I'm replacing the fuel filler grommet because mine was
leaking when the tank was full or when I parked on a
slant.  Too many removals/installs dealing with a bad
tank and then bad grommets on top of the expansion tanks.

Anyway, I have a new grommet to install.  Bentley says
to check for leaks  and "seal if necessary."  How would
I seal it?  A ring of RTV before I inserted the filler
tube?  I don't see any evidence of sealant on the old
grommet, so it must have sealed well for about 30 years
before starting to leak.  ('81 Vanagon)

Any advice/experience with this grommet and having to
seal it would be appreciated.  [Please don't point me
to the other grommets and lines--the leak is at this
grommet and all else has been replaced and is OK.]

Thanks,
Richard