What is this part, and why is it leaking?

[jbach36]

I noticed a big circle of diesel fuel under my car yesterday. This morning I went out and put a piece of cardboard under the car to see how bad it's leaking and it's just an occasional drop, maybe 1 drop every 15 minutes. But, a leak is a leak and they never get better.

So..... what is this part? I think in this area, I'm under the fuel tank but I'm not sure. It would only make sense since I'm pretty sure it's diesel fuel that's leaking. I did fill the tank up yesterday so maybe that has something to do with this leaking. Maybe it's an overflow or something?

1991 300d, 211k

[compress ignite]

The Specs for Vacuum release and pressure release are in the FSM.

There maybe should be some kind of Rubber "Bell Shaped" Open cover
on that "Thang" (It may in fact be there,BUT I just don't "See" it.

See: http://www.w124-zone.com/downloads/MB%20CD/W124/Index/602_603/47FuelSystem.htm

Section 47-0030

[Mxfrank]

That's the breather. Maybe you just overfilled the tank. You need to get the rubber covering, which helps prevent water intrusion.

[jbach36]

Or maybe I could just rig something up.