Fuel Vent Discharge

[Steve Carpman11081]

The thru-hull for the fuel tank vent on our 1991 Legend 37.5 was originally installed below the level of the fuel deck fill. This would permit diesel fuel to squirt out during refueling. We eventually learned to catch this discharge with a wad of paper towels. As part of changing out our aluminum holding tank, we installed a new fuel vent line and moved the thru-hull so it is now higher than the fuel deck fill. Although this resolved the diesel fuel discharge issue, we now get a small quantity of brownish, sticky ooze leaking out of the fuel vent thru-hull. These leaks occur at times other than refueling. I do not believe this is fuel as diesel has a pinkish color. The new vent line we installed is approved for this application. Any ideas what is going on?

 

[Darrel]

Old Fuel In Vent Line

My hunch is that if you at one time had fuel coming out of that vent line, you probably still have fuel there. Trace the line, if it sags between the fill side and the vent stuff is probably trapped inside. Get something to blow the vent line out. Be prepared to catch it at the exit point. To avoid in the future, be cautious when fueling and don't over fill to the point that fuel comes out the vent. Allow room in the tank for heeling action as well. Another point. The vent line is just for that purpose, to vent the fuel tank. If you have an obstruction in the line it prevents air circulation and can eventually cause the fuel to not flow properly and cut off the engine.This was a learned expirence for me and corrected by a Company I had polish the fuel in my boat last year.Hope this helps and you can resolve to your satisfaction.