Fuel Tank Leaks

[fjdoug]

Mike,
I used a small cylindrical dremel stone.
the radius was a little more than the flange on the oops fitting; then I could grind with the shaft/shank of the dremel bit resting on the edge of the hole as a guide, and I ran around the perimeter of the hole grinding inside the tank.
i made a gauge out of .025 to check the thickness of the plastic.
Doug.

[Onex114]

I used a dremel cutoff wheel. Nice flat surface of the wheel produced a smooth and level inner surface with only slight downward pressure. Cut the entire surface in one motion.

[DCASonex]

The tool(s) consisted of a sheet of course sanding abrasive on open weave usually used for sanding of mud on drywall joints, tends to load up less than common sandpaper. Cut disk size of large washer, OD of which greater than size of boss to be smoothed out. Put long bolt through washer and abrasive and clamp abrasive to washer with another nut, which must be small enough to fit in drilled hole. Tiny bit of adhesive to help keep abrasive material from spinning on washer also helps. End of bolt sticks out through hole, turn with slow drill until surface of boss is smooth and thin enough that you can assemble the oops fitting and run nut on far enough to grip the flats on shank of the fittings. One of the reasons I cut groove for O-rings into underside of the nuts was to allow them to run on further without taking off a lot of material from the tank bosses as well as keeping O-rings from being mashed out from under the nuts.

Having spent some time under there, might be ready to find good local chiropractor. Have fun. When done, should not have to mess with it again.

David A.

[radfordc]

I repaired my tank using a simpler method. I removed the leaking fitting and drilled the hole out using a Uni-bit drill. I then tapped the hole using the proper size NPT pipe thread. I then screwed a brass plumbing fitting into the threaded hole. My tank hasn't leaked again in over 6 years.

[Fastcapy]

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[daleandee]

I repaired my tank using a simpler method. I removed the leaking fitting and drilled the hole out using a Uni-bit drill. I then tapped the hole using the proper size NPT pipe thread. I then screwed a brass plumbing fitting into the threaded hole. My tank hasn't leaked again in over 6 years.

Charlie,

I like your method and quite surprised that no one else had tried it. If I need to make a change your idea sounds best to me. Not sure why the fittings were not threaded in like this to begin with ...

Dale
N319WF

[DCASonex]

My O-rings also too large. Replaced with smaller ones on inside, but kept the larger ones on outside as they worked nicely with groove cut into under side of nuts. Also was not clear if O-rings supplied were Viton or not, another reason to replace with know material. Sonex purchases these fittings and does not make them.

David A.

[saddler]

I repaired my tank using a simpler method. I removed the leaking fitting and drilled the hole out using a Uni-bit drill. I then tapped the hole using the proper size NPT pipe thread. I then screwed a brass plumbing fitting into the threaded hole. My tank hasn't leaked again in over 6 years.

Charlie,

I like your method and quite surprised that no one else had tried it. If I need to make a change your idea sounds best to me. Not sure why the fittings were not threaded in like this to begin with ...

Dale
N319WF

I'm interested in this method. Could you expand on it? What plumbing fitting did you use?

[radfordc]

I used a pipe thread reducing bushing that I found at Ace Hardware. It was similar to these: http://www.discounthydraulichose.com/33 ... /33220.htm

Basically just a brass fitting that screwed into the plastic tank with the proper size internal thread to accept the original hardware used to connect to the tank.

I used a 3/4" NPT for the main tank outlet and smaller ones (1/4" NPT I think) for the others. I ended up replacing all but one of the molded in aluminum fittings in my tank.

The method for installing the fitting was to remove the original aluminum inserts by brute force, pulling them out with vise grips (maybe could drill them out too). Once those were out I drilled the plastic with a Uni-bit to get the proper size hole to thread with a NPT tap. I tapped the hole slightly undersize so that I was able to force the brass fitting into the plastic forming a fuel proof seal.

[Fastcapy]

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