I have an AAZ in a T25 panel, bleed the system, took it for a drive, van got quite hot (over halfway) and spat water out the header tank overflow, I did stop the engine at one point and it was difficult to start like an Aircooled lump is when it gets too hot. I dont have an expansion tank behind the number plate should I? Its a 1982 1.6D, I have drained all the coolant, flushed the system, got a new tank cap and thermostat hpefully this will solve it. Picture of my engine bay below

Also, the pipe on the bottom of the pump by the thermostat should this go to the top or the bottom of the radiator? I presume its the top so cold water at the bottom of the rad returns to the engine?
thanks