350 diesel tank breather tube

[Lavoy]

Not sure what that is, mine does not have it that I can remember. I just had to flush the tank on mine, pulled out a piece of stuff that I would bet good money was Silly Putty. If I had the comics nearby, I would have tried to lift a pic to prove it.
Your predicament is the number one reason I would never use old grease for fuel. I know many people do it successfully, but the one time it does not work, the cost of repair would buy you a lot of fuel out of the truck.
Lavoy

[dirtguy34]

It's the dip stick tube. don't know about any breather.

[Lavoy]

That could be, mine is real short, only up by the fill opening.
lavoy