Installation & Verification Guidelines Verify the part number and confirm main control valve assembly compatibility, including boom, arm, bucket, travel, and swing spools, relief valves, and holding valves. New or remanufactured valves must include hydraulic bench test reports for pressure, flow, and internal leakage of each section. For remanufactured valves, confirm spools are honed, repaired, or new. Replace all O-rings. Inspect the valve block for casting cracks and sand