Leak undeneath upper radiator hose

Hi:
The radiator on your Focus is mostly plastic on the top and bottom, and the middle section is aluminum/ alloy. If you examine the radiator, and are sure it isn't leaking from the hose connection, then the radiator will need repaired. sometimes, small leaks in the middle , metal section are sealed just by using some radiator stop leak in your engine's coolant. A radiator shop can replace the top or bottom plastic piece on your radiator too, and often it is a good idea to check the price of an entire radiator at your local auto parts store, as sometimes you can buy a radiator for less than the cost to repair your old one.