Most large vehicles today are equipped with a sizeable fan mounted on the front of the engine in order to regulate temperature. Typically, these fans are controlled with a sophisticated clutch mechanism that is designed to manage operation based on certain parameters. However, this clutch can encounter problems and can fail, often without notice, so it is important to inspect and test the entire contraption at regular intervals. What do you need to know about the fan clutch, and how could it encounter a problem?
Fan Clutch Methods
There are various different types of fan clutch on the market, triggered in different ways but all with the same intent. For example, the clutch on your vehicle may be activated by the temperature of the air coming out of the radiator. If the temperature rises, it will heat up a coil that is built into the face of the clutch and this will, in turn, release silicone fluid to force the fan to engage with the driving pulley. Once the ideal temperature is met, a valve will close, and this will free the fan blades from the pulley.
Some vehicles use an electronic trigger controlled by the engine control module. Sensors will send a signal to the module and will activate the fan clutch as and when needed.
Another method matches the fan clutch to the speed of the engine itself. This is a less sophisticated system that is based on the premise that when the engine is under load, it will start to overheat and the clutch will then lock into place.
Sometimes, the bearings within the fan clutch can seize. Try to spin the fan by hand, and if it will not move at all, this is your problem. You can also try to move the fan mechanism backward or forward by hand. There should be no free play, and if there is, the bearing is worn.
Remember, a fan clutch will typically rely on silicone oil for its operation, and you need to make sure that this oil is always present in the correct quantity. Any sign of a leak should be addressed right away as complete failure will be imminent.
To avoid the risk of breakdown and costly engine damage, always ensure that the fan clutch is in proper working order. If you need to replace it, get the best manufacturer-recommended product on the market.
For more information on getting parts for your specific type of truck, contact a supplier of products like Mitsubishi truck parts.