Couple of things I learned doing this. After trying to get the oily valves on three times I improved the process as best as I could each time having never done anything quite like this before. With the tire and all the levers and the three point lift arms all in the way maneuverability in that area is tight for a big guy like myself. And twenty pounds of valves and hoses might not seem like much but at arms length they get heavy fast when you are trying to get three or four things to mesh at once. Each time I was loosing at least one of the innermost o-rings and backup washers. My first try went easy...I got it all tightened down and was trying to put the inner pin in the lever when I saw a backup washer on the axle...found two actually and had to take them all the way off again. Second try, same thing.
So this what I learned;
One, bolt the valves lightly together with the rear mounting bolt before putting the gang on the tractor. Leave all the other bolts in place too, as the manual states.
Two, as Mitch instructed, have the hoses already on the valves before putting the valves on the tractor.
Three, put the holding pins (if they are c-clip retained) in the spool and slide the levers to about a half inch from the end of the bar they ride on and hook the spool pins under the notches of the levers at the same time as putting the end plate on the bar. It was easier to hold the pins centered in place with grease before trying this. If your pins are cotter keyed this isn't as important, but putting those little pins and tiny c-clips on under the floor pan is frustrating to say the least.
and last but not least - in my case anyway, the most important: make certain the tiny little arrow on the lever end of the spool points down (towards the ports). Why? Because the manual says to.
I believe (but didn't prove it this time) that my problem with the base port not flowing oil to extend the ram was the result of me not paying attention to this one short sentence at the end of the assembly process of putting the valve back together. The two sensor holes in the spool have to be open to the return oil in order to pressurize and move the return poppet off it's seat to allow return oil to flow back to the hydraulic tank. After I got the offending valve back off and the re 0-ringed valve back on I saw that I had the arrow pointing up.
I made certain the arrow pointed down on the valve yesterday and it all works great now! I was having an issue with the original valve that I had taken off the first time, it wasn't self cancelling then or after getting it back on yesterday. (As I said before, I put all new o-rings in it). As it turns out I had turned the valve detent pressure adjustment all the way in which raises the pressure to self cancel beyond what pressure is available to overcome it. I turned the adjustment counterclockwise till it stopped (about a quarter turn) cycled the cylinder, it self canceled, turned it slightly clockwise and check, and keep doing this until it struggles just slightly to self cancel and then turn it back ever so slightly until the struggle goes away. This was my own idea since I don't have the test equipment to adjust it to the recommended pressures. I figure that with a 1,700lb bale on the bale forks that this should hold and not cancel too easily (This circuit is used mostly for my hydraulic top link).