Overheating / New Radiator

[Adam2201]

It seems to takes very little to go from the min line to pouring out on mine (especially if you've got a funnel in there, it's hard to judge). you can't see very well into my reservoir with it being old, so I tried adding a few ml just to be sure that what I thought was the coolant level was indeed the level.  It ended up with a bit too much in, which came out of the overflow pipe.

I didn't want to keep saying that the level was correct in the reservoir then find that I was looking at a line of old coolant dried on the inside!

Hopefully will get chance to have a good look at everything later, thanks again for all the suggestions,