I've had to replace the one on mine and was not easy to find.  You could go
to the VW  dealer as they should have this available.  I ended up finding a
smaller diameter sized one, the place i got it from also sold me a thin
spacer about 1 mm thick that fit in the o-ring groove between the o-ring and
engine case.  The spacer gave the o-ring enough height to permit a proper
seal.
I was puzzled on why a simple o-ring was so difficult to find, but i was
told there are metric and standard size o-rings.  Obviously, this one is
metric size.
As info.
Claudio Cella
87  Vanagaon GL  7 pass
90  Jetta  TD

----- Original Message -----
From: "jesse johnson" <jjmojo@suscom.net>
To: <vanagon@gerry.vanagon.com>
Sent: Tuesday, October 21, 2003 5:14 AM
Subject: Crankcase breather tower...

> Hey all,
> My crankcase breather tower is leaking oil. I want to
> replace the rubber o-ring at the base of the tower. Does
> anyone know if you can buy the 0-ring at a hardware store?
> Or is it a special size that you need to get from the
> dealer or a vw shop?
> anyone?
> thanks,
> jesse
> 89 carat
>