The service and repair of a fan clutch start by draining the coolant partly and removing both the upper radiator hose and the air filter housing assembly. Unplug the fan/viscous fan drive assembly from the water pump using Tool 6958 and adapter pins 8346, but don't take out the assembly from the car right now. Mount the fan/fan drive assembly into the radiator shroud; after that, undo the two mounting screws and pull out the fan drive assembly and the radiator shroud. Don't set the viscous fan drive on its side after removing the fan blade/viscous fan drive assembly; this can cause the excess silicone fluid to soak into the lubricant. Following this, take out the four bolts seeing off the fan assembly from the viscous fan drive. Get rid of dust from the blades by gently washing them with mild soap and water. Do not bend or straighten the fan blades if they are not the right measurements. After installing a new fan blade assembly because of mechanical damage, examine the water pump and viscous fan drive as they might be damaged from excess vibration. Take the fan blade assembly off the viscous fan drive, place the fan edge-side-down on a flat surface and replace the fan if there is a gap of more than 2.0 mm between opposite blades. Also, change the fan if there are any cracks, bends, loose rivets or broken welds. For installing the fan, screw the fan blade assembly onto the viscous fan drive so that the bolts are secure at 23 Nm. Set the fan blade/viscous fan drive assembly into position in the radiator shroud, assemble and install the radiator shroud and fan drive assembly into the vehicle and tighten the fan shroud retaining screws to 6 Nm. Attach the fan blade/viscous fan drive assembly to the pump shaft, install the upper radiator hose, top off the cooling system and hook up the battery negative cable.