This hydraulic cylinder valve controls fluid flow to or from the actuator in the host machine's hydraulic system. It sits in the circuit between the control valve and the cylinder port, regulating the direction and rate of movement for the attached implement or header. A failing valve causes sluggish or uneven cylinder response, which can lead to inconsistent cutting height or header float. This is the original manufacturer's component, machined to match the bore and sealing geometry of the housing so that internal leakage remains within specification. On reinstallation, ensure the O-ring or sealing washer is replaced and that the valve is torqued to the housing specification.