BVCRD wrote:
So what wears out, the nipple, or the threads in the head unit?
It's the angled tip and it's matching seating surface inside the filter head that wears out. It's a metal to metal seal, the two surfaces rubbing against each other, and with the relatively soft metals the bleed screw and filter head are made of, with repeated use the two surfaces can wear to the point they no longer seal.
That's why, as a more permanent fix, I've made an adapter that will screw into the port with an o-ring or gasket seal, so that I can then add a small valve that is designed for repeated use.