Mercury - Water Pump Impeller Cooling System Component Rubber Elastomer 89983T. Overview. There's something reassuring about knowing your outboard is pulling a strong, steady stream of cooling water every time you fire it up. Whether you're easing down a river channel, running across a lake before sunrise, or working a nearshore drift, that simple stream tells you the heart of your engine is doing exactly what it should. For Mercury and Mariner 30-70 horsepower outboards, the Quicksilver 89983T