I just bought a 1952 Cub on ebay and went down to pick it up this weekend.
When I got there I could see that there was a lot of leaking from underneath the hydraulic unit. Also it was "hiccupping" which is a term IH used to indicate while running with the mower raised the mower would sag a couple of inches and then like the tractor realized it it would snatch it back up over and over. When shutdown, the hydraulic system could not support the weight and would release it all the way.
The IH manual says this is not serious but does indicate it needs to be rebuilt. I got the numbers off the side(I'm listening to you guys!) and have located a rebuild kit for it and will rebuild soon.
My question to you guys who have rebuilt one - what do you use to wash this unit and parts with (what kind of solvent) and what kind of light grease do you use for the O rings?
PS - When I told my wife I was going to buy another Cub all she could do was shake her head as if she couldn't believe our good fortune!
See attached picture 1952 is the same model as me so I'm pretty excited to get this one fixed up.