my loader lift valve leaks on top of the valve @ what looks like a flat head screw driver big screw when in use or not in use the valve sprays out hydraulic fluid how do i repair? i have took apart the valve but cant get the big screw out , when i turn the screw it aligns the mounting bolt hole up and continues to spin when i turn it does nothing but that i didn't take apart the horizontal part from the lift arm. help