Before the use of modern rubber gaskets, many automotive gaskets were made of cork. Most commonly, cork gaskets were used for valve covers, timing chain covers, oil pans and intake manifolds. Like rubber gaskets, cork gaskets conform to any irregularities in the gasket’s mating surfaces. However, their cork construction makes them prone to tearing if improperly installed. Fortunately, cork valve cover gaskets are generally easier to install than cork gaskets for other components.
Remove the bolts holding the valve cover to the cylinder head with a socket wrench.
Tap on one side of the valve cover with a rubber hammer to break the seal between the valve cover and the cylinder head, then lift the cover off of the head.
Scrape the old gasket off of the inner lip of the valve cover and from the top of the cylinder head with a gasket scraper.
Apply a bead of gasket sealer to each side of the new gasket, then press the gasket into the groove on the valve cover. Note that some cork gaskets feature tabs that fit within slots on the valve cover to prevent the gasket from shifting. Make sure that the tabs and the slots align.
Place the valve cover onto the cylinder head, then tighten the cover’s securing bolt with a socket wrench only until the bolts are snug.
Tighten each valve cover bolt in small increments with a torque wrench until the proper torque setting is reached, as determined by the engine’s specifications manual. Tightening the bolts incrementally will ensure that the gasket seals evenly and does not tear.
