Sight guage on header tank filling with fuel -

Actually the old tank appeared to have been repaired numerous times; was dented and corroded and beat up pretty bad. Had old gray sealant gunked all around the seams and the base of the filler neck - looked like JB Weld. Sloshing compound was most likely restricting the lines but we blew them all out when we put the new tank in so they are all now clear. What I also found was that the top of the inlet and the overflow standpipes inside the tank had apparently been replaced at some point in the past and placed way too close to the top of the tank; both about 1/2 inch or less from the top. Meaning the tank was always on the verge of overfilling. So you are probably right; some of the old sloshing compound had probably starting breaking loose and restricting the overflow line enough to cause the tank to begin to overfill worse and worse, to the point where every time I flew it came out of the vent and splattered against the windshield. New tank works great. The fuel gauge rod used to stay almost at the top of the Rain Pruf Gauge; now it rides about a third of the way inside the glass tube.

So, I am going to go out on a limb here and guess: Sloshing compound had plugged the return line to the wing tanks, hence the tank was over flowing as the pump filled it. Is that correct?

Tim, please feel free to call me at 816-803-0139. The 5 gal header tank in my 415C began to leak fuel out from around the cap also last fall. I thought at first it was the gasket, or the cap just not sealing tight enough against the filler neck. Even checked out the Rain- Pruf gage as Larry has suggested. My problem was none of these. The leaking got worse and worse and the old tank finally developed a crack and had to be removed. We found the tank had sloshing compound inside that was coming loose. The tank was also actually over filling with fuel and coming out of the vent in front of the cap. I eventually had to replace the whole tank with one fabricated locally by an expert welder. I've learned several things can be causing this and need to be checked. Call me and I'll be more than happy to share with you what I learned in solving my header problem. Lynn Nelson, Larry Snyder, and Marv Dunlap were invaluable in me being able to solve my problem once and for all.

Ron Mays
Kansas City MO
N99729

I have a slightly different issue. During taxi, my float rises to the top of the sight glass and then fuel pours out over the cowl. What is the cause? ai am not sure why it suddenly seems to overflow the header tank. It quickly stabilizes back to the normal float level but it makes a mess on the windshield.

I have a slightly different issue. During taxi, my float rises to the top of the sight glass and then fuel pours out over the cowl. What is the cause? ai am not sure why it suddenly seems to overflow the header tank. It quickly stabilizes back to the normal float level but it makes a mess on the windshield.