I have a leak from the top rear of my engine (1969), and I traced it back to the little breather hose with the fitting on one end going to the Injection pump, and the other to a banjo fitting that holds the oil pressure sending unit. Now, in front of that banjo bolt, is a mounted plate in a diamond-ish shape with what looks to be a little hose barb up in the middle of it. Does anything go on there? Mine's got nothing, obviously.

Thank you.