Donna-

Volvo doesn't supply parts for the radiators. There is a vinyl-type o-ring seal between the core and the tank. I haven't found anybody that can consistantly repair these radiators, so replacement is the only reliable solution. I have seen more than a few leaking at the tank crimps, some at both tanks. I always hook a pressure guage up to the cooling system and drive the car hard to make sure there is not a head gasket problem building excessive pressure in the cooling system and blowing the tanks off. Rare on the white motors- more common on the red motors.