Mitsu D3250 hyd problems

Bartender · Mar 26, 2006

Greetings!
A friend (Jerry) bought a D3250 FD Mitsu (an overseas model, apparently never sold stateside) from Cowlitz Tractor in Southwest Washington a couple of months ago. The tractor seems like a sweetheart altho it's had a troublesome series of small breakdowns - ignition switch, tach cable, etc. Now he's got no hydraulics. He's thinking about getting a new hydraulic pump but I'm guessing that there are simpler (and less expensive!) things that should be tried first.
Can anyone help us out with some direction? One of the participants on this forum told me there's no English manual so we're sort of groping about in the dark...
I'd like to try pulling out the relief valve & cleaning it, that sort of thing, but I dunno where to find it.

Thanks in advance!

lens12 · Mar 28, 2006

I have posted a reply to this question on another forum. Loosen the hydralic pressure line & crank the engine over to see if any oil is being pumpped

EFC · Mar 28, 2006

Can he take it back to Paula and have her fix it?

Are you getting oil to the pump if you remove the suction line? If so crack the pressure side with the engine running and it should go.

Buck

Lucky1 · Apr 6, 2006

Check filter on hydraulic fluid. Sometimes is all you have to do is clean filter.

Bartender · Apr 16, 2006

Hi, guys -
It's been a few weeks since I checked back here; didn't realize several people had taken time to post. Hi, Mr. Schaefer, Jerry bought the parts from you.
Here's where we are. Turns out it was the pump. It inhaled a tiny scrap of metal from the back of the tractor. Stopped in its tracks, shearing the pump input shaft off.
We looked at the strainer tube. The upper half of the brass screen was rotted off. The lower half was intact.
Jerry bought a new pump and screen from Shaefer Tractor. Put it all back together. With the 3-point control lever all the way up, we could not get it to pull oil. Took off the intake tube - yes, pump is spinning. No, it's not installed upside down. Replaced the O-rings on both ends of the suction tube yesterday. Still no joy. I tried compressing the transmission cavity with a little bit of air and got some oil to blurb out of the far end of the suction tube, but air leaks out from around the gearshift stick and the breather so I never got a decent seal. Disconnected the output tube and turned it 90 degrees so it was aiming into a bucket on the floor instead of going to the splitter block for the steering cylinder. Overfilled the transmission cavity by a gallon of oil, trying to get fluid to the pump. Still can't get any flow!
I'm no hydraulics expert, but it seems like we've eliminated all the variables. New screen, new pump, new O-rings, zero restriction on the outlet side - what are we missing? Any tricks you guys know of?

Maybe hauling it back to Cowlitz and camping out in front of their shop til they either refund Jerry's money or offer to help would be a good idea...

Bartender · Apr 22, 2006

Well, it's working. Sheez! We over-filled the tranny by about 2 gallons. Ran it for a few minutes, still no pumping.
There's a swagelok-type elbow fitting on top of the suction tube where it bolts to the pump. The tube coming from this SW-lok fitting turns downward and runs to another SW-lok fitting on the top of the hyd steering splitter block. I took this tube off and flipped it upside down so that the open end was facing up, with the intent of pouring some oil right down into the throat of the pump. We fired it up, and just for the heck of it I stuck my thumb over the end of the tube to see if I could feel suction. Flipped my thumb off the tube a coupla times, then oil started gushing out of the open port on the splitter block. We re-assembled the tube, started 'er up, and it worked. Jerry pulled the extra oil out of the tranny and it's still working. I don't know why it took so much effort to get the pump to prime but it's working now so thanks to everyone for the help and suggestions!

EFC · Apr 27, 2006

That’s great! Sucks you had to buy a new pump already though. The bright side is that it is good for another 30 years.

Buck

Bartender · Jun 3, 2006

Hey, everyone, thanks for the help.
Jerry's lost hydraulics twice now after running the tractor for an hour or so. Both times he's loosened fittings and found the pump is definitely pumping. After cleaning himself up, the tractor seems to recover. Maybe the oil getting hot and thinning out has something to do with this?
Cowlitz Tractor mentioned that there are (at least) 2 adjustments to the hyd system. One, somewhere on the splitter block, controls how much goes to the 3-point versus the power steering. The other is in front of the seat & I don't know what that does. Are there more? I don't know.
Can anyone give us some guidance on adjustments? I don't want to tweak on them until we have some idea of what does what. 1st thing I'd like to do is bias the splitter block toward the 3-point and see if that helps.
Thanks!

Bartender · Jun 3, 2006

Hey, everyone, thanks for the help.
Jerry's lost hydraulics twice now after running the tractor for an hour or so. Both times he's loosened fittings and found the pump is definitely pumping. After cleaning himself up, the tractor seems to recover. Maybe the oil getting hot and thinning out has something to do with this?
Cowlitz Tractor mentioned that there are (at least) 2 adjustments to the hyd system. One, somewhere on the splitter block, controls how much goes to the 3-point versus the power steering. The other is in front of the seat & I don't know what that does. Are there more? I don't know.
Can anyone give us some guidance on adjustments? I don't want to tweak on them until we have some idea of what does what. 1st thing I'd like to do is bias the splitter block toward the 3-point and see if that helps.
Thanks!