Mitsubishi D2350FD - Hydraulic

[Cowboyjg]

Howdy all. Hope everyone is well. Been a while for sure. Don't know about you but I feel like the last 16 months, all I've done is run around the edge of the plate trying to keep stuff from falling off.

So, to the question at hand. I have a gray market tractor. Been barn kept about 8 yrs and ran very little till about a year ago. I've used it more in the last year than all the others combined. Use it mostly for bush hogging as it has no loader. Anyway, I got around to doing fluid changes last week. I started with the oil and coolant. Ran it a couple days and parked it with the intention of doing hydraulic/tranny fluid change. Well, the 3pt hitch won't work. Keep in mind, for all the years I've owned it I've never (don't judge, long back story) changed the hydraulic fluid. So, since the 3pt hitch stopped working, I decided to go ahead and change the fluid and clean the filter, hoping that would fix the problem. Found a video on that process and filter location. Have no manual to reference. You'll see in the pictures that the screen on the filter has disintegrated completely. Now, I'm sure there are remnants wandering around inside the gearbox but what I don't know is to what extent, I haven't opened it up to see yet. And, I don't know how long this has actually been like this. Hell, it could have been this way when I got the thing. Came as part of a deal when I had to sell the Kioti. I'm searching for a replacement filter but the parts are rare. I found one that supposedly fits but they want $200 (WTF) for it. So, I'm checking other sources. Anyway, I wondered, what would be the ramifications of running it w/o the filter for a few hours. I really would like to see if the 3pt hitch problem goes away with the fluid change and filter. I don't relish having to replace the pump. Plus, I really need to move it to a more convenient location to work on.

Any input would be appreciated....

 

[Fedup]

I doubt the screen just disintegrated. More likely someone before you tore it off for whatever reason. Maybe it was ripped and not doing much anyway, something like that. Is there any other function the pump supplies other than the three point, and does that work? Yes, a tired pump could be the problem, but it may also be dry from lack of use, not picking up prime. If the pump is indeed not working because its dry, it won't help to run it a lot while troubleshooting. You risk making matters worse.

I admit I don't know your model, but I DO know tractors. Assuming the pump is engine mounted, has inlet and outlet fittings one on top one on the bottom, possibly fittings threaded into pump body but probably flange type with two or three bolts on each. Yes/no?

Once you re install the (sort of) screen and add the new fluid, I would start by removing the line from the top of the pump, whichever that happens to be. I would pour a teaspoon or two of fluid into the port, then bump the engine over to see what happens. If it's the pressure port the fluid should rise up. If it's suction, the fluid will just disappear into the pump. That will indicate the pump is turning at least, and so you move on. Object here is twofold. 1 you see if the gears are turning, 2 you put some oil on the gears which will help get things primed. If it's the suction port on top do this a few times to get a good coating of oil inside the pump. If it's pressure, then about all you can do is fill it up to the top, let it sit for a while and hope gravity helps out.

After that, I would check over any hose connections on the suction piping and tighten all hose clamps on them. I use a 1/4 drive ratchet and socket because it gets much tighter than I can do with a screwdriver. once past all that, if the pressure port happens to be the one removed, then start it back on but don't tighten it. If it was the suction pipe, put it back on tight and loosen the pressure line. Start the engine for a few seconds and hopefully the oil will start to flow. If it does, shut the engine off, tighten the lines and try again. If it still won't lift, you have more work to do.

 

[Cowboyjg]

This tractor does not have any other lifting devices. Only the 3 pt hitch. The machine has operated till just the other day so I don't think a dry pump is the issue. Although dirty, the fluid level was right on. The pump appears to be belly mounted to the gear box. There is a hard line from it to the gear box. I'm going to reinstall the filter cylinder with new oil and see what happens. I was reluctant to put it all back together the way it was until I knew a little more. We'll see what happens.

