Mitsubishi 1650 3PH not working

Jerry A · Sep 2, 2008

Guys,

I recently purchased this Tractor and worked it over to get it in good condition. I changed all the fluids and greased it along with having the radiator rodded out and replacing the front tires.

It has been working fine until this last weekend when I was hogging. I stopped to do some edging and when I did I went to lower the brush hog and it would not go down. I thought about the control under the seat so I rotated it and when I did the arms dropped. When they did the fill plug popped out of the reservoir. I looked in and it appears that I have had a leak and it was almost dry. I went and got a gallon of 90W gear oil and poured it in. That didn't completely fill it but should have been enough for the hydraulics to work.

Anyway, I now have no hydraulics at all, no up or down and I have rotated the control valve both directions with no luck.

Can anyone tell me what might be wrong. Is it possible that there is air in the system now and I need to bleed it? If so, how do I bleed it?

I also had someone tell me that the filter screen might be clogged but I don't have a manual and don't know how to clean it so any help there would be appreciated as well.

Thanks,
Jerry

Kernopelli · Sep 2, 2008

Jerry A said:
Guys,

I recently purchased this Tractor and worked it over to get it in good condition. I changed all the fluids and greased it along with having the radiator rodded out and replacing the front tires.

It has been working fine until this last weekend when I was hogging. I stopped to do some edging and when I did I went to lower the brush hog and it would not go down. I thought about the control under the seat so I rotated it and when I did the arms dropped. When they did the fill plug popped out of the reservoir. I looked in and it appears that I have had a leak and it was almost dry. I went and got a gallon of 90W gear oil and poured it in. That didn't completely fill it but should have been enough for the hydraulics to work.

Anyway, I now have no hydraulics at all, no up or down and I have rotated the control valve both directions with no luck.

Can anyone tell me what might be wrong. Is it possible that there is air in the system now and I need to bleed it? If so, how do I bleed it?

I also had someone tell me that the filter screen might be clogged but I don't have a manual and don't know how to clean it so any help there would be appreciated as well.

Thanks,
Jerry

Just got done with a 3PH problem on my Mitsubishi today. Usually the first thing you want to check is the filter screen. I am not familiar with the 1650 but the filter will be inline with the suction (return) hydraulic line. Start at the hydraulic pump, it should be a gear driven unit on the side of the engine. It will have a small line, thats the pressure side and a larger diameter line, that is the hydraulic return line. Look for a cylindrical tube with a screw-off cap along this line or it may be inside of a square unit with bolts on top. Clean this screen and see if that helps. They are usually around the rear of the floorboard area, in front of the rear tire.
It is also possible that if the pump ran dry for long you could have damaged it and have low pressure as a consequence.
You could have a relief valve that is partially open or a malfunctioning control valve.
Some of the manuals say to use 90W but I think it is generally accepted that this is incorrect. Hydraulic fluid is what you should be using.
Do you have a manual, if not I would recommend picking up an I&T manual off ebay or one of the guys on the Mitsubishi forum. They usually cover a wide selection of models but generally they can give you good enough info to work on most Mits models even if a specific one isn't covered.

Jerry A · Sep 3, 2008

Thanks Man,

I will try and track down the pump and suction line and clean the filter. The reservoir was not completely dry because when I put the gallon of 90W in it filled up over half way. About the Hydraulic Fluid vs. 90W Gear Oil, would I drain the entire reservoir and refill it with Hydraulic Fluid? I think the reservoir holds over 4 Gallons, is that correct? Also, can I buy Hydraulic Fluid at an Auto Parts Store or where should I get it?

Jerry,

Kernopelli · Sep 3, 2008

I would go ahead and and drain the reservoir. My manual states 12.7 quarts for the 16-18 series Mitsubishis, 14.8qt. for the hydrostat models. For the fluid, I would go to any farm supply type store ( Rural King, TSC, etc.) and buy a 5 gal bucket. Most any brand they sell should be fine.
I also forgot to mention, check the linkage from the lever back, make sure nothing obvious is wrong. (missing nut, broken shaft, missing cotter pin, etc.)

