This is my very first post so please forgive me if I've overlooked something.

Recently purchased my first Disco II to tool around with. First project is diagnosing this leak. The line attaches behind the Pump Pulley and connects to what looks like a "smaller radiator" in front of the radiator. Engine searches to find the right name for this "smaller radiator" have come up only as reference to an Upper and Lower radiator but I can't actually find the appropriate part name. I just need some help finding the right name for the line and the part it attaches to so that I can search the repair appropriately.

It looks like a coolant.

Thank you in advance. I look forward to using these forums and getting this neglected vehicle back on the trails.