A valve has a valve body with first and second intake passages, first and second supply passages and a reservoir return passage defined therein. A shuttle member is movable within the valve body between a first flow position and a second flow position. In the first flow position, the shuttle member defines a first fluid flow path between the first intake passage and the first supply passage and a second fluid flow path between the second supply passage and the reservoir return passage. In the second flow position, the shuttle member defines a third fluid flow path between the second intake passage and the second supply passage and a fourth fluid flow path between the first supply passage and the reservoir return passage. The valve is useful in a bi-directional hydraulic power system having at least one hydraulic component, a reservoir for hydraulic fluid, and a bi-directional pump.