WATER PUMP

PURPOSE: To discharge cold water in a pump housing without splashing this to other parts such as a timing belt and the like by providing a draining mechanism loaded attachably/detachably being away from the back surface of an impeller for discharging the cold water in a direction back-facing the liquid sending direction of the impeller. CONSTITUTION: When a driving shaft 19 is driven by the rotation of an engine and an impeller 11 is rotated, cold water supplied from a cylinder head 3 through a pump sub-room 16a to a pump room 14 is approximately directly sent through a slope inner wall to a water supplying hole 14a. In this case, a drain plug 13 is fitted into an attaching hole provided in a pump housing 12 so as to seal a drain hole provided being communicated with the pump sub-room 16a in a side lower than the impeller 11, that is, in the lower part of the pump housing 12. In this position, cold water coming out of the drain plug 13 drops to the engine side and thus splashing of the cold water to a timing belt or a V belt is prevented.