Sounds like something has changed about the valve. On some spool valves there is a bolt in the end of each spool that acts as a travel stop. My
speculation is the bolt in the end of that spool has worked itself out allowing the spool to be pulled out past the full open point and into another closed position. I will see if I can find a parts diagram to illustrate that.
Edit: OK - several different valves used on that loader and none of them have the bolt I spoke of but there has to be some sort of travel stop inside the end cap. Here is one of the parts diagrams as an example of what is "under the hood". Exercise care if removing the end cap - the detent mechanisms can sometimes jump apart and send small parts flying onto the floor.. I will timidly bet you will find your problem inside that cover. You might want to compare the distance that spool pulls out to the one next to it to see if there is any significant difference before taking things apart.
Dan
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Dan,
I finally got a chance to work on my tractor again after getting sent on long work trip. The valve is a HUSCO 9210B2A and seems consistent with the diagram you posted. I think you are correct about there being too much travel in the spool when I lift the buck up. Everything works correctly until the last 1/8th inch travel; then the buck stops lifting. I took the valve off the tractor and took the boom portion apart and took some pictures of the spool. I don't see any kind of adjustment for travel but maybe I am missing a spacer? Maybe it disintegrated an is allowing the spool to pull out to far. I did find something odd but I don't think relevant but I included a picture of it anyway. The little cup shaped piece (there are two of them) that holds the spring on the end of the spool had a small ring shaped portion break off. It still seemed to work as intended and the shaft of the spool cannot slide through it. I thought maybe the little ring piece that broke of was gumming up the works so I put everything back together and it still has the same issue. I found a kit for $90 on Amazon that seems to have the spring and keepers so I ordered it but I don't expect it to help.
John