As an opposing opinion and my personal experience, my 7mm oulet tank with
the pre-filter increasing the hose size to the 11mm inlet of the pump (all
original from VW) has worked quite well without cavitation for the past 13
years with several cross-country trips under its belt (or tires as the case
may be).  This is the original tank and was cleaned and re-sealed when I
bought the blown-engined Ole Putt in 1996.  Although VW went to a 11mm tank
outlet late in production, I question the wisdom in eliminating the
pre-filter setup done say around the mid 80s.  The pre-filter is changed
every 3K (Oil Change), they're cheap (VW PN 133 133 511).

My nickel's worth & YMMV
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
75 914 1.8 (No Name Yet)
Full Timing Since March 1999
oldvolkshome@gmail.com
http://www.oldvolkshome.com
***********************************
On Mon, Apr 19, 2010 at 10:16 AM, John Meeks <vanagon@gmail.com> wrote:

> Dave,
>
> Check the fuel pump inlet size. If it's 11mm, be sure to get the tank with
> an 11mm outlet. Tanks with 7mm outlets going to an 11mm pump have been
> reported to cause cavitation and premature pump failure. busdepot.com has
> both size outlets.
>
> With a screaming pump, I'll be doing a re-replacement.
>
> John Meeks
> '91 Multivan
> Northern Michigan
>
> Vanagon Rescue Squad
> www.vanagonauts.com
>
>
>
> On Sun, Apr 18, 2010 at 3:31 PM, Dave Mcneely <mcneely4@cox.net> wrote:
>
>  > At some point my fuel tank was dinged, and evidently has a reduced
> > capacity.  It does not leak (and I don't smell gasoline at fill up, at
> least
> > not any more than with any vehicle, new or otherwise).  The tank is empty
> at
> > what I call 3/4 on the gas gauge, so I always refill it just before it
> > reaches that level.  It takes about 12 gallons to fill it when it is
> right
> > at that mark.
> >
> > At any rate, I am considering replacing the tank and whatever else I
> would
> > need to replace in the process.  Should I go ahead and put in a new
> sending
> > unit while I am at it, to forestall redoing work in case the unit is
> faulty?
> >  What else do I need to order for the tank replacement?
> >
> > The only online source I found for a fuel tank was Bus Depot at $160.
> >  About right?  Can anyone direct me to any other sources?  I did not see
> a
> > fuel tank listed at VanCafe, GoWesty, or VanAgain.  Do I need to rust
> proof
> > the tank before installation?  Why aren't these tanks polyethylene to
> avoid
> > the rust problem?
> >
> > --
> > David McNeely
> >
>

--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
75 914 1.8 (No Name Yet)
Full Timing Since March 1999
oldvolkshome@gmail.com
http://www.oldvolkshome.com
***********************************