In Reply to: Still Need Help! 2N Hydraulics posted by Jack - Iowa on September 30, 2018 at 17:15:57:
Problems like won't lower and won't raise often have something to do with the relief valve. The relief valve can get stuck where it won't allow the lift to go down, and it can stick so fluid is always relieved back to the sump so the system can't make pressure. Both of those problems are usually caused by dirt/water in the fluid. The control valve can also get stuck, but since that one is moved by the touch control linkage, the worst thing that can happen is the linkage comes loose from the valve. I have temporarily "fixed" my lift by reaching in there "tractor off" and working both valves by poking with fingers. On the 9N/2N the relief valve is next to the control valve and both are below the PTO shaft, so you don't want to be sticking your hand in there with the tractor running. The control valve is shaped like a "T" with the touch control linkage spring-loaded on each end of the "T". It's not too hard to disconnect that linkage, but it can be a royal pain to reconnect. You have to get a hand on each side of the linkage, spread them apart, and guide each end onto the ball ends of the "T". It's easier with two people, but you still have to work thru the small inspection holes, mostly by feel. I made a special tool from a small block of wood that can be wedged between the linkage arms to hold them open. This makes reattaching the linkage easier. Get one end on the ball, align the other side, then flip the wood block out with a spare finger. I think, with the linkage off, the control valve can be pulled completely out. Not 100% sure about that, it's been a while since I had to fiddle in there. My hands are also size XXL, but I was still able to get one in there.
Here's a photo of my special tool, and the two valves. Looks like an open end wrench can be used to remove the relief valve. Remove them clean them and replace. Lift should start working again unless there are other linkage problems.
A permanent fix for sticking valves is to drain, flush, and put new fluid.