leaking gas tank

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7414
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leaking gas tank

Post by 7414 »

Good evening,
Next week my 140 is due for its annual.
A few days ago I found my 140 in the hangar dripping fuel from the right wing trailing edge and a somewhat oily yellow substance covering large part of the right side fuselage, I'm burning non-ethanol car gas.
I'm counting on the tank having to come out of the fabric wing at the maintenance facility.
Can anyone who had a similar problem share their experience with me?
Thank you,
Marinus Hamer
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hotrodmac
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Re: leaking gas tank

Post by hotrodmac »

Oh man, I just went through this on the left side. It was a lot of troubleshooting and head-scratching until I bit the bullet and had the tank removed. Turns out there was a pinhole leak in the weld for the fuel line bung. Even under pressure, the tank never leaked, it just would weep. Every 24 hours I was wiping blue 100LL dye off the airplane. I thought I had it fixed after tightening the fuel gauge screws. I didn't have fuel on the side of the airplane after a flight, but I still had it the next morning.

Fortunately I have access to some great maintenance personnel, and the NC State Rep for The Association. Once we got into it, the repair was labor intensive, but fairly easy. We pulled the wing to make the fabric repair easier. The straps that hold the tank down are secured by phillips-head screws that go in from the bottom of the wing. The only "snag" we ran into was that the wings were painted with urethane a couple owners ago, so now I have a can of Poly-Tone on the shelf I cannot use...
  • First thing I did was tighten the screws on the fuel gauge. (Be careful the LAST thing you want to do is strip them!
  • Second thing I did was replace the quick drain -- multiple times
  • Third thing I did was replace the finger screen
  • Fourth thing I did was pull the tank.
Unfortunately, I don't have a picture of the tank.
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Last edited by hotrodmac on Wed May 31, 2023 8:45 pm, edited 1 time in total.
'46 C140 - Flying
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hotrodmac
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Re: leaking gas tank

Post by hotrodmac »

Finished Repair
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Re: leaking gas tank

Post by 8362 »

Had to pull the wing on mine. Had a small leak due to corrosion from the felt pad.
Good time to check the carry through spar. My IA had fun doing it, my checkbook not so much.
7414
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Re: leaking gas tank

Post by 7414 »

thank you for your replies.
do I understand it right that the wing has to come off if the tank has to come out and do the wing repair?
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