There is no return tank or even a flange, just a hole in the neck where it should be. My boss said it's a mystery as none ever hits the ground but plain as day, it pushes out the hole and from there is evenly distributed all over the radiator and back section of the compartment. I believe it is quite confused as the water is being moved by the impellor which is supposed to be a fan and the water pump impellor is acting as a fan pushing air around inside.