It's been my experience that as the tank gets fuller, you do need to slow
down the fill rate or the pump will shut off.  Surging out can also happen.
The air in the tank is vented through the fill neck when filling and is now
usually sucked up by a vapor control system built into the pump nozzle. I
think the "camel hump" design of these tanks causes surging if you fill too
fast. The pump's auto shut off sends puffs of air down the fill pipe and
measures the time it takes the puffs to bounce back off the surface of the
fuel. When it rises or sloshes up the pipe it will shut off the pump, but
often not fast enough or too soon.

It's not your charcoal canister, if that was plugged your tank would
collapse as the fuel was drawn down. You probably had enough air leaks
before you resealed the tank to minimize surging.

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Gordon
Sent: Friday, January 13, 2017 7:41 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Gas tank hard to fill

I've been having a harder time filling my 89 Westy's gas tank more and more.
Something is blocking or causing back pressure such that the gas station
nozzle is made to stop. I am forced to slowly feed the tank an ounce at a
time and it takes forever with much spill over.  I've tried several stations
and it isn't them, I'm afraid.

I've heard of some filter? Or charcoal? In the way there?  Anyone know what
part may be the culprit?

Thanks,
- g=