In the last two weeks I motored for 20 hours. Fuel tank gauge is at 1/4 for aq 35 gallon tank. Went to fill up at the fuel dock and it would only take two gallons and began to overlow from the overflow vent and from the main fill. Checked tank and there are three hoses. The main fill, one to the vent, and one to the engine.
So the fuel should only exit the vent if the tank was filled. It is a Catalina 36 with a Universal 25 Diesel.
Any ideas what is happening?