It leaks around the cap where they bolt to the valve block. When you take the spool out is there just the white nylon washer that seals around spool? Or should there be an o ring with it? This valve also has the regen or 'quick dump' on the bucket dump, and under high rpms it will stick, causing you to have to either drop rpm's or 'pop' it back in place. It springs to center just fine until rpm's are elevated. Its like it binds itself with hydraulic flow.