This water manifold gasket seals the joint between the engine block and the water manifold, preventing coolant leakage at the connection point. It sits in the groove of the manifold flange, where it compresses under the mounting bolts to maintain a pressure-tight seal across the cooling system. A failed gasket allows coolant to escape externally, which leads to gradual loss of system pressure and overheating risk. The gasket is manufactured to match the original profile so it seats correctly without additional sealant. On reinstallation, clean both mating surfaces and tighten the manifold bolts to the specified torque.