For gas engines, the radiator cooling fan can be serviced, repairs can be done by first disconnecting the negative
Battery Cable. Extract the coolant overflow/container from the fan shroud without removing hoses or draining the coolant. The
Water Pump hub shaft is connected to the thermal viscous fan drive/
Fan Blade assembly; the assembly is detachable by counterclockwise turning of the mounting nut, while the 36 Mm Fan Wrench prevents the pulley from rotating. At this point in time, don't attempt any removal of fan/viscous fan drive assembly and do not unbolt the fan blade assembly. Following that, take out the bolts that are used to attach the fan shroud to the radiator, and then pull off the lower shroud mounts from the radiator tank clips. This will allow you to take out the fan shroud and fan blade/viscous fan drive assembly as a complete unit. Store viscous fan drive vertically to stop the silicone fluid contaminating the lubricant. Take off the four bolts that hold the fan blade assembly in place on the viscous fan drive. Some engines have fans that rotate in reverse and are labelled with the word Reverse. If an installer puts on a forward rotating fan on a reverse rotating engine, it can lead to an overheated engine. Use mild soap and water to clean fan blades; don't use anything abrasive. In cases where mechanical damage led to the replacement of the fan blade assembly, check the water pump and viscous fan drive for damage caused by excessive vibrations. To install, attach the fan blade assembly to the viscous fan drive and tighten the bolts to 24 Nm (18 ft. lbs.) torque. Install the fan shroud after positioning the fan shroud and fan blade/viscous fan drive assembly as a unit. Position the fan blade/viscous fan drive assembly on the water pump shaft and tighten the mounting nut to a torque of 50 Nm (37 ft. lbs). After that, reinstall the coolant reserve/overflow or bottle and negative battery cable. When a new viscous fan drive is fitted, run the engine at about 2000 rpm for a period of approximately 2 minutes. This allows full fluid charge in the drive.