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A Lift-All which is working good has four positions. All the way out, to lift, should have a detent which is tripped when relief pressure is achieved because the cylinder has stopped. Half-way out, which locks the cylinder in the last position. Most of the way in, the ring on the handle about one inch from the handle guide. This position allows the cylinder to retract until it stops. When it stops, the flow is again blocked. I think this may have been used to drop cultivators to the ground level but keep them from digging in deeper as you cultivate. All the way in, with the ring touching the support (or nearly). This position is unrestricted return of oil to the reservoir. Not all Lift-Alls will hold on the detent fully out, of those that do, not all will release on relief. Not all will work at the "most of the way in" setting. I've not seen this described in manuals, but I have a couple that work like I've described above. When you drop a mower like a Haybine, on relatively flat ground, you can't tell whether the valve has locked up in the lowered position or not. But going over terraces, you can see that although the lever is "in", the mower stays in the flat ground position and will be held off the ground as you go over the terrace. You have to push it that last inch to let the mower fully float on the ground. I've tried to use this feature to hold a disc instead of using cylinder stops, but not very successfully. Of course all my Lift'Alls are old and worn. I have one in particular that is very hard to get past the lower stop. It is harder under pressure. I kick it with my foot, and the rod bows instead of the detent releasing. Sometimes it takes two or three tries. The stops are located on the valve body and you have to pull the Lift'All unit to get to them. I don't really understand what controls the lower stop or how it works. I think you can disassemble the valve mechanism and smooth the surfaces and help the action, but the front and rear ports are set up so on lowering the front port lowers first and the rear next. The lower stop is tied to the rocker arm opening the front and rear ball valves. All the way down, both port balls are held open. Part way down, at least one is held open by flow and when flow stops the valve closes. I suspect that if I used the rear port on the left side instead of the right port, I would not get the effect I have described, but it has never been convenient to try. It may help to plumb both front and rear ports together as your supply but I have not tried that either. Maybe someone else will offer more information.
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