This hydraulic O-ring seals a connection point within the hydraulic system of the host tractor. It sits between two mating faces in a coupling or manifold, preventing fluid leakage under operating pressure. A degraded O-ring causes external seepage or a slow pressure drop in the circuit, which reduces implement response and can introduce air into the fluid. This original AGCO part is molded to the same cross-section and durometer as the seal it replaces, so it seats fully in the groove without being pinched or rolled during installation. On reinstall, clean the groove and lubricate the O-ring with hydraulic fluid before assembly.