Update--We have had two storms which required plowing. The hydraulics worked OK, but slow enough to indicate something just isn't right. Unrelated to this issue I plumbed a coupler into the work hose so I could completely separate the valve from the plow. Now there is pressure to the work port in both handle positions, and the cylinder will not collapse----however, if I shut off the engine and push the handle forward, the cylinder collapses just as I would expect. In reviewing the valve instructions, they said there is a plug in the outlet which must be removed if it is to act as an open spool. I removed the fitting in the outlet and could see there is no plug and the operating spool is clearly visible. I have reviewed the tractor manual re: hydraulic manifold and know the valve is plumbed correctly---tractor out to valve in, valve out to tractor in. I know I could remove the newly-installed coupler and return to original configuration, but I don't see how my problems are related to that. All I can think of is that there is some manufacturing defect or internal adjustment needed. Thoughts and recommendations requested.