Fuel leaking BETWEEN main tanks?

[ConwayB]

G'day All,

I have read a similar post regarding leaking fuel tanks, but so far have not found a similar problem to one I have recently discovered.

I have an O-2A(337B) with two main tanks and two aux tanks. The aircraft has not flown for about 8 weeks but I go and run the engines at least once a week for about 10 minutes. (We've been having terrible weather here in Queensland, Australia with hurricanes and massive floods and deluges). When I left the aircraft last week, it had 1/3 in each main tank and about 1/4 in each aux. (My left aux fuel sensor has not worked for a long while and has been a problem since importing the aircraft). This week, when I returned to the aircraft, I was shocked to find that my left main tank read almost empty, but my right main tank read 2/3 full! The aircraft was parked on a slight slope with the right tank lower than the left. I have not changed the position of the fuel cross feed valve.

Is it possible for fuel to leak from one main tank to the other through a closed (or faulty) crossfieed valved? I haven't had a chance to go through the manuals to check on the locations of any check valves.

And if that wasn't enough, now my left main fuel tank gauge/sensor is faulty. Augh!

Any advice would be appreciated. Bear in mind, the aircraft - at this stage - is sitting in the open due to lack of hangarage... and we've been having torrential rain here.

Cheers
Conway
www.ipas.com.au