So my fat lady got a Webasto and worked pretty well for a while, she's now mucking around... I could see air in the spilt line again and again, thought it was first because of a vacuum in the tank, that the small pump has not enough power to exceed this vacuum... now I did not completely close the tank cover at night, so that in the morning there should be no vacuum in the tank, this procedure unfortunately did not use anything....
Then I wanted to change the tank ventilation valve, while also withdrawing the return hose (where the heating is fed) and see there... far and wide no gas, but at that time immediately Spit to the pump (which was not connected yet, Sauerei
), I guess because of the expansion of the gasoline vapours, now it is really cold and so probably missing these fumes...Now to my actual question:
What exactly is the return line responsible for??? I installed the original sprite sensor (with check valve) and removed the valve in the tank (as in Rep-LF)