Mercury - Water Pump Repair Kit Cooling System Series OEM Components 8M0113801. Overview. Anyone who spends real time on the water knows how much you depend on a steady, cool-running engine. When the water pump is healthy, everything feels smoother - the shifts, the throttle, even the sound of the motor settling in at idle. It brings a kind of quiet confidence that lets you enjoy the day instead of worrying about temperature spikes. The Mercury 8M0113801 Water Pump Repair Kit was built for that