Abstract: In an oil cooling system including an oil cooler housing (26) adapted to be face-sealed against a mating surface (46) including a port (47) connected to the high pressure side of a pressurized oil circulating system. The oil cooling system includes a base wall (60) on the housing (26) in a parallel relation to the mating surface (46), and an annular flange (52) extending from the base wall (60) and defining a radially-opening annular groove (54) that faces the port (47). An annular gasket (44) is located in the groove (54) between the flange (52) and the port (47) and has a flange-facing surface (68) that is complementary with the flange (52) on the side thereof defining the groove (54).

Abstract: A simple, reliable bypass valve construction (50) is provided for use in conjunction with a donut oil cooler (16) having a flat, solid filter plate (36), whereby the bypass valve (52) will be self-located and self-retained to the oil cooler (16) during shipping. The bypass valve construction (50) is easily accessible and readily replaceable so as to lend itself to serviceability. The invention is incorporated in an oil cooler (16) having a housing (28) with a surface (26) adapted to be sealed against an oil filter (14). The oil cooler (16) includes a plurality of interconnected heat exchange units (21) located inside the housing (28), with an oil inlet to one of the units (21) and an oil outlet from another of the units (21). There is a centrally located opening (39) in the surface (26) of the oil cooler (16) to allow a connector (18) to pass through the oil cooler (16).