Flatness

When a cylinder head is removed because of gasket leaks, check the flatness of the cylinder head gasket surface so it conforms to specification using Straight Edge 303-D039 (D83L-4201-A) or equivalent and Feeler Gauge 303-D027 (D81L-4201-A) or equivalent. If necessary to refinish the cylinder head gasket surface, plane or mill up to 0.254 mm (0.010 inch) from original cylinder head gasket surface. Remove all burrs or scratches with an oil stone. If surface has still not cleaned up after the 0.254 mm (0.010 inch) pass, replace the cylinder head.