This is a sub-compact diesel 4wd with power steering that is basically a Mitsubishi rebadged by international. If I read correctly its a Mitsubishi MT2000. I bought it for cheap before last Christmas and everything worked, including 3 point, pto, etc. The 3 point lever is missing all its linkage but the previous guy just used vice grips on the hydraulic control rod going through the top rockshaft cover. I've been doing this too. It quit raising suddenly the other day using the back blade. Tried with no load on the arms, still nothing. Almost like I accidentally hit an off switch or something. There was no gradual loss of power or sketchy warning signs for months prior. I checked the hydraulic fluid level and quality, that seems fine. Though I intend to change it out regardless. There is an oil cap more towards the back of the tractor that is supposed to contain the mesh filter. I noticed that there isn't one in there. So I installed one of those. After letting it sit for a night in the garage with no heat, it worked again the next day like nothing happened. Yesterday I fired the tractor up to try it again and once again it didn't work. Very sporadic and unpredictable. No front loader on this tractor or other hydraulic implements just the three-point and the power steering. I'm wondering if the pump is weak. After letting it sit in the freezing cold overnight that's typically when the arms start to work again. I'm wondering if there is a screen that might be plugged up in that hydraulic system somewhere from not running a filter. There's also a valve that will prioritize power steering and the PTO clutch hydraulics over the raise 3-point arms if the pump pressure is too low. I was reading this yesterday in the shop manual. "Flow divider valve" i believe. The pressure relief on this unit allegedly uses "shims" instead on a simple threaded bolt or screw so I haven't attempted to mess with that. I'm certain that the 3 point raise function stops working with all levers and control settings in the same position as when it starts working again ( so I'm not accidentally bumping anything as far as I know) By the way it's worth mentioning that every time the three-point arms won't raise the power steering works perfect still. I don't have any way of testing hydraulic pressure. But when they weren't working yesterday I loosened up the high pressure line feeding into the Rock shaft area or the hitch cover. I had to loosen it quite a bit for hydraulic fluid to slowly start oozing out. Theres a knob under the seat for "draft control" or drop speed if I'm getting that right? It's reverse thread and when the arms weren't lifting I completely screwed that all the way out, no hydraulic fluid came out of the orifice. I apologize for my bad terminology. I've never worked on one of these systems (3-point) so it's very frustrating. The snow is piling up, so for the time being I'm installing a winch to raise and lower the implements. (Been meaning to get that winch on there anyway). If you have any input or experience with any similar problems like this I would greatly greatly appreciate it. Hopefully I post this right, I've never been here before. Thank you for your time.
I would try to pressure test the pump. A pressure gauge and hose would not be real expensive. The repair manual should tell you how and where to do that. I'm not real familiar with those tractors. You may have to leave the gauge on until it is acting up so you can just watch it. It could be the pump but it also could be a plugging pickup screen, or bad seal. Sometimes the power steering and brakes can still work well even though the 3-point does not because they usually take less pressure and also have priority.
I gotta dig through my stuff, or order a guage. I was thinking about unhooking the return going to the gear pump and looking for a pickup screen somewhere in there. I appreciate your response. It's hard to find input on tractors online.
If you read through the hydraulic part if the shop manual it should tell you where the pick-up screen is. It would also help you be more familiar with how the system works. I work on alot of tractors but have not worked on this model. By using a gauge to get some data you will be able to see what it is doing. Without being able to assign numbers to it you are just guessing, unless you have alot of experience with working in that particular machine.
The draft control could be the problem. If it's set wrong could prevent the 3pt. from lifting. I'm not familiar with that tractor but a lot of people don't understand what draft control does. Basically draft control adjusts the load on the tractor when using ground engaging implements like plows or cultivators. It raises the 3pt. slightly in harder soil so the tractor doesn't stop and just spin the tires. On a Massey Ferguson tractor if the draft control isn't all the way up the 3pt. won't lift. The max. lift height can be adjusted with the std. lift control and the 3pt. lifted with the draft control. If someone didn't realize the draft control lever wasn't all the way back/up the 3pt. won't lift with the std. lift lever. Maybe on your tractor the lift works when the oil is cold and thick but once warmed up and the hyd's. are working properly you need to adjust the draft or lift controls. Also if you have a live PTO the 3pt. might not lift with the clutch pedal fully depressed but will with the clutch half way down. The PTO and 3pt. could be on the same circuit for lack of a better word. It's pretty common.
I think WD might be into something. If you're missing the levers, the draft control might be moving with the position control. I'm guessing one control shaft runs inside a hollow shaft of the other and they're sticking and unsticking.
That's how Massey controls work.