2015 Nissan Pathfinder - Water Outlet O-Ring

The coolant outlet allows coolant to flow from the engine to the radiator, and is sealed with an O-ring to prevent coolant leaks. Coolant outlets may be made of metal or plastic, which can expand and contract as the coolant temperature rises and falls. The coolant outlet O-ring is made of rubber or nitrile, and is designed to also expand and contract to maintain the connection during engine operation and coolant cycling.