Cylinder Head – Bottom Deck
Remove the cylinder head from the engine to expose the bottom deck sealing surface. Before cleaning or machining of the cylinder head bottom deck, remove fuel injection nozzles/adapters from the head. Use a putty knife to scrape off any excess gasket material. With the valves still in place, thoroughly clean the bottom deck with a wire wheel or “Scotchbrite” pad. Use solvent or 8T9011 Component Cleaner to remove any oil, grease or loose carbon from the combustion surface and wipe clean.
If a metal reconditioning disk is used to remove gasket material, caution should be used to not remove any metal. If used too long in a small area, metal may be removed which may affect sealing surfaces.
Visually inspect the bottom deck of the cylinder head for damage. Determine if the combustion surface flatness is within specification. Occasionally, the head gasket fire ring sealing surface can suffer erosion or “Beat-In” following a gasket failure. If a depression can be felt in this area with the fingertip or fingernail, measure the depth with a 8T0455 Liner Projection Tool Group. Be sure the tool dial indicator is correctly calibrated before use.
If erosion or fire ring “Beat-In” exceeds 0.025 mm (0.001 in), the cylinder head combustion surface must be repaired by machining or the head replaced.
Erosion around the water hole is not critical if there is enough material left to support the water ferrule. Erosion in this area can sometimes be corrected with a room temperature vulcanizing (RTV) compound used to help seal the water ferrule.