BMW 17227551636 Transmission Oil Cooler

ATF lines link the transmission to the ATF cooler which is a conventional type cooler situates at the back of the radiator. In cold engine start up, the engine water is heated up more as compared to the transmission fluid. The heat from the engine coolant is used to further heat the ATF higher so there is less internal drag in the transmission and helps gain an extra few miles per gallon. After the ATF rises to normal operating temperature it is hotter than engine coolant; thus, the ATF heat exchanger becomes a cooler.

To service the ATF cooler you will need to brave the belly of the car and here are the steps, First, take off the splash shield below the engine and then you will remove the cooling fan and the cowl. Depressurise the cooling system, when refilling make sure to shield the alternator from any detrimental impacts during the working on oil, coolant or fuel circuits. Remove the hose connection of the ATF cooler to the quick disconnect unions by turning the hose towards the oil cooler and at the same time trying to push the black ring present inside the hose at the end of the fitting until it pops out. Turn this lock counter clockwise and pull the ATF cooler away from the radiator as shown below. As for removal procedure, it is reversed in the process of installation; all sealing rings must be replaced, and only after putting on a lock and making it to click into place, the ATF cooler can be installed. Perform other services which include the checking of the automatic transmission fluid level, its refilling and bleeding of the cooling system and its examination for signs of leakage.