Abstract: A heat exchanger is disclosed. A plurality of guides are integrally formed with the walls of a header tank and are used to position an oil cooler inside the tank to align a pair of fittings carried by the cooler with a pair of spaced openings in the tank.

Abstract: A secondary heat exchanger subassembly, such as a transmission oil cooler, is disposed in a metal tank of a radiator and has a pair of metal fluid fittings. Either a connector ring engages a fitting extending through the opening in the tank or a connector nut extends into the opening to threadedly engage the fitting whereby the metal fittings are held to the metal tank and inserted into a furnace for being brazed into sealed relationship with the metal tank.

Abstract: A metal tank cap is integral with a reinforcing member via a narrow connection and is flared outwardly at the narrow connection portion to be over an open end of the tank simultaneously with moving the metal tubes of the core into the tank. By unbending the connection portion, the respective tank caps are deflared into the open ends of the respective tanks and the entire assembly is placed in a furnace and brazed together.

Abstract: A one-piece header tank includes side edges that are overlapped and brazed together to form a joint positioned within the interior of the tank. The tank also includes an integrally formed mounting flange that may be fabricated without jeopardizing the leak integrity of the tank.