Can AOS leak oil?

[sasha055]

I changed the part that goes from "oil cap" to "just behind AOS" and install all the rings back..

I'm still puzzled.. if any of the other two parts is broken shouldn't it be oily there? (lower near the the point of oil filler tube connecting to the engine)
In my case AOS (and the engine under it) has the most oil

Thanks
Sasha