1945 M hydraulics

Hey guys, Just bought a 1945 M. My question concerns the hydraulic system. It has what Im assuming is the Lift-All system, 2 pressure connections on the left side of the tractor and one on the right. Im setting this up for a pull behind mower with hydraulic lift and I need to know if this system will do it and which fitting I need to use?

you can use any of the three ports. the rear port was usually used for a mounted cultivator, and a delay valve was put in the line so the rear cultivator had a delay drop. your hydraulics are not live, so the clutch needs to be out for them to lift. also they are one way hydraulics, so you can remove one of the lines from the mower so it uses power to lift and gravity to drop. they sell a vented cap to put in the unused port on the cylinder. if you need two way hydraulics, you can use an open center spool valve, run the pressure line to the in side of the valve and then tie the return line into either the fill pipe with a tee at the pmp or tee in to the drain plug. then tie the lift all control back so it supplys pressure all the time, when the clutch is out.

Lift-all in an M is just like the one in an H & I spent many hours on an H using the lift-all for cultivator, mower, etc. It needs a one-way cylinder, the lift-all pump has no "down" pressure, IH & every one else used gravity for down pressure back in the day. It should be able to lift your mower without a problem. We always used 30wt non detergent oil in ours, but we didn't have any other tractors that might have been hooked to the cylinder. You can use what ever you might have in any of the hydraulic systems that may be connected to the cylinder that you use, so you do not contaminate the other system(s). If you drain the lift-all and fill it with what ever you are using in the other systems, the lift all will not care, although it might not lift as quickly with thinner hydraulic oil. The two ports across from each other are fed from the same place in the pump, so use the one that is most convenient for you to connect to what you want to lift. I think (if my memory is correct) the ones on the side where there are two ports, the back one is a delayed lift, so the rear of the cultivator comes up a few seconds after the front gangs, so you "scratched out" your wheel tracks. I think oil did not flow (internally) to that port until the front ports didn't need any more oil to do what you wanted them to do. I would not use it, unless you want a delayed action, but if the front ports are plugged, it may react right away. We always used one of the ports across from each other when not cultivating. (My $0.02 worth. jal-SD)

If the front ports are plugged, the rear port will usually work but once in a while it will jam on you. BTDT. Use one of the front ports and make life easier on yourself.

Ok that sounds simple enough. Thats all it is, a power up gravity down mower. Im going to assume that pushing in the clutch and pulling the lift-all rod will release the pressure on the cylinder correct? I grew up on a super C with a belly mower so this M is a whole new ballgame.

Pulling on the rod will lift the cylinders and only if the clutch is out. If the clutch is in and you pull the lever nothing happens. Push the rod all the way forward and the cylinder will go down no matter if you have the clutch in or not.

That's how it is on my 45 M anyway!

T.C.