Friends 1997 Chevy Express 3500 Cargo Van is leaking coolant from the top oil cooler? line whick attaches to the top driver's side of the radiator.

What si the best way to repair this, permantly? Is a new radiator needed? Just the connection repaired, or new cooler lines?

Thanks!

A reputable radiator repair facility can repair the fitting if the tank and core are in good shape. If not, they'll recommend a replacement radiator. Sometime, depending on condition, it may end up a wash as to cost of repair vs replacement.