Four coolant tubes

[Nickenaki]

Hello I am stuck with this problem and I would like to solve it without professional help.

I used to have a radiator at the back of my bus (ford e-450 7.3L diesel) and it had coolant tubes going to it. Now that I have removed the radiator I realize that there a 4 coolant tubes heading towards the back of the bus that are all loose and open. I don't know how this works. Are there two seperate circuits or is this one big circuit with the radiator?



Any help would be very much appreciated. Thanks a lot!