Cylinder head bolts thin out during use. Whenever the difference between the diameters «d1» And «d2» exceeds the limit value («d1» - «d2»: 0.15mm) bolts must be replaced with new ones.
Note. If the minimum bolt diameter is outside the point «62», indicated in the figure, measure it and take the value as «d2».
2. Deformation of the cylinder head surface:
Note. When carrying out this check, it is also necessary to check the deformation of the surface of the cylinder block.
Remove oil and water film from the surface with a scraper (like inclusions), gasket, sealant, soot, etc.
Note. Be careful not to allow water or gasket particles to enter the oil passages.
Using a straightedge and a set of flat feeler gauges, measure the flatness of the cylinder head surface in six directions. If the results obtained exceed the maximum permissible value, it is necessary to replace the cylinder head with a new one.
A. Straightedge.
B. Flat feeler set.