Improved replacement water pumps designed specifically for 2000 and newer MCM V6 and V8 engines For 50 years Sierra has been producing parts engineered to meet or exceed the specifications of marine engine manufacturers and has gained the confidence of engine manufacturers and boat builders to a point of supplying them with OEM parts. Boaters and technicians can be assured a Sierra part will fit right the first time and restore function to OEM specifications. The water pump is the heart of your engine s cooling system. Each Sierra pump is matched to the specific engine block used for your engine. Mating surfaces are machined for out of the box installation without additional preparation and the pump body is powder coated for maximum corrosion protection. Sierra water pumps are made from new castings and are not remanufactured. In recent years, Sierra has made improvements to this pump by using a vacuum impregnating process during the casting stages to prevent leaks. A circlip is included to eliminate movement of the pulley shaft if the pulley is not installed with proper tool. The proper pulley installation tool has been included to prevent damage to pulley shaft.