Viscous fan clutches engage and disengage based on engine temperature. When the engine is cool, the fan spins freely, reducing parasitic drag on the engine. As the engine heats up, the viscous fluid in the clutch thickens, causing the fan to engage and cool the radiator. a modern, efficient cooling system designed to reduce parasitic losses and improve fuel economy. The moving blades are a key feature adding to the system’s efficiency and responsiveness. Welcome to Congo Trading Parts. Located i