This cylinder head gasket seals the combustion chamber between the engine block and the cylinder head. It contains the high-pressure combustion gases and prevents coolant and oil from mixing between the adjacent passages. A failed gasket allows compression loss, coolant contamination, or external leakage at the head-to-block interface. The gasket is manufactured to the original material stack-up and crush specification, which ensures the correct clamping load is transferred from the head bolts to the block. On reinstallation, the head bolts must be cleaned and torqued to the specified angle-tightening procedure.