All the german made water pumps I've ever gotten for vw diesels have a
plastic impeller.
Like I've gotten 60 of them over the years, black plastic.

I've never seen cavitation damage on any impeller, but I have on the
aluminum water pump housings of vw diesel and inline 4 gas engines.
Scott

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dennis Haynes
Sent: Tuesday, February 19, 2008 8:42 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Water Pump Impeller Damage

Who gets rebuilt water pumps for Vanagons or Jettas? Thoe worst I have
seen is the GMP brand. Stamped metal impeller that just does not move
enough water at idle. I have never seen a plastic or composit impellar for
a VW application.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Allan Streib
Sent: Tuesday, February 19, 2008 10:50 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Water Pump Impeller Damage

neil N <musomuso@GMAIL.COM> writes:

> Got some advice on brand names for replacement and was advised to
> get one with a metal impeller as the stock plastic one self
> destructs. I pulled it and sure enough, the plastic was
> deteriorating! Not sure why, but maybe something to do with a
> chemical reaction?

By the way, if you get a "rebuilt" water pump then be sure to check
the impeller before you install it.  I bought one for a Jetta years
back and the impeller had visible, fairly significant cavitation
pitting right out of the box.

Allan
--
1991 Vanagon GL