This O-ring seals a connection within the hydraulic system of a forage harvester or combine. It sits between two mating faces in the hydraulic circuit, preventing fluid leakage at the joint. A degraded or pinched O-ring will cause a visible oil weep or a pressure drop that reduces the performance of the hydraulic actuator it serves. This component is manufactured to the original cross-section and material specification, so it seats correctly in the groove and maintains the designed compression when the fitting is tightened. On reinstallation, ensure the sealing surfaces are clean and free of debris.