Mitsubishi db2

[Icecheez]

Hi all! New here, somewhat new to heavy equipment. I'm working an Asian pear orchard and we have a Mitsubishi I think it's a DB2F, what it is it's a wide tracked swamp type with a six way blade. No one here at the orchard knows anything about it. Old owner bought it and died. It starts, runs, great. The blade works and it drive forward and back no problem. I was told that it would only steer in reverse. When I pull the left steering lever, nothing until I reach the end of stroke then full stop, both tracks. Right side nothing.
Upon closer inspection : the levers actuate a valve under the seat for most of the stroke then at the end of the stroke actuating a band brake. The left band brake seems to work, the right side is wet with I assume oil and sticks. Doesn't return when released. I opened the bandjo bolts feeding the valve, one gurgled out some white oil /water emulsion, then stopped. the other nothing. If I kill the ignition, then restart, it would gurgle out another teaspoon then stop again. The three oil resevoirs are apperently full. Not sure what to do at this point. This orchard is ten years neglected and in serious need of real equipment. Hands tools and power tools won't cut it. And the trees are blossoming already. I am very mechanically inclined but I need some schematics so I don't have to tear it all apart to figure this out. I'm not getting paid for this so I'm in a major budget. I'll profit from a good crop but that's months away. Any help would be awesome. If anyone in the area of Everett, WA could help in person, (social distancing of course) even better. Ten years of black Berry vines and other nuisance plants are taking over. There 's plenty of many variety of Asian pear for you who can provide help on site. Once they are ripe, of course. Thank you!

 

[Icecheez]

Here is a couple of pics of the beast.

 

[Old Magnet]

Better get to ebay and purchase some manuals,

 

[Icecheez]

I know, but my funds are currently limited. That's why I was hoping for help. Thanks for the reply.

 

[JimInOz]

The F series had no assist for steering.
It's a BD2G model Swamp or Super Swamp dozer .Has an S4E-2 engine.
Steering compartments should be dry (oil free) .
Steering trouble/repairs on these & all dry steer tractors is common.Lack of maintainence is also common,due to no manuals.
Look at the steeringclutch.com website & check out the BD2 parts/info there.
The last picture is an E series steer assembly ,but similar to later units.
Good little machines,if maintained.

 

[Icecheez]

Thank you, Jim. So I have looked at a maintenance manual, the drawings are quite rudimentary. But it gave me an idea of what's going on. It looked like the steering clutches are powered by a hydrolic pump in the main clutch housing. The dip stick in the clutch housing shows oil on it. Makes me think maybe the pump failed? Does anyone have a detailed drawing of that unit? My understanding is that it would be unlikely for that pump to fail because it should be a gear pump.

 

[Icecheez]

Could the wrong oil be the culprit?

 

[Icecheez]

So I looked at this thing again. Some one please correct me if I am wrong. It looks like the hydrolic pump is in the clutch housing, a couple lines go up to the radiator, and two to the steering valve, one is supply the other is return. Which would be why I saw a little gurgle out from one but not the other, then when you pull a lever it applies pressure to the clutch on that side. So assuming there is oil on the dip stick, then the pump must be bad. So I need to replace the pump. What if as a temporary work around I found a24v pump and hooked it up to the battery and the supply and return. I should have steering then right? Does any one know this system? It is a db2g super swamper. The blade uses a separate pump right? Why does the steering need its own oil cooler? Is it because it's a small system? I should also note that I was told it had a leak that would leave a trail sometimes, then forward steering would go out then reverse would one steer one direction before going out.

 

[Icecheez]

I found a service manual with better drawings. I am led to three possibilities, (in order of my perception of likelihood)
1.The steering bypass /pressure relief is stuck in bypass flow recirculating the oil directly back to the tank.
2. The oil solstice is incorrect and I actually need more oil,
3. The shaft of the pump (which I think sits external to the clutch housing) has sheared or broken or the pump gears catistrouphically failed and will no longer pump oil. So it is indeed a BD2G speed swamper.Does anyone that knows these machines have any thoughts? Please? Maybe a trick to pass on?
A couple more details ; oil coming out of the valve supply line is milky. But only a small amount. Oil on dip stick is clear. Oil is cheapest hydrolic oil available. (not my purchase) it has apparently been leaking to some degree for a long time, requiring regular top-offs, (possibly leading to contamination?) Thank you somebody for taking the time to reply with your thoughts! My next step in my mind is to clean the grunge off of the areas I'll have to reach into and disassemble the pump and pressure relief valve. I really need to get this size working before the black berry vines and other weeds. take over the entire orchard again. Wacking at it with a ten inch blade on a weed eater is slow grueling work and killing my back! The other tractors are down too. Two brush hogs and nothing to attach them to. I took apart a pump that may have been the original. It looks like it could have been in this machine before. May have come from something else. I don't think I get how it works as far as letting fluid go to the steering valve or bypassing back to the clutch housing. Looked like it hvs a metal cup in the end of a spring and a cone shaped thing in the other end blocking an oil passage coming from the gear pump.