PUMP GP-UNIT INJECTOR HYD 3840678 - Caterpillar

3304 10E Industrial, 3304 13E Marine, 3304 83Z Generator Set, 3304 37Y Spark-Ignited EnginesDescription of Change: A new cylinder head gasket is used on the above engines. It has the following improvements over the former gaskets. ... A thicker fire ring and reduced overlap help to prevent leakage of combustion gases, and give a better "crush" on the liner flange when the head is tightened.... The overlap of the stainless steel fire ring wrap is reduced to give better gasket load distribution minimize the possibility of fluid leaks. The wrap has a tab-style design. This tab design results in a more flexible gasket that requires extra care in handling and storage.... Apply 6V4876 Molykote Paste Lubricant on the cylinder head bolt threads, bolt head and washer. This increases head bolt load by 15%.Adaptable To: The new 4P8915 Cylinder Head Gasket is a direct replacement for the former 7N8022 Cylinder Head Gasket. The new cylinder head gasket is in effect as follows: 3304...10E3641 Industrial Engine3304...13E1085 Marine Engine3304...83Z6536 Generator Set Engine3304...37Y1859 Spark-Ignited EngineAny time the new head gasket is to be installed, refer to the following topic so that maximum life can be obtained from the new gasket, head, and engine block.
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 (.0013 to .0069 in). ALSO, make sure that the differences between all four measurements at any one cylinder do not exceed 0.05 mm (.002 in). AND, the difference between the average projection of two liners next to each other must not exceed 0.05 mm (.002 in). These specifications are in the Service Manual for these engines.
Wear or erosion under the liner flange will require use of stainless steel inserts. See the following list of insert part numbers and corresponding thicknesses. The head and/or block surfaces may have been damaged if the engine was operated extensively after a head gasket failure.
9L5855 0.76 mm (.030 in)9L5856 0.89 mm (.035 in)9L5857 1.02 mm (.040 in)9L5858 1.14 mm (.045 in)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 383.10 mm (15.083 in), and is also in the Guideline for Reusable Parts SEBF8076. 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 98.89 mm (2.893 in), and limits the amount of material that can be taken off the bottom of the head.
The cylinder head bolt torque is 250 17 N m (185 13 lb ft). Follow the bolt tightening sequence in the Service Manual.