Last 2 time I filled up Vyk ('90 Syncro Westy), after driving for a while I
noticed a gassy smell by the right rear.  Well, the other day I noted that
some of the mud caked on the filler pipe that you can see in the wheel well
(looking up w/ head next to tire) was damp w/ gas.  Is this a problem with
th filler tube? the vent lines? or the (please please no) gas tank?  If I
don't fill the tank all the way to autostop, will this problem cease to be
an immediate issue ( I would assume so, as when the tank is not full, it
doesn't smell).

What's the next step in diagnosing/ attempting repair?

Thanks...
John
90 syncro gl camper
SLC