rebuild?

[AW <weststar@ziplink.net>]

In looking through the archives, I found a posting regarding rebuild
kits for the auxiliary vacuum pump (for braking).  How good are they?
I'd like to avoid paying $400 for a new one, but will bite the bullet if
installing a new pump is the optimal long-term solution.  The archived
posting is quoted below.
Thanks.

Sincerely,
Andy

>From: J4KQ4me@aol.com
>Date: Mon, 2 Feb 1998 00:13:54 EST
>To: tturse@ps-b.com
>Cc: quattro@coimbra.ans.net
>Subject: Re: 85 4ksQ questions (3 part)
>Sender: owner-quattro@coimbra.ans.net
>
>Tom-
>
>  That knocking sound is most likely the vacuum pump that sits on the
side of
>the cylinder head... This pump helps intesify the manifold vacuum for
the
>brake booster. I can get rebuild kits for these.  It makes an
intermittant
>knocking sound when it does go, and it doesn't seem to affect
anything.  This
>pump is only on 1985+ 4000Q, 85+Cpe gt, and VW Quantum GL5s, and
Syncros, as
>well as 80s and 90s 88+. Gee, thanks VW Audi. Audi's silly list for a
new pump
>is like $400+ of course.  This thing went on both my 854kQ and my
former 86
>Cpe. It seems that the oil seal wears out, and the pump gets oil
logged,
>causing this wierd knock that can sound almost like a bearing knock.
Let me
>know if this sounds interesting....
>
>Jon.