Sonex fuel tank leak

[Nick]

Hi I have a new issue. I found a fuel leak on a 1/8" NPT fitting on the side above the fuel tank level probe. I tried removing and replacing plug with several different fuel sealants. So I think its coming from the brass insert itself. Thinking of trying to get a vaccume pump and see if I can get it to suck in some epoxy around the fitting. Has anyone else had this issue, and what was done to fix? All ideas appreciated. The tank is installed. Thank you all!

Nick

[daleandee]

Hi I have a new issue. I found a fuel leak on a 1/8" NPT fitting on the side above the fuel tank level probe. I tried removing and replacing plug with several different fuel sealants. So I think its coming from the brass insert itself. Thinking of trying to get a vaccume pump and see if I can get it to suck in some epoxy around the fitting. Has anyone else had this issue, and what was done to fix? All ideas appreciated. The tank is installed. Thank you all!

Nick

A known concern with Sonex fuel tanks. Good news is there is a fix ...

viewtopic.php?f=33&t=1916&hilit=oops+fittings

[gammaxy]

I had slow fuel leaks on the two fittings I left unused.

I left the plugs installed and created round patches out of HDPE sheet and glued them over the entire fitting. I machined a little pocket in them so they didn't interfere with the plug. The glue you use is extremely critical. More information on my old post: https://sonexbuilders.net/viewtopic.php?p=19049

Obviously, I was lucky it only happened on unused fittings and it prevents me from ever being able to use those fittings in the future without a bit of a hassle.

The patches have held up for 9 years now and I've been fortunate that the other fittings haven't also leaked.

[builderflyer]

Nick, I also had success using the Loctite "glue" that Chris recommends in his message. If you want to go this route and can't find the Loctite product locally, I'd be happy to mail you an unopened package of the stuff. I bought several packages of "glue" and only used one to do the job. Let me know.

Art,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,Jabiru 3300 #261

[Nick]

Thanks Art, Chris and all with answers. I am definitly going to try the glue. Will report results when completed. Thanks Nick

[DCASonex]

If you need them, the opps fitting tools are back in my shop. Only cost is to reimburse me for the costs of shipping them out by Priority Mail, (about $10.40.) when you return them. Suspect temperature change loosens the bond of the molded in fittings and the plastic tank, as plastic expands much more than aluminum. Contact me via private messaging on this forum with your mailing address.

David A.