Hayden® 2790 - Severe Duty Thermal Engine Cooling Fan Clutch

A fan clutch is the part of the cooling system that powers up the fan blades. Each time your engine gets too hot, the clutch fully engages the fan. This allows the fan to blow the right amount of air onto your radiator for maximum cooling. Once the operating temperature of the engine goes down or the engine starts operating at a normal temperature, the clutch partially disengages the fan to save more power.

There are two types of fan clutches, non-thermal and thermal. Thermal fan clutches are a little more sophisticated and operate in response to underhood temperatures. A bi-metal thermal spring mounted at the front of the clutch senses the underhood temperature and operates the fan clutch accordingly. When the engine is cold, the fan is disengaged, providing fuel economy and noise reduction. When too much heat is generated, the clutch allows the fan to rotate really fast to cool the engine faster. The thermal fan clutch is engaged on a cold startup because the fluid drains into the working area when the engine is shut off. The fan clutch will slow down shortly after startup as a result of a pumping action produced by a difference in speed between the shaft and clutch body. Thermal fan clutches are available in standard duty, heavy duty, and severe duty options. If your fan spins excessively when the engine is stopped, the A/C performance is poor at idle or low vehicle speeds, or you feel vibration that increases with the engine speed, these are the signs of the failed fan clutch. Replace it with premium product from Hayden.