SEAL 2761622 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
The machines listed above are exhibiting low hydraulic power, pump pressure that is not within specification, and the implement pump compensator will not adjust the pump pressure. Contamination in the hydraulic system can be trapped at the implement pump compensator. Contamination causes wear within the pump compensator housing and the compensator leaks internally into the implement pump. Once the internal leak becomes excessive, the implement pump may not achieve high pressure. Solution
If the machine is unable to reach the correct implement pressure and the implement pump compensator adjustment cannot be achieved, the implement pump compensator housing can be visually inspected for excessive wear at the load sense spool. If excessive wear to the housing is present, replace the pump compensator.
Illustration 1 g06295101A second method for testing for an excessively worn implement pump compensator is to temporarily remove the load sense orifice from the implement valve. Then, repeat adjusting the compensator. If removing the load sense orifice from the implement valve resulted in achieving the correct pressures, replace the implement pump compensator. Then, reinstall the orifice in the implement valve. The new replacement 347-0612 Pump Control Valve Gp is preset to values lower than the required specification for margin and high-pressure cutout. The new compensators must be set after installation. Refer to the Testing and Adjusting manuals in the reference section above for setting the implement pump compensator.For later built machines 924K (S/N: SNZ), (S/N: KW4), 926M (S/N: LTE), 930K S/N:FRK, (S/N: P3K), 930M (S/N: KTG), (S/N: HEY), 938K (S/N: REP), (S/N: W8K), 938M, (S/N: J3R) the 373-6990 Orifice Plug (Load Sense) is located behind plug (1) shown in Illustration 1. The inner orifice can be removed using a 4 mm allen wrench.
Illustration 2 g06330232For early built machines 924K (S/N: PWR), (S/N: HJF), (S/N: ENC), 930K (S/N: RHN), (S/N: EYE), (S/N: DYB), 938K (S/N: SWL), (S/N: XXT), (S/N: HFW) Orifice plug (2) Load Sense is located in the LS port on the inlet manifold shown in Illustration 2.Note: The Load sense hose will need to be removed on early K series machines.Contamination may also enter the hydraulic system on earlier machines which had tilt, lift, and steering cylinders featuring a snap-in wiper seal. The machines can be updated with the new press-in wiper seal and head design. Refer to the Service Magazines referenced above for more information.