BOOM & BEARING AS 3039127 - Caterpillar

How To Access Information
To select the correct Cat hydraulic cylinder seal kit in order to reseal a particular cylinder group, the cylinder group part number AND engineering design change level (C/L) of the group must be known. Group part number and C/L can be found on the outside of the cylinder group, either on a tag welded to the cylinder group, or etched onto the outside of the cylinder group tube. The etched number will be either laterally along the cylinder tube or around the outside of the cylinder tube by the rod (open) end of the tube.
Change Levels (C/L) Are Important For Ordering Correct Seal Kits
If Cat makes INTERNAL changes to our hydraulic cylinder groups, the group part numbers may not change. But, the engineering design change levels of the hydraulic cylinder group part number will change. The initial design of a cylinder group part number is considered C/L 00. Each consist change causes the C/L to be increased, that is 00 to 01, 01 to 02, etc.
Different Cat seal kits may be needed to reseal different engineering design change levels of the same Cat cylinder group part number.
For example, the heads of many Cat hydraulic cylinder groups were redesigned and a head wear ring was added to the cylinder group design. These changes in group design did not cause the cylinder group part number to change. Only the engineering change level of the hydraulic cylinder changed.
There was the need to create new seat kits for the changes to the cylinder groups in order to add the head wear ring for service. Caterpillar still services the earlier changes to the cylinder groups by maintaining the seal kits for the specific C/L that is indicated on the earlier cylinder groups.
Many dealers and customers continue to order the wrong Cat hydraulic cylinder seal kit to reseal their cylinder group. This is because they did not know the engineering design change level of their cylinder group when they started to order the seal kit that they needed.