DroogBC, failure of the upper radiator hose connection is a common occurrence with older radiators. The replacement Behr radiator should have a metal-reinforced upper hose connection. As mentioned I wouldn't immediately presume the head gasket has failed, although that is a possibility.

Be sure to use either MB coolant or Zerex G-05 (both have a neutral PH) mixed 50/50 with water. When refilling the radiator use a short length of clear hose (same size as radiator hose) turned upward so it acts as a funnel, and allow all the air to bubble out before connecting the upper radiator hose. With the clear hose it's easy to see when the radiator is full, but you could also use the upper radiator for the same purpose. Only then you're flying blind. You may want to install a new thermostat while you're at it.

After reassembly run the engine up to operating temperature. Then let it cool down and check the coolant level in the expansion tank. Add coolant, as required, to the full level. You should check the expansion tank level regularly for a while to make sure it's stabilized, and that no oil is in the coolant. Also, check the dipstick for signs of coolant in the oil. Either one would be the sign of a failed head gasket.

__________________
Fred Hoelzle