1992 240: gas fumes when tank is over 3/4 full. How to stop

[quillc]

I had the exact same problem in my 91 245. I figured that it was the sending unit gasket that failed. Turns out that there is another vent line on the top of the sending unit. It should be capped by a rubber cap (use one that is oil/gas resistant). I found the old one had cracked and fallen off. Pretty simple repair. Just take the metal cover off to expose the top of the sending unit and put a rubber cap (like the ones used for vacuum lines) on it and you're done.

Hope that helps,
CQ