MLS Gasket Installation

March 2, 2023

A multi layered steel gasket requires a flat surface with a proper finish. Improper sealing will result from having the incorrect surface finish.

A profilometer, a device which allows you to measure the roughness of a surface, can be used to verify the surface finish. However, a simple finger nail test will do.

Drag your fingernail over the surface of your cylinder head. Your fingernail should not catch into a groove. There should be no visible cutting marks or metal bead-over from a dull cutter. The smoother the surface, the better the initial cold seal of the gasket and the less likely you are to have problems with coolant and combustion leaks. Most gasket manufacturers do not specify a minimum smoothness spec for aluminum heads that have MLS head gaskets.

Ensure the surface is flat, clean, dry, and smooth. No additional sealant is needed. Applying a secondary sealant to a multi layered steel gasket will create more of a sealing problem compared to installing it by manufacturer specifications.