How to Seal MLS Gaskets

Thursday, October 17, 2013

How to Seal MLS Gaskets

Head gasket designs continue to evolve. Natural material or composite gaskets sealed early engines but degraded quickly when exposed to combustion heat and chemical solvents. Solid metal gaskets provide additional heat protection but do not seal well under the expansion and contraction of rapid heating and cooling of metal parts. Multi-Layer Steel (MLS) gaskets contain multiple layers of steel sandwiched between flexible synthetic material to create a spring-like gasket that both resists corrosive fluids and addresses the need for a flexible gasket.

Instructions

Straighten and resurface the cylinder head to within the specifications of the MLS gasket, usually between 20 and 30 Ra. Straightening and milling should be done by a machinist with equipment capable of resurfacing the metal to within tolerance as other resurfacing methods, such as by hand, may result in irregularities to which the head gasket cannot conform.

Install the MLS gasket by placing the gasket on the engine block. For reusing MLS gaskets, it is possible to apply a very thin coating of RTV silicone to replace any small gaps in the .01 inch seal factory installed on all MLS gaskets. Both sides of the gasket should be recoated with the very thin layer or RTV silicone, if necessary.

Install the cylinder head on the engine block. Tighten and torque the retaining bolts according to manufacturer specifications.