3-34. CYLINDER HEAD - MAINTENANCE INSTRUCTIONS (Cont).
(2) Abnormal operating conditions or neglect of certain maintenance items may cause cracks to develop in
the cylinder head. A careful inspection should be made to find the cause and avoid a recurrence of the failure.
(3) Unsuitable water in the cooling system may result in lime and scale formation and prevent proper
cooling. The cylinder head should be inspected around the exhaust valve water jackets. This can be done by
removing an injector tube. Remove such deposits from the cooling system of the engine by using a reliable
non-corrosive scale remover. A similar condition can exist in the cylinder block and other components of the
(4) Loose or improperly seated injector tubes may result in compression leaks into the cooling system and
in loss of engine coolant. The tubes must be tight to be properly seated.
(5) Both excessive fuel in the cylinders and overtightened injector clamp bolts can cause cracks in the
cylinder head. Always use a torque wrench to tighten the bolts to the specified torque.
Certain service operations on the engine require removal of the cylinder head:
Remove and install pistons. (Refer to paragraph 3-40).
Remove and install cylinder liners. (Refer to paragraph 3-40).
Remove and install exhaust valves. (Refer to paragraph 3-33.2).
Replace fuel injector tubes. (Refer to paragraph 3-34.1).
Install new cylinder head gaskets and seals.
Remove and install camshaft. (Refer to Direct Support Maintenance).