My '85 diesel CUCV had totally lost all power, and would just cut off at stop signs. I talked to some people and thought a dirty fuel filter was probably the cause of it. So I took off the rectangular fuel filter and put on a new one, but now when I try to start it, the drain valve (at the bottom left of the assembly) just dumps gas out onto the ground. It's as tight as I can get it, what am I doing wrong? I've also got the air valve (on top of the fuel filter assy) tight. I've heard something about diesels air locking when you change the fuel filter...is this a symptom of air locking?