3.6 LITER. Water pump bolt. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Cooling System Crossover Line to a mounting point. Engine Coolant Inlet Flange Bolt. Engine Water Pump Bolt. Cooling System Crossover Line. Cross over pipe. Engine Coolant Inlet Flange. HEX Flange HEAD. Housing. Manifold.