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Re: Hydraulic pump: rebuild or replace?


    The leak at the seam between the pump halves is a common failure on
these older "red tag" pumps. The rebuild job is fairly simple and no special
tools are required. An inexpensive (relatively speaking)  rebuild kit is
available which contains the required o-rings - you can get it from your
local dealer and it is probably available from other parts suppliers. You
will have to modify a drag link socket to remove the piston cover caps to
replace those o-rings. When re-assembling the pump halves, pay special
attention to the torque settings on the two cap screws holding them
together. You may want to loctite these screws; they sometimes tend to work
    If you want to change the shaft seal, you will need a gear puller to
remove the pulley hub.
    I recall a posting to the list which said there was one o-ring which did
not come in the kit - apparently it goes in the centre of the pump body
somewhere and requires some further dissassembly to get to. I did not come
across it when I rebuilt the "red tag" pump from my '86 5ktq, but then I
wasn't looking for it either.
    If you rebuild your pump, make sure you prime it to remove all air
before bolting up the hydraulic hoses - starting one of these with air in
them will almost certainly damage the pump!
    These pumps are a beautiful piece of engineering - it's worth rebuilding
one just to get a look at the internals!

Good luck!

Fred Munro
'91 200q  260k km ("green tag" pump - an even better piece of engineering -
it doesn't leak!)

-----Original Message-----
From: Wallace White <wallace@remdesign.com>
To: Quattro <quattro@coimbra.ans.net>
Date: Thursday, October 01, 1998 12:31 PM
Subject: Hydraulic pump: rebuild or replace?

>I'm gearing up for a full-on assault on the embarassing hydraulic system
>on my car. I've got the Jorgen rack on the way, and I started taking a
>closer look at the pump last night. It is leaking primarily (quite a
>bit!) at the seam between the two halves of the pump. Smaller leaks are
>coming from two of the giant draglink screws; one of those is right
>under the pressure line to the bomb, and I can't say for sure that
>there's not a leak where the line meets the pump.
>I took a look at the Bentley's pump rebuild pages last night, and it
>looks like there are a host of special tools involved. But I know that a
>number of people on the list have rebuilt these. Does anyone have a
>description of the process, sans VW 3642 or whatever?
>Am I better off just buying a "new" (rebuilt, probably) pump to replace
>it? I don't have a pressure gauge to check it, but I don't believe
>there's much wrong with the pump besides its seals. I've heard no
>moaning to indicate a bad bearing. But, if the rebuild takes a lot of
>time and won't necessarily fix it, I should go ahead and get a new pump.
>Thanks, as always, for any and all help.
>- Wallace
>  '87 5kcstq 150k