I would take over the overflow valve, it is a diesel antirector valve that have incorporated all the injecting pumps, we must not put any antiretorno anywhere because the pump already carries it. What do you say to let go of the tubes and put them in a carafe also cost you to start the same because when the tubes you have already made the circuit take air and you are in them. Take out that valve, it's like a corner, it has the hollow interior and small holes around. You have to take it by the head and suck with your mouth through the hole below, and then cover the aguejer with your tongue to see if the void endures you, if you take off your tongue is that the dock does not make strength and does not endure the pressure, which discharges the diesel circuit, that those engines do not have much mystery. If it is certain that the heaters are fine, there can not be many more problems, if you carry the fold of folded diesel or the awarder of the dirty deposit. Greetings!!