“Besides the cooling leakage or a compression loss, oil retention could come into play. Most times with any MLS-type gasket, any leak is contributed to three things not being in play: proper torque settings, proper surface finish, and the gaskets not being fully compressed. An MLS gasket, when all three of these factors are correct, will not leak and hold a great deal of cylinder pressure. I would also say that adding an addition sealer, while it may seem like a good idea, really isn’t. The gasket already has a sealer on it, adding another layer of copper coat or similar keeps the gasket embossments from compressing fully to do what it was meant to do; think of it as hydraulicing the gasket in theory,” Hale explains.