Full size or mini? They have become one of my usuals with the rebuild decks (the ones for claptons, RCA I believe). Builds do good, then suddenly will leak. I've blamed the weather.
One problem is the top fill gasket gets stretched out and stops sealing, then it will really leak. And it's not like you can run to a hardware store for a replacement o-ring.
I don't know what you're using them on or what
coils to say. I use them with SS TC. Any flavor you want.