Mark & duc1036, thanks a bunch for clearing that up!

My wording was clumsy and on top of that I didn't know the tank could hold both coolant and fuel so it wasn't easy understanding which part I was referring to. Unfortunately I don't know all the correct terms yet, but hopefully I'll get the hang of it sooner or later.

Does this part in some way replace the standard coolant tank mounted at the steering head or does it complement it in some way?