Mitsubishi 1650 Hydraulic lift not working

[Jerry Amerson]

OK guys, here I am again.

I have been using my Mitsu for about three weeks out at our property getting it cleared. Mostly using the brush hog, and things have been working fine until yesterday.

I was hogging and stopped to do some edging up by the road and when I stopped I tried to lower the brush hog and it wouldn't drop. I remembered that there was a lever under the seat that affected the hydraulics so I turned it and the arms dropped like they should. What happened when they dropped is that the fill plug on top of the transfer case (I guess that's what it's called), popped out. It's just a rubber plug so I went to put it back in and noticed that I was very low on gear oil.

I started the Tractor back up and tried to raise the brush hog and I had no hydraulics at all. I tried moving the lever under the seat and still no raising. I then decided that I needed to get some gear oil so I went and got a gallon and poured it in. Tried the hydraulics again and still no action.

My first question is do the hydraulics that raise and lower the two arms extending to the rear work with the gear oil in the transfer case? If so, is there a place to bleed off any air that may have got into the system?
If the hydraulics use some other fluid like transmission fluid or power steering fluid where would that reservoir normally be?

Any help you give again would really be appreciated.

Thanks, Jerry

[mark777]

Jerry,

I'm thinking your internal hydraulic filter screen is clogged and filled with debris. This is typical in relation to most Japanese tractors, including many models that also have a spin on hydraulic filter.

I'm not absolutely sure on your model but I believe everything from the end of the bell hausing, back to the PTO is your entire hydraulic reservior and the filter may be behind your (large) suction return line. That line is on a flange bolted from the return pipe to the bottom side of the transmission/rear end (I think, and hope you have a manual).

Be prepaired for around 5 gallons of hydraulic fluid that should be drained before you remove the line to access the filter assembly.

Mark

[Jerry Amerson]

Thanks Mark,

I don't have a manual so I will just have to wing it but I think I can locate the return pipe and hopefully find the screen.

If anyone has a manual and can send me a pic or some ideas of what to expect that would be great. I now understand what that arm is for that is under the seat, it's the flow control valve for the hydraulics and that makes sense because I apparently had it locked and when I released it the 3PH dropped.

I will let you know how things go. By the way, I think this Tractor calls for 90W gear oil in the reservoir, is that correct because that's what I put in it.

Jerry

[mark777]

Oh No! 90wt is too heavy, I'm almost positive. Sure, it's fine for the FWD axle and gears....but way too thick for your hydraulic pump, especially when the outside temperatures drop below 80°.

Talk with this gent as he is a gray market Guru (and he may prove me wrong!): Len Sheaffer - Sheaffer town and country tractor www.sheaftractor.net - He might also have a manual he can supply you with.

Good luck and keep us informed.

Mark

[Jerry Amerson]

Mark,

I went out yesterday and believe it or not when I traced down the suction line to the reservoir directly across the case on the other side was a plate with a label on it "Drain and Filter".....:duh:

Anyway, I took out the bolts and sure enough there was about a 5" long cylinder filter that was dirty. I also drained out about 4 gallons of fluid. I cleaned the filter and replaced the fluid with the 80W because that's what Sheaffer said the manual called for. I got some mixed reviews about what to use because some of the guys on TractorbyNet said the manual was wrong and I should use Hydraulic Oil.

After putting everything back together I worked the lift a couple of times and then up she came. The 3PH is now working again, and I guess I need to just adjust the control arm under the seat so it doesn't come up so fast. It seems to work fine now so we will see how things go.

Thanks a lot for your help, and I'm sure I will be back soon with more issues.

Jerry,