Ok question, this is similar to the fuel assembly in my tank. The fuel line is connected but this( circled in blue) is open with nothing on it, is it a vent and supposed to be open?
On mine it is and went to a vacuum line that ended up going to the crab. after going through a bunch of ****.
I put a hose on that and ran it higher than the tank and put a filter on it to keep **** out.