The radiator is a heat exchange unit. Coolant circulates through the engine and is pushed through the radiator. The radiator cools the coolant and re-circulates it back to the engine. When a vehicle is moving, air flows through the radiator and cools the engine. When the vehicle is stopped, but running, the engine's cooling fan pushes air through the radiator. If a leak in the radiator develops, or it no longer cools the engine coolant, then a radiator replacement is necessary. Also the coolant system should be flushed periodically according to the manufacturer's specifications. If dirt or debris are allowed to remain in the coolant, then it could cause damage to the radiator.
When replacing the radiator, a technician drains the coolant from the radiator. Then the radiator and attaching hoses are removed. If a cooling fan switch and electric cooling fan are present, then they are transferred to the new radiator. The new radiator is installed, the hoses are attached, and the radiator is filled with fresh coolant.
When it comes to maintaining the performance of the radiator, you would be best advised to follow the factory recommended vehicle maintenance schedule for how frequently to flush the cooling system. This factory recommendation must be adhered by to maintain the validity of your new car warranty and extended auto warranty, if applied. If a radiator replacement is needed due to lack maintenance to the vehicle, the warranty would not cover the car repair.