1985/04/01 Caterpillar

All 1100, 3100, 3200 Series Engines

Reference: The article "Improved Cylinder Head Gasket" in the May 21, 1984 edition of Service Magazine has the correct information for head bolt torque and the tightening sequence.

Cylinder block deck and head deck flatness must be maintained if the customer is to get the maximum service life out of the engine. If the cylinder block and head are not kept flat, it is possible for fluids (oil or coolant) and hot gases to pass through the voids in the joint. This can result in erosion of metal from the head gasket, head and block.

Whenever there is a head gasket failure, the flatness of the cylinder block and head should be checked before a new head gasket is installed. The chance of a repeat failure is much higher if the flatness of the block and head is not checked.

The flatness specifications for the cylinder block and head are:

A. Must be flat within 0.15 mm (.006") for the total length.

B. Must be flat within 0.08 mm (.003") for any 152.4 mm (6.00") length.

NOTE: It is especially important to check the flatness between the cylinder bores on both the block and head. The flatness in this area should be checked perpendicular to the crankshaft.

See the Specifications Section of the appropriate Service Manuals for the minimum thicknesses for the cylinder blocks and heads.