What is this cylinder and what does it do?

[paulfedex]

Hello,

I am brand new to your forum. I own a 1986 Prevost XL equipped with an 8V92TA.

I had an itch to go out for a short ride today. I started my bus and looked around for pre-trip issues. Oil is leaking from this little cylindrical tank mounted under the oil pan. Never noticed this leaking before. At low idle not so much, but at fast idle it will drip oil every 1-2 seconds! Trip canceled! A small line enters/exits out each end, going back and up somewhere (?), and the oil leaks from this ominous looking fitting in the center. So, I'm interested in two things if you have an idea: What is this tank and what does it do? Why is it now leaking?

I live full time in the bus and admit I do not travel in it much at all yet.

Paul