Mike,

You probably have the infamous auto-fill valve.  I thought that by 89, VW
quit putting them on.  If you do, you can easily fix the problem yourself,
or take your van to a propane parts or RV store and let them do it.
Here is a reprint of how I fixed the problem, way before this list existed:

My 85 Vanagon had an automatic fill valve which caused nothing but trouble
at the fill stations.
Some even refused their service as it was not worth it to spend 15 minutes
and only put in 1/2 a gallon!

Here is how I fixed it:

Emptied tank by lighting burners. (outside with windows open)
Unscrewed fill valve and took it to a local propane parts store and bought a
plain manual fill valve for about $25.
Screwed new valve back in (used a bit of Teflon on the threads).  Make sure
the bleed valve
is still there and functional.

Went to a propane place and filled tank with no problem.

No problems since (about 11 years now).

This was a long time ago, I forgot all the details but use your common
sense.

Alfred
85 Vanagon

PS:  Donated the automatic valve to the brass recycling pile at the propane
parts store.

> I went to have my propane tank filled today on my '89 westy and ended up
> spending most of the afternoon at my local purveyor of propane and propane
> accessories all to no avail.  Apparently there's something wrong with the
> fill valve.  Anybody know a source for this part?(new or used)  The local
> propane and RV places are stumped.  Bus depot only sells the whole
> tank($220)  When they fill it the gas just leaks back out though a vent in
> the side of the valve.  These guys seem to know their stuff and they say
it
> shouldn't do this.
> -Michael