RECOIL GP- 5205154 - Caterpillar

Liner Projection and Machining the Block and/or Head
Do NOT adjust the liner projection above the block if it measures in the range of 0.03 to 0.15 mm (.001 to .006"). ALSO, make sure that the differences between all four measurements at any one cylinder do not exceed 0.05 mm (.002"). AND, the difference between the average projection of two liners next to each other must not exceed 0.05 mm (.002"). These specifications are in the Service Manuals for these engines.
Wear or erosion under the liner flange will require use of a stainless steel insert. Read the reference article about the new liner seat insert. The head and/or block surfaces may have been damaged if the engine was operated extensively after a head gasket failure.
To prevent entry of debris into the engine when cleaning excess Teflon from the block and head, use a clean Scotchbrite® pad only. Read the second reference article which gives additional guidelines on cleaning, inspection, and repair considerations. Be careful with a rotary pad to be sure the flatness of the block and/or head is not changed.
The maximum amount of material that can be machined from the top deck of the block is controlled by the minimum dimension from the crankshaft centerline to the top deck on the block. This minimum is 425.02 mm (16.733"), and is also in the Service Manuals. Use the 6V7840 Deck Checking Tool Group to measure this dimension. Special Instruction SEHS8187 explains the use of this device.
There is also a minimum allowable thickness for the head. This is 111.51 mm (4.390"), and limits the amount of material that can be taken off the bottom of the head.
Retightening Head Bolts
After installing the new 7E7308/7E7312 Gaskets, retightening the head after a road test or dynamometer test, or at the first scheduled check for valve lash is not necessary. The thicker fire ring and the reduced fire ring wrap increase the combustion seal and gasket body loading, which reduces the need for subsequent retightening.
Engines using the later 2W7984/2W7985 Gaskets should have the head bolts retightened. These two gaskets have no asbestos, and they use the standard thickness fire ring and wrap.
The cylinder head bolt torque, regardless of whether tightened only once or retightened, is 450 20 N m (330 15 lb ft). Follow the bolt tightening sequence in the Service Manuals, and tighten in three or four steps to ensure uniform loading.