I built a fuel polisher sometime back and the pump failed. I replaced and because I used clear fuel line I was seeing air streaming through, not a lot but intermittent. I replaced most fuel lines with clear to see where it was entering as every other means to stop it failed. I tracked back to the fitting on the tank which is a square block threaded into a large nut which I resealed the adapter fitting and barb. The tank is almost full so the air must be entering above the fuel level. Anyone ever have a crack or such at the pick up tube? I am going to pull the tube to inspect, but haven't done so yet. I am hesitant because the tank is fiberglass and the fitting is substantial.
