This solenoid valve insert controls hydraulic flow by opening or closing a pilot passage in response to an electrical signal from the machine’s control system. It is installed inside the valve block on the hydraulic circuit, where it directs pressure to shift a main spool that governs flow to an actuator. A failed insert can cause the spool to stick or fail to shift, resulting in a loss of function in the controlled circuit. The original manufacturer’s insert matches the bore geometry and seal arrangement of the housing, so the pilot pressure required to shift the spool remains within specification. On reinstallation, ensure the O-rings are replaced and the retaining nut is torqued to the specified value.