leaking header tank fuel cap

Larry where would I get the little rubber gasket under the sight tube? The one that goes between the tube and the metal cap?Does skyport sell them? Or can I just get a replacement locally as long as it's the same size?

Ron

Hi Larry, thanks for your quick reply. I have only owned the coupe since about 2005. It's always had the same header tank fuel gauge. Not sure if it's the Skyport Rain-Pruf gauge or not but it sounds like what you describe. My gauge is a clear test tube like device sealed at the top with a little plastic end cap. The thin metal rod inside the tube is attached to the cork float that floats in the gas in the tank. I have seen fuel bubbling up in the tube from time to time when it seeps. I've taken the assembly apart from time to time (every year or so) to clean the inside of the tube and have seen that little rubber gasket at the bottom of the sight tube you refer to. Hopefully replacing it will fix my problem.

I'm also wondering if it's possible there could be a partial blockage in the fuel line going out of the header? I took the cap off right after I flew a few days ago and looked inside the filler neck. The fuel level is right at the base of the neck. Also, I noticed a hard yellowish coating completely covering the inside of the neck, like a sealant type paint. I noticed the bottom edge was firm and solid but had come unstuck and was kinda loose at the edge of the neck. The coating seems intact but a small piece at the bottom of the neck about the size of your finger nail was missing. I'm wondering if there might be a tiny piece in the line somewhere that might be possibly restricting the flow out of the tank, thereby causing the tank to have too much volume and pressure? Is so could that possibly cause it to seep around the cap's main gasket? I'll keep my fingers crossed I don't have a blockage and that your idea will fix the problem. Thanks again.

Ron

Hi folks! I own N99729, a 1946 415-C with a C85. I have experienced a problem the last several years with a small amount of fuel seeping from around the rubber gasket of the header fuel cap. It only happens in flight and then only once or twice not long after takeoff. It isn't much, just enough to spray a thin coating at the bottom of the windshield about the size of a coffee cup. After several seconds it usually stops. Up until this last year it seemed to only happen occasionally when I flew. This past year it has started to happen more often, now on almost every flight. I can actually see the drops forming on the gasket when I'm in flight. I have replaced all the gaskets with new ones from Skyport. Even bent the metal locking tabs on the underside of the header cap upwards a little thinking that would make the cap seal more tightly and stop the seepage. But that hasn't stopped the leak. The fuel caps on the wing tanks don't leak. Does anybody out there have any idea on what could be causing this and how I can fix it? As information year before last the header tank developed a small leak and had to be repaired during the annual in October 2014. Thanks for your help, Ron Mays, Kansas City.