Torqued a flare nut to spec and it still wept, what am I missing?
Helped a buddy swap a fuel line on his 172 last Saturday and torqued the flare nut to the book number, but it still seeped a tiny bit. Pulled it back apart and the flare itself had a hairline crack I never would have caught without the dye. Anyone got a trick for spotting bad flares before you button everything up?
Man, I gotta disagree on the dye being the fix here. Dye only shows you the leak after the fact, it doesn't catch a crack before you torque down. What I do is hit the flare with a magnifier and a bright light before it goes anywhere near the fitting, and I run my fingernail around the cone to feel for any catch or ripple. A good flare looks smooth and even all the way around, no shiny spots or lines. Nine times out of ten a cracked flare started as a bad flare job, not a torque problem.