I had occasion to remove the fuel hose from the gas tank outlet on my '87
Vanagon with a replacement, and found what the shop had done in replaceing
it was to use a smaller diameter hose that just fit over the tank outlet,
with the correct diameter to go to the fuel pump over that. I also had a
similar situation when using an aftermarket fuel pump on another Vanagon,
and the parts place suggested using clear tubing, what looked like aquarium
tubing, to make a sleeve between the two.

Ed in CT

>   The new tank's outlet looks to be narrower than the old one's: the same
> diameter as the line coming out of the fuel pump, i.e. the 7mm (?) line
> that runs to the engine compartment.  But that leaves me with hooking up
> the large-diameter fuel pump inlet to the small-diameter fuel tank
> outlet.  The shop I took it to (a bunch of VW old-timers who work almost
> entirely on air-cooleds) fashioned some kind of adapter out of what
> looks like copper tubing and solder to mate the wide fuel pump line to a
> narrower bit of hose connected to the fuel tank outlet.
>
>   I'd be laughing about it if it weren't leaking ever so slightly when the
> engine is off.
>