The cross-flow fin-and-tube design radiator in later model F-Series and Bronco vehicles has a vacuum-brazed aluminum core and nylon end tanks. The nylon tanks are molded with mounting brackets and attached to the aluminum core using tabs bent over the tank edge, creating a seal with an O-ring gasket. To replace or fix leaks between the tank and core, a home mechanic can follow these steps: open the tabs without excessive deformation, lift the tank, remove the O-ring gasket, inspect the core's seal surface, check and lubricate the new O-ring, position the tank on the core, clamp it with two clamps, tighten the header clamps to compress the O-ring gasket, squeeze the header tabs against the tank using locking-type pliers, conduct a leak test at 21 psi, and address minor leaks by further squeezing the tabs.