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- May 18, 2016
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My A&P and I have stumbled on an interesting problem with my 1968 PA-28, serial 28-4823. My fuel cap gaskets are dried up and cracked, so I want to replace them. I removed the gasket from one of the caps (it damn near fell apart) and found that it doesn't quite match up to what I see in the 2009 Piper parts catalog. The parts catalog refers to part 66815-00, which is a 1/16" gasket with a 2" inside diameter (ID). The caps on my aircraft, however, have a 1/8" gasket and a 1 1/4" ID. I was able to find this gasket, interestingly enough, under the same part number from RealGasketsTennessee. I ordered the gasket and it matches up to the old one perfectly, but my AP and I cannot figure out how to get the damn thing on there. It's stiff Viton material and even when heated up with water it wouldn't get flexible enough to stretch over the tabs on the fuel cap. The fuel cap I have (see pictures) does not have screws to take the assembly apart and appears to be riveted together, so the only option I can see is to somehow stretch the new gasket over the tabs.
Both tanks have the same cap design, and I have good logbooks going all the way back on this aircraft and can find no record of the tanks ever being replaced. There are entries for vent and outlet hoses, as well as sending unit replacement, but nothing about the tanks themselves being swapped. I originally thought these had to be fuel caps from a different aircraft, since I couldn't find anything like this design in the current parts manual. On a hunch, I found a 1971 revision of the parts catalog. This revision lists the current 66817-00 fuel cap assembly just like the 2009 catalog, but also a 66572-00 assembly for my aircraft serial number - and the latter appears to be the one I have. So now I know that this fuel cap is likely the original cap and is indeed intended for my plane, and I have what appears to be the correct gasket, we just can't figure out how to install it. While the newer/current fuel cap design has screws that allow the cap to be disassembled, the model I have looks to be riveted together (see pictures). I also attached a pic of a buddy's 66817-00 (current style) caps with the screws just for reference. Also... I tried putting his cap on my plane just to see if it would work, but the handle doesn't align front-to-back like it should, so it looks like the older style cap like I have uses a differently mounted filler neck. Does anyone know how I can replace this gasket?
Both tanks have the same cap design, and I have good logbooks going all the way back on this aircraft and can find no record of the tanks ever being replaced. There are entries for vent and outlet hoses, as well as sending unit replacement, but nothing about the tanks themselves being swapped. I originally thought these had to be fuel caps from a different aircraft, since I couldn't find anything like this design in the current parts manual. On a hunch, I found a 1971 revision of the parts catalog. This revision lists the current 66817-00 fuel cap assembly just like the 2009 catalog, but also a 66572-00 assembly for my aircraft serial number - and the latter appears to be the one I have. So now I know that this fuel cap is likely the original cap and is indeed intended for my plane, and I have what appears to be the correct gasket, we just can't figure out how to install it. While the newer/current fuel cap design has screws that allow the cap to be disassembled, the model I have looks to be riveted together (see pictures). I also attached a pic of a buddy's 66817-00 (current style) caps with the screws just for reference. Also... I tried putting his cap on my plane just to see if it would work, but the handle doesn't align front-to-back like it should, so it looks like the older style cap like I have uses a differently mounted filler neck. Does anyone know how I can replace this gasket?
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