Hi,

Obviously my gas tank reseal and replacement of gas lines is working
great because now my gas tank builds up a vacuum while I'm driving.

When I stop, at some point afterwards I get a large thunk as it pops
back into shape.  If I take the gas cap off shortly after driving (eg:
to put gas in it), a large hiss and thunk as the vacuum is broken.

Going through the "Green Bible", about the only thing i can see that
should be "venting" the gas tank is the charcoal cannister?  Does this
sound right?

Do these charcoal cannisters get plugged?

I have no idea where to go from here :-(

I guess it's a good problem to have compared to gasoline flowing onto
the ground when filling the tank :-)

Thanks!
Steve Williams
(the other one ;-)

1991 2.1 Westfalia