Yanmar 2g fuel return line

[Petersemple]

My Prout Sirocco has a Yanmar 2 G engine. When running the engine bilge collects some diesel and I think this may come from the fuel return line. This line has a “ T” section the top open to air and then heads off to the fuel tank although I cannot get to where it may enter the tank. The open end drips fuel when the engine I see running.
Any ideas how to stop this ?
Pete Semple

[classicone]

Should your diesel return line be open to the atmosphere? Mine was plumbed directly to the tank without a breather type opening.