Jerry A · Sep 4, 2008

Darryl,

I went out to the property yesterday because we are still moving stuff out there, and I have located the pump and the return line. It appears that the return line is attached to the top of the pump with 4 bolts so I am going to start there. I'm sure this will drain the Reservoir so I will replace the fluid after I get the filter clean and re-assemble the return pipe.

I looked under the cowl again and it says that the reservoir takes 80W Oil so I'm wondering about the hydraulic fluid. Doesn't this reservoir also serve as the lubercant for the gears? I'm definitely new at this and will go with the Hydraulic fluid if you say that's the way to go.

Thanks for your help, and I will start looking for a manual.

Jerry

Kernopelli · Sep 4, 2008

Jerry A said:
Darryl,

I went out to the property yesterday because we are still moving stuff out there, and I have located the pump and the return line. It appears that the return line is attached to the top of the pump with 4 bolts so I am going to start there. I'm sure this will drain the Reservoir so I will replace the fluid after I get the filter clean and re-assemble the return pipe.

I looked under the cowl again and it says that the reservoir takes 80W Oil so I'm wondering about the hydraulic fluid. Doesn't this reservoir also serve as the lubercant for the gears? I'm definitely new at this and will go with the Hydraulic fluid if you say that's the way to go.

Thanks for your help, and I will start looking for a manual.

Jerry

Yes, the return should be on top, no need to take it loose at the pump. Trace it towards the back, and the filter screen assembly will be plumbed in line w/ the return line and located close to the back of the floorboard area, but before where the line enters the transmission case. Mine for example is the cylindrical type and sticks up through the very rear of the left (sitting on the tractor) floorboard, directly in front of the bottom of the fender. The return line will likely be spliced with a rubber hose on each side of the filter assembly.

The gear oil discussion has been hashed out many times w/ the Mitsubishi owners and I have read many times that the gear oil in the transmission is a often repeated misprint and incorrect. This is the direction from the people who sell and work on these tractors and are generally considered experts on Mitsubishis. According to my manual, 80-90 wt gear oil is only for the front axle and hydraulic fluid for the trans. Yes, the reservoir is a shared system but this gear trans does not have to have heavy gear oil for proper lubrication. This is the same type system that almost every tractor I know of uses. Think of it this way, hydraulic fluid is very similar to automotive transmission fluid ( some tractor owners have even used it interchangeably), which is used not only to hydraulically shift the transmission but to lubricate the gears as well. 80 wt has a much greater viscosity than hydraulic fluid and while it will flow, is more difficult to pump and flow than the thinner hyd. fluid, especially is cold weather. I am not saying it will ruin your system, especially since you don't have a loader or other high flow need attachments, but I promise, hyd fluid is what the system was designed to use. I currently have 1300 hrs. using hydraulic fuid in the transmission reservoir if that adds any reassurance. I have also owned several other gear drive Mitsubishi models and all 3 were this way.

To drain the system, there are usually 2 drain plugs, one for the differential area and one for the transmission area (these are shared reservoirs), although I seem to remember some models may only have one drain plug ( mine are on the right side bottom of the cases). I don't think it is necessary that the system be drained unless the fluid is foamy/milky looking. Opening up the filter may cause some fluid to run out but it won't drain your reservoir.
Let us know what you find.

Kernopelli · Sep 5, 2008

Quote-""I don't think it is necessary that the system be drained unless the fluid is foamy/milky looking. Opening up the filter may cause some fluid to run out but it won't drain your reservoir"".

OOPS! Serious brain fart. Yes, I would drain the system of the 80 wt. After my dissertation on 80wt vs. hydro fluid I somehow forgot we were talking about the 80wt still being in the trans.

Jerry A · Sep 6, 2008

Darryl,

Well, I went out to the property yesterday evening and believe it or not as I traced the suction line back to the case directly on the opposite side was label "Drain and Filter"....

I took out the 4 bolts and drained the case and pulled out the filter. I is a cylinder about 5" long and was dirty so I cleaned it and then re-assembled and replaced the fluid. I went ahead with the 80W instead of Hydraulic Fluid because I have a leak and I think it would just be worse with Hydraulic Flluid.

Once I got it back together, fired her up and after a couple of actions with the lever up came the 3PH. I probably need to adjust the control arm under the seat to slow it down a little because it came up pretty fast.

Thanks for all your help and I'm sure I will be back with more issues.

Jerry