1.48 HYDRAULICS Oil cooler (73) (From Machine S/No.51200472 only) An oil cooler is fitted in the return line to the hydraulic tank (1), between the fan reverse valve (72) and the oil pressure filter (9). The oil cooler is attached by brackets to the machine structure with two bolts and washers. The oil cooler has three tubular cooling elements, through which the hydraulic fluid flows on the return to the hydraulic tank. The hydraulic fluid is cooled by engine coolant flowing over the three cooling elements.