 

[Cowboyjg]

Update, well, sort of. Fedup, I thank you for your input!! The problem isn't resolved, yet anyway, but I'm hoping to get closer...lol. You are correct about the engine mounted pump. I'm attaching some photos in hopes you can impart some additional wisdom. Based on the photos, it appears that the suction port is on top. It's the larger tube that comes from the belly of the tractor. The smaller tube appears to be the pressure tube. It runs up the side and into the tractor where the lift piston is located. Part of my challenge here would seem to be that the suction tube is a hard pipe and in order to get to the top of the pump I might have to loosen the connection at the gearbox too so as get enough play. That would let the oil out. Weeeee. Anyway, I'm going to attempt that today. I'm curious if you can speak to what issues might occur at the lift control? It appears that the oil flows into the piston and then across to the control and through a small tube back into the gear box. I guess it's fair to say that the control serves the purpose of restricting flow to create pressure on the lift piston...? I dread the idea of having to remove the top of the gearbox... just saying...lol. BTW, that little pump goes for about $350 +/-. CRAZY .

 

[bordercollie]

Just curious if there could possibly be a knob like on the Kioti DK40 that I have that adjust the movement of the 3pt hitch ? My is located where your right heel would be just under the front of the seat. facing outward. It could have been kicked or moved ? Mine had somehow and really concerned me when my lift wouldn't work. I was blessed and relived to find that easy fix. collie

 

[Cowboyjg]

Maybe. That my friend is a good observation. There is this thing underneath that may or may not be that, for me. Going to have to check that out.

 

[Cowboyjg]

Here

 

[Cowboyjg]

Well my friend, as I happen to be out here when your reply came across my phone, manipulation of said device appears to have had no, I repeat no influence on the performance of the three-point hitch. I have to remember today's date. Could be that has some impact on all of this...?

 

[Fedup]

MOST three point lift systems have a similar devise built in somewhere. Its function is to adjust the flow of fluid EXITING the lift cylinder, in order to allow for heavy implements to be lowered as slowly as the operator chooses. They (usually) have no affect on raising or raising speed. On occasion it can get closed off entirely causing the lift to fail to lower once raised. That's about the only problem they present.

Back to the pump. What I would do in this case is loosen the bolts on the pressure flange below the pump, back them off maybe two or three threads. Don't remove them entirely. Just enough to make sure you have room for the flange to move away from the pump body. Move the lift lever to full down. Start the engine and let it run for a few seconds and see what happens. If the pump is moving oil, you'll know it instantly. If it's not, you'll know that too. Sometimes an engine mounted pump needs this now and again.

If you still have nothing, then loosen the bolts on the suction flange above the pump. Find an oil squirt can (they once were everywhere but now we have to hunt for one) filled with hydraulic fluid. Pry the flange up just far enough to allow for some oil to be squirted into the pump port and pump away for a bit and get as much as you can in there, tighten the bolts back up and try starting it again with the pressure line loose.

 

[Cowboyjg]

Consider it done. I will do this this weekend. If in fact this proves to solve the problem you I need to give me your marital status. If you're single then we may have to hook up. I'm only joking. But, you can see that this is pretty important. I appreciate more than you know the insight you are providing. I can build you a 15 story house but engine mechanics are not in my world. So, I am learning something new. And I'm good with that.

 

[Cowboyjg]

I was able to determine that the pump is working. Saw the gears move. Pulled the oil I put in. Also, if I remove the cap on the gear box, I can see the oil circulating from the port that enters the box. Sadly, It doesn't look like the pump is the issue. I really dread the idea of having to take the whole top off.

 

[Fedup]

Sorry but I don't know anything about the internals of that system to be of much help.

Typically with smaller tractors if the pump condition is the biggest part of the problem, I can usually tell with air pressure. I interrupt the pressure/supply line from the pump somewhere, set the lift control to full raise, and apply air pressure into the line. With lift arms bare, they will pop up if the system is working. If they don't, sometimes you can hear air bleeding off somewhere inside. I would probably fool around with that before digging in too deep.