The Chevrolet radiator core is the section of your cooling system where the heat is removed from the coolant. The radiator core located in the middle of the radiator between two end tanks. The tanks are soldered into place if the core is made of copper, and can be detached if the core is refurbished. The aluminum radiator cores have their tanks welded into place, so the entire unit would have to be replaced rather than rebuilt. The replacing of the radiator core on a Chevrolet requires a skilled technician that specializes in this type of repair work. The fumes given off with the soldering are toxic and if Chevrolet owners decide to do this type of repair by themselves, they have to do it in a well-ventilated area. The replacement of the radiator core might be necessary for two reasons. Either a leak is in the small channels that make up the core or the channels themselves have become clogged. A leak can be cause by a puncture or due to corrosion on the interior or exterior of the radiator core. The second reason is that the channels have become partially or totally clogged. This is caused by not replacing the coolant at regular intervals and also the use of an aftermarket stop leak. These stop leak solutions do stop leaks but they also clogged the channels of not only the Chevrolet radiator core but also the heater core. The only recommended type of stop leak that should be used in your Chevrolet is course black pepper. This will plug the leak in your coolant system long enough for you to make it to a repair shop. There your coolant system can be flushed and the repair made permanent.