Date:         Wed, 19 Oct 2016 23:57:26 +0000
Reply-To:     Richard Koerner <rjkinpb@SBCGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Richard Koerner <rjkinpb@SBCGLOBAL.NET>
Subject:      Re: Fuel leaking from Sender Unit on Replacement Fuel
              Tank--CONCLUSION
In-Reply-To:  <CY1PR20MB0029EED0C61CD6420B606DB4A0D20@CY1PR20MB0029.namprd20.prod.outlook.com>
Content-Type: text/plain; charset=UTF-8

Just got back home from mechanic....here is the story:
Yes, the tank is defective, more actually the tabs.  Maybe its due to improper engineered or old worn out cutting dies not cutting cleanly leaving a razor sharp undercut edge and uneven tank surface and tabs for the o-ring of the sender to try to cling to and seal.
My mechanic spent quite a bit of time carefully sanding the sharp edges of the tabs and bending "just the right amount" to allow installation and sealing of the sender (two-man job, one to press down and one to twist into position).  He then applied 5 PSI to the tank, and it successfully held pressure.  Filled up at gas station with success too...he did that before turning the van back over to me.

BTW....he had to replace the new Sender....the tabs had cut into the plastic....not worth spending more time and $$ trying to work around a damaged plastic part.

The Samba gives some good advice:  http://www.thesamba.com/vw/forum/viewtopic.php?t=513681&postdays=0&postorder=asc&start=20

Also, both GoWesty and Van Cafe offer warnings regarding the tabs being funky.
I don't see how you could do this job without having some apparatus (rubber plugs & bicycle pump?) to do the pressure test; you sure don't want to be removing and installing the tank over and over again to find out the bad news.
The whole reason for me replacing the tank was engine bogging at high ambient temperatures and high altitudes; partially clogged 7mm outlet on 31 year old fuel tank was the suspect, now I've got a 12 mm outlet and a clean fuel tank, so hopefully no issues for another 31 years.
Thanks for everybody's help and suggestions.  Just be forewarned and wary about defective fuel tanks if you do this job.  The vendor was informed of the defect, but I made the decision to go ahead and try to work around it; a replacement tank would most likely have had the exact same defect and would have added another week or two to getting my van back on the road.
Rich
San Diego

      From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
 To: vanagon@GERRY.VANAGON.COM 
 Sent: Wednesday, October 19, 2016 2:39 PM
 Subject: Re: Fuel leaking from Sender Unit on Replacement Fuel Tank
   
Send the tank back as a defect. The hole is stamped wrong. The only way to get suppliers to own up and improve quality is to make them aware of the problems. I have yet to see a problem with the senders or the O-rings provided with them (or the tank). The tank cut out is slightly off center so the O-ring doesn't seal. You shouldn’t have to fight it and any type of sealant here is an experiment and future failure. 

Dennis
 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Richard Koerner
Sent: Wednesday, October 19, 2016 2:59 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Fuel leaking from Sender Unit on Replacement Fuel Tank

I recently replaced the Fuel Tank and the Sender Unit on my 85 Vanagon; I purchased these from Van Cafe and had my VW mechanic install.  Initially had a BIG leak when filling up the tank.  Mechanic dropped tank and spent time bending and adjusting the tabs that hold the Sender Unit to get a better fit with the o-ring, and used a straightedge to try for as flat a surface as possible.  The leaking stopped (he pressure-tested and smoke tested)...but has now re-appeared when filling the gas tank to full.
It appears that MANY aftermarket tanks and Senders have this problem.
I'm thinking of applying some epoxy putty (gasoline resistant) when installing the Sender to fill the potential gaps of the mating surfaces.  Maybe some of the epoxy between the mating surfaces, and then build up a fillet of epoxy around the perimeter of the Sender Unit?
Any advice on this issue?  Van is currently over at mechanics....we are scratching our heads for a permanent solution.

Rich
San Diego