TUBE 3967054 - Caterpillar

Bolt Tightening SequenceThe tightening procedure for cylinder head bolts used on a high torque, shot-peened diesel head is as follows:
Typical High Torque, Shot-peened Diesel Head (A) Area of the cylinder head top deck that is shot-peened.1. Lubricate bolt threads and under head radius with engine oil before assembly. Do not use any other lubricant on the bolt threads.2. Tighten all bolts to 30 5 N m (22 4 lb ft).3. Tighten bolts 1 through 8 in number sequence to a torque of 400 35 N m (295 26 lb ft).4. Tighten bolts 1 through 8 in number sequence to a torque of 575 20 N m (425 15 lb ft).The tightening procedure for cylinder head bolts used on a nonshot-peened diesel head is as follows:
Typical Low Torque, Gas Or Diesel Head(B) Area with no shot-peening.1. Lubricate bolt threads and under head radius with engine oil before assembly. Do not use any other lubricant on the bolt threads.2. Tighten all bolts to 30 5 N m (22 4 lb ft).3. Tighten bolts 1 through 8 in number sequence to a torque of 270 35 N m (200 26 lb ft).4. Tighten bolts 1 through 8 in number sequence to a torque of 450 20 N m (330 15 lb ft).One way to damage a bolt at overhaul is to clean it improperly. If a bolt needs more than wiping off, clean it in a mild petroleum based solvent. Make sure the solvent has not been contaminated with water. If contaminated, the solvent will pit the bolt. Also, be sure and never clean a bolt with a chlorinated solvent. The chlorine will attack the bolt surface and leave pits. A pitted bolt will fail at low hours.
Loosening and retorquing a cylinder head bolt does not limit the number of times the cylinder head bolt can be reused. A bolt should not be reused if there is pitting in the fillet under the bolt head.See the Guidelines For Reusable Parts, SEBF8301, Inspection And Reuse Of Critical Fasteners For All Engines, for more information on reusing bolts.