Assorted intake and exhaust manifold gaskets for diverse applications. Used with permission of Detroit Gasket - Copyright© 1999.
When installing exhaust gaskets, also carefully follow the recommendations on the gasket package label and instruction forms. Read through all installation steps before beginning. Take note of any of the original equipment manufacturer's recommendations in service manuals that could affect engine sealing.
Each type of manifold gasket has its own sealing characteristics and problems. Therefore, be sure to follow the manufacturer's instructions when installing them. Refer to the manifold unit in the engine section of the service manual for specific instructions on the installation of manifold gaskets.
Manifolds warp more easily if an attempt is made to remove them while they are still hot. Remember, heat expands metal, making assembly bolts more difficult to remove and easier to break.
To replace an exhaust manifold gasket, follow the torque sequence in reverse to loosen each bolt. Repeat the process to remove the bolts. This minimizes the chance that components will warp.
Any debris left on the sealing surfaces increases the chance of leaks. A good gasket remover will quickly soften the old gasket debris and adhesive for quick removal. Carefully remove the softened pieces with a scraper and a wire brush. Be sure to use a nonmetallic scraper when attempting to remove gasket material from aluminum surfaces.
Inspect the manifold for irregularities that might cause leaks, such as gouges, scratches, or cracks. Replace it if it is cracked or badly warped. File down any imperfections to ensure proper sealing of the manifold.
Due to high heat conditions, it is important to retap and redie all threaded bolt holes, studs, and mounting bolts. This procedure ensures tight, balanced clamping forces on the gasket. Lubricate the threads with a good high-temperature antiseize lubricant. Use a small amount of contact adhesive to hold the gasket in place. Align the gasket properly before the adhesive dries. Allow the adhesive to dry completely before proceeding with manifold installation.
Install the bolts finger-tight. Tighten the bolts in three steps - one-half, three-quarters, and full torque - following the torque tables in the service manual or gasket manufacturer's instructions. Torquing is usually begun in the center of the manifold, working outward in an X pattern.