Abstract: A brazed in place heat exchanger core window is provided comprising a pair of coolant redirection boxes with coolant redirection tubes disposed therebetween. The coolant redirection boxes include a header and a pan, which are press fit to each other via overlapping legs. The headers include guides and slots to facilitate a press fit mating between the core tubes and each header, whereas the pans include ferrules to facilitate a press fit mating between the coolant redirection tubes and each pan. The core window is press fit to the heat exchanger core prior to brazing, and the entire core assembly, including the core window, may be brazed in a single operation.