Rapid Rogue Ballast Pump Impeller KitFor the well-being of your boat engine your water cooling pump must be able to supply a minimum specified continuous flow of cooling water. The flexible impeller in your pump, which provides this pumping action, is a wear part. Over time the impeller will lose its ability to maintain the pressure needed for the flow of cooling water and must be replaced. A good quality impeller will provide you with many months of problem-free operation. For an impeller of lesser quality the performance can degrade so rapidly that you, at best, must replace the impeller more often; at worst, you could be left adrift with engine damage.