So VW originally put a plastic cube filter here that also works as an
adapter since the early tanks had a 7mm outlet but the pump has a 12mm
inlet.  However in 84 some vans had a plastic cube filter before the pump
and a metal filter after the pump.  Probably because VW had decided to go
to an after pump filter but they still had some 7mm outlet tanks they were
using up.  After 85 they went with a 12mm outlet on the tank, no filter
before the pump, but a metal filter after the pump.  Here is why I think
they did this.  The filter before the pump can clog and restrict the pump.
If this happens a perfect good pump could cavitate and be wrecked  which
would allow debris to go down stream and into the injectors.  So you have
this situation where a bad filter causes the pump and injectors to be
destroyed.  Now let's think about what happens if you put the filter after
the pump.  If pump goes bad, it dies but doesn't destroy anything else.
Since there isn't a filter before the pump, unless the tank is full is
rust, the pump shouldn't need a filter.  So you are protecting more things
with the filter after the pump.  VW decided that was the smart way to go so
I think it was a good move.

Ken

On Sat, Apr 6, 2019 at 5:18 PM Tom Buese <tantonbz@gmail.com> wrote:

> The. Stock 84 had a small filter before the pump, but Vw changed that to a
> bigger filter after the pump for less cavitation in the pump, so I have
> read. I installed both new & old in my 84 years ago. Ymmv
>
> On Sat, Apr 6, 2019 at 5:11 PM Jack R <jack007@comcast.net> wrote:
>
> > Just about to wrap things up, get an alignment and have fun with my 84
> > this summer!
> >
> >
> >
> >
> >
> > Quick question, do you think I’m going to have any issues with the Fuel
> > Filter modification in the attached photo.
> >
> > https://photos.app.goo.gl/UM1j71P4RbYMcifa9
> >
> >
> >
> > I really wanted to have the filter before the pump, to help avoid crap
> > getting into the pump.
> >
> > It took a bit to get the system primed however, and after reviewing
> photos
> > from later  models, I realized that the later models have the filter
> > following the pump.
> >
> >
> >
> > Any thoughts on why VW decided to place the filter post pump?
> >
> >
> >
> > Thanks!
> >
> >
> > Jack
> >
> >
> >
> >
> > --
> Sent from Wherever I was @ the time
>

-- 
Thanks,
Ken Wilford
John 3:16
www.vanagain.com