Fuel Venting from left reserve tank

[Cloud9sa]

Yeah, we just had to replace the cork gaskets on our G model. I 'spose it was due to the cold and dry winter air. Tracy

[CO_Skymaster]

Here is more information:

My aircraft went into annual in October 2009. It had empty aux tanks and about half main tanks. Along with a normal annual inspection I had my A&P working on many other items. One of which was my fuel gauges. The Aux gauges never worked and the main gauges were intermitted. As long as I was going to have the fuel gauges refurbished, I decide to have the entire instrument cluster checked and refurbished. The person working on my fuel gauges recommended that I have my fuel senders checked for functionality. After inspection, it turned out that all were either non functional or had some problems. I had all the fuel senders refurbished also. It was the end of January before the aircraft finally emerge with all the new repairs and upgrades. Performing the entire upgrades place me under financial strain and it has taken about 6 weeks to catch up. The aircraft was sitting out on the ramp during this time. Colorado has temperature highs of about 40s and lows in the teens around this time of year. Yesterday was the first opportunity I had to perform final post annual checks on the aircraft and fill up the main tanks. That's when all the fuel started pouring out from the wing airframe. I checked this morning and it finally stopped. I suspect a few gallons on each side poured out of the tanks.

After thinking about it today, I'm suspecting the gaskets on the fuel senders didn't seal and the fuel flowed inboard and leaked out into the airframe until the fuel level became low enough it could not leak out anymore. I called the A&P this morning and they already have it in the hanger. Hope he has some information for tomorrow.

Karl

[Cloud9sa]

The first pic shows how it was leaking in the wing and down the side of the fuselage. It was only leaking from the inboard tanks, both left and right wings. The second pic shows where the cork gaskets go. The rear gasket was leaking the most--the pic doesn't show how bad the leak really was, because it was wiped clean prior to taking the pic.

Click on the pics for a larger view.

[CO_Skymaster]

That's exactly what the side of my fuselage looked like. They found the problem, when they installed the fuel senders, they didn't tighten down the screws. Glad that was a simple fix. After all the effort to fix and upgrade during the annual, I hate to think here was another problem I had to fix. Thanks for the input everyone.

Karl

[hharney]

FYI
Be careful that the screws are not over tightened. They cause the light metal on the tanks to pull up. This can cause an irregular surface for the gasket and sender unit to seat.

This has been seen by Craig Griswold of Griswold Aviation on other Cessna aircraft. The Skymaster attach points could be different than what he had to repair on other aircraft but just something to be aware of.