I have a Kubota l2500dt with a loader lb400. The valve body has a plate on it with 1625-ar i can fine much on it. The problem is when I let the valve control handle go the valve is so loose it slide down in the the valve body it moves the bucket or arms on it's on. I don't know if I need to rebuild it or replace the hole thing. Can someone please give me some information about what I should do or something on that part number thanks, new to page and hydraulics.