Took rubber hoses off of the intake and the return diesel lines , to replace with new lines but didn't put them on for another day or two and NOW I don't know which one is the RETURN and which one is the FEED LINE.

Tried putting a squeeze bulb from a outboard boat tank and was able to draw diesel fuel from both lines. Thought that the return line would just be air, but I am drawing diesel fuel from both lines.

Is the upper line return fuel and the lower line feed????

Thanks for your help.

Dave