Your Chevrolet Trailblazer fan clutch minimizes engine drain and saves fuel by operating at different speeds under different conditions when it’s working properly. The fan clutch is supposed to run almost as fast as the engine when the engine is hot and run much slower when the engine is cool. Thermostatic springs should open and close the valve that regulates the fan’s operation. The valves also control the flow of viscous silicon fluid through the chambers in the clutch assembly. When the engine is cold, the fan will run slowly because the fan clutch is basically disengaged. As the engine heats up, the air flow to the fan gets hotter. The thermostatic spring unwinds and opens the valve once the air flow is hot. Once the valve has unwound and the valve is open, the silicone fluid will flow from the main chamber and engage the clutch. As this happens, the fan speeds up. A fluid leak or bad thermostatic spring or valve is the result of a bad fan clutch. You can determine if you have a fluid leak at the bearing seal in the center rear of the clutch by running your finger around the joint. If it’s leaky, you will get some black goo on your hand. The black goo is silicone fluid that’s leaked from the housing. If your thermostatic spring is broken, it will open the valve too soon. When the clutch engagement is premature, the fan spins much faster than it should. Any of these problems can be fixed by replacing your fan clutch. If you’ve decided that it’s time for a new fan clutch, shop with us. At carpartswholesale.com, we offer a variety of Chevrolet Trailblazer fan clutches at discounted, wholesale prices.