>...The attendant rapped on the forward side
>of the Auto Stop fitting several times, and the leak stopped. Is
>there a spring
>loaded valve that got stuck? Could this be part of the mechanism covered by
>the small rubber cover?

I believe it is part of the auto-shutoff mechanism for filling.  When
it gets to a certain pressure, it shuts off automatically.  Once when
I tried to fill up, it would not take any propane even though the
tank was empty.  It had run out while cooking so I knew it was empty.
The filler guy did the same thing, tapped it a few times.  Said the
rubber should be flat, not sticking out as it was, He tried to push
it back in, but it wouldn't budge.  Nothing happened so I drove off
and used my backup camp stove.  Next day I was looking at it to see
if I could remove the valve and it was where it was supposed to be.
I returned to the LP place and received about 2 gallons, no problem

My guess it is a spring controlled valve that shuts off at a certain
pressure and mine was stuck.  Driving around a bit jarred it loose.
Next time the tank is empty and I don't need it for a while, I'll try
to take it off and see what is what.

Jim in Atlanta w/ '85 Westy