Fuel Leak

There are dozens of posts on this site where people have had problems with leaking at the sending unit. Basically the new locking rings aren't as thick as the original rings. Therefore, when everything gets tightened down, the thinner ring doesn't press down enough on the sending unit and gasket. Everyone suggests using the original locking ring.

Somewhere on this site there is a good picture showing the thickness difference between old and new.

That said, the thickness of my 50-year-old locking ring is the same as the new, thin replacements. Aarg!