fuel tank breather

Gentlemen,

A friend of mine asked me if I could post a quick question here in the forum. He's got a fuel tank breather that leaks all over the place whenever he does aerobatics.

It's a small inox tube that's J-shaped. Once screwed into the top of the fuel tank, it basically looks like an up-side-down J on the wing.

Does anyone know how he could solve this issue?

Grubac

Install a check valve on the vent line that has a bleed hole. The door/shuttle/whatever should have a small hole in it (.020) or so to allow for vapor expansion in the tank when the door is closed. Andair makes them, although they are widely available from surplus aircraft parts suppliers like B&B.