Yamaha - Water Pump Housing Cover Cooling System Housing Component 6E5-44312-00-00. Overview. When you're inside a Yamaha lower unit doing water pump service, the housing cover is one of those parts you do not want to overlook. This Yamaha Water Pump Housing Cover helps seal and protect the upper side of the pump assembly so water flow stays where it belongs. If the cover gets warped, grooved, or damaged from heat and wear, cooling performance can suffer in a hurry. Using the correct OEM cover h