If you still have the old auto-stop valve, get rid of it. If there is a tube connecting the 20% valve and the fill valve you have it.

This is a common problem when the piston corrodes and sticks, which it eventually will.  Replace it with a standard RV tank valve and 20% valve. Here is one source:  http://www.anyrvparts.com/ProductDetail.asp?PID=11652&SID=29&DID=45&CID=229&BID=  I blew out a whole tank once when it stuck open after filling.  Can never to back to that fill station.

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dave Mcneely
Sent: Friday, March 14, 2014 2:48 PM
To: vanagon@GERRY.VANAGON.COM
Subject: propane filler valve

Had my propane tank (1991 Volkswagen Vanagon GL Campmobile) filled this morning.  An hour later I noticed a propane odor around the beast.  A quick check revealed a wet cap and frost on the propane filler valve.  Removal of the cap resulted in a slow stream of vapor, not with enough force to hiss, from the valve.  Looking into the valve revealed a stem or other cylindrical piece of brass visible, not normal.  I put the cap back on and took the van to the shop that filled the tank.  This time, removal of the cap released propane under pressure, and a hiss from the valve, with vapor.  Then it stopped.  Let the van sit for 30 minutes, checked again, no evident leak.  Used soap.  No evident leak.

Took the van to a shop that repairs and installs propane equipment.  The staff there detected no leak.  Shop foreman tapped on the valve with a ballpeen hammer.  Then checked again.  No leak.  Looking into the valve with the cap off revealed normal appearance, no metal visible in the orifice where it should not be.

I asked the shop foreman what he would do if he were about to drive several hundred miles and camp in the outback.  He said he would go.  I asked if he would replace the valve first.  He said no.  He suggested that if the same thing occurs again, I should tap on the valve as he did.

He filled the tank, and it required less than 0.1 gallon, actually not measurable on his gauge.

What say you guys?  BTW, he refused any payment, saying come back and buy propane, or repairs if and when needed.

 David McNeely