothing fits
them properly) and re-torquing them after replacing the rubber o-ring
underneath each one. Use a little grease or rubber lube (Castrol, not K-Y)
because if you try to tighten the caps with the rings dry, they will
"smear" and be ruined.

The other half of the reseal is to replace the various o-rings between the
case halves. Once the pump is apart, check that the mating surfaces are
flat and unwarped - hold them against a sheet of glass. If they are warped,
glue a sheet of #400 wet-or-dry to a sheet of glass and lap the surface
flat. Remember to clean all the crud out before you put the pump back
together!!!

The shaft seal (which isn't that hard to change) almost never leaks, and
the two 4mm allens (which also have seals under them) also are pretty
trouble free. Be aware that removing the 4mm allens is a bitch, and at
least one mechanically competent lister reports twisting an allen key so
that it resembled a corkscrew. If they are not leaking, leave them alone.

You'll need a selection of aluminum crush washers to re-assemble
everything, and a liter or two of Pentosin.

Top hose: Notorious trouble spot. Take your old hose, which probably leaks
anyway, to a truck hydraulic supply place - I used the local Aeroquip
dealer. They'll make you a new hose (ten minutes - while you wait) using
your end fittings, and it will cost you about $25. It will also last
forever - these guys make hoses for bulldozers and army tanks, so this
little, bitty Audi hose is child's play for them. They will also throw away
the gooey, oil-soaked "protection sleeve" which makes such a mess under the
hood.

In addition to the very attractive price and super quality, the hose will
now have a section that can be loosened so you can twist the hose into the
CORRECT alignment, which makes it MUCH easier to re-install on the car
(more crush rings needed!). The tough end is the rack end - you have to
take the banjo fitting, add the outer crush ring, add the hose, add the
inner crush ring, and then get the banjo fitting started into the rack
without dislodging and dropping the inner crush ring . . . it sounds SO
easy (ha!).

(In fact, it is MUCH easier with the new hose because you can twist one end
of it without disturbing the rest. It's still not fun, but at least it is
now possible.)

This whole mess is less than a day's work the first time, and less than
half a day subsequent times.

Best Regards,

Mike Arman