3-Point Hitch 3PH lifting arms not working

[eangler]

Hello,

I recently purchased a 94 L2900. I am a tractor noobie but am mechanically inclined. Hydraulics are a bit of a new thing for me but I get the basics.

So I went to try the 3pt hitch and the arms are "free floating." I can move them up and down with my hands. Position control does nothing. When I move the arms they are together and move with a small resistance and also make a couple light clunks.

Seems to me by looking into the oil fill port with a inspection camera that there are no fragments anywhere. So my first suspicion is that I have no pressure. My goal is to try to eliminate the external / easy stuff before tearing into it. I studied the parts and I think I figured out that the hydraulic supply comes to the lifting arm section via a hard steel line from under the right side of the machine. That block also supplies the FEL and backhoe. The line goes up under the seat into a block where the lowering speed control knob is.

How can I figure out if pressure is getting up there? Is it reasonable that the large-ish (16 or 17mm socket) plug on the right of the inlet tube should weep oil if the tractor is on?

FYI the loader and backhoe work OK, although the fluid might be a little low.

Any other thoughts?

Thanks.

 

[grsthegreat]

one quick question, do you have any rear remotes (hydraulic remote ports). the reason I'm asking, is if my tractor remote is set into detent or float position,. it can stop the other hydraulics from working.

what i had to do with my tractor was to loop a hose between both empty rear ports, so if i accidentally left the lever arm in detent position, i wouldn't deadhead the hydraulic pump.

that being said, if you dint have any rear remote ports, than I'm sure people here will tell you to get a hydraulic gage and check your pressures.

 

[eangler]

I don't believe so. I do have a backhoe but those hoses come from the block under the right foot. The manual mentioned something about rear remote and that system has three control levers behind the 3PH lever. I do not have that option.

 

[BeezFun]

Not familiar with that tractor, but there's usually a valve that controls the speed of the 3pt motion, if it's closed all the way there won't be any motion. Look down around where your heels would be when you're sitting on the tractor, probably something like a plastic or metal wheel a few inches in diameter.

 

[eangler]

Thanks. I have found the speed control and tried moving the arms in many different combinations to no avail.

I did find another member with a possibly similar problem who posted a while back. One reply on that thread mentioned that the Kubota is an "open" system. I also found another (unrelated to 3PH) post where someone said to connect the backhoe pressure and return hoses togtether when the BH is not mounted. I may try that at some point but I want to be sure nothing will blow up. Need to understand more.

 

[grsthegreat]

Thanks. I have found the speed control and tried moving the arms in many different combinations to no avail.

I did find another member with a possibly similar problem who posted a while back. One reply on that thread mentioned that the Kubota is an "open" system. I also found another (unrelated to 3PH) post where someone said to connect the backhoe pressure and return hoses togtether when the BH is not mounted. I may try that at some point but I want to be sure nothing will blow up. Need to understand more.

on an open system, if the hoses are not connected to an implement, the hydraulic fluids will not be able to work. also, you can damage the hydraulic pumps.
on my open system, when i disconnect say the log splitter, i put in a loop of hose between the output and return line, or nothing works.

 

[eangler]

OK, I must have some combination because the FEL works weather the backhoe is there or not, and when it's not I do not have to loop back the connection. Hmmm. I suppose this would all be documented in the service manual.

 

[PADan]

Check out pages 37 thru 41 of the Operator's Manual. You probably need to turn the Hydraulic Outlet Block Control Screw 90 degrees counterclockwise.

http://www.kubotabooks.com/AutoInde... L2900, L3300, L3600, L4200 owners manual.pdf

 

[RayCo]

While I doubt this is the problem, I suppose it can't help to mention it. When I got my first tractor with hydraulics, neither the front nor midpoint hitch would move. After trying to diagnose the hydraulic system without any experience, I stepped back and looked for a simpler solution. It turned out that the dash panel, where the hydraulic levers were, had shifted down over the years, and there simply wasn't enough clearance for the levers to go up all the way. After correcting this, everything worked as expected.

 

[eangler]

Check out pages 37 thru 41 of the Operator's Manual. You probably need to turn the Hydraulic Outlet Block Control Screw 90 degrees counterclockwise.

Well this did it. Thanks PADan. Turned the valve and the arms worked. The only problem is when I turn this to use the 3PH I can't use the loader. That's a little inconvenient. I will have to study it for a while to see if there is a way to fix it so I can use the loader and the 3 point.

 

[Jay4200]

Well this did it. Thanks PADan. Turned the valve and the arms worked. The only problem is when I turn this to use the 3PH I can't use the loader. That's a little inconvenient. I will have to study it for a while to see if there is a way to fix it so I can use the loader and the 3 point.

Your solution is NOT a solution, unless a 3pt power-beyond run isn't plumbed into your tractor.

Generally, a valved function is a 3-terminal connection: input (pressure input), output (return to sump), and power-beyond (pressure line to the next function). Only the last function is two-terminal (input and return to sump), which is usually either 3pt hitch -OR- the backhoe. My guess is that you have only two lines going to the backhoe.

My tractor (Kubota L4200) comes with a hydraulic block that drives the 3pt hitch. Turning a valve on the block diverts closes off the flow to the hitch, diverting it to an outlet hose (which goes to the 'IN' terminal for my loader). The loader's power-beyond outlet then is either returned to the 3pt to run that, or went back to the lines for the backhoe, at which point the 3pt was disabled. A hose had to be manually swapped to change from one to the other. As such, I had a choice of running the rear PB lines, or the 3pt hitch - but not both.

I ended up running one additional line from the back of the tractor to the 3pt hitch input. That way, I have the original PB from the loader and return (to sump) lines, and a new PB line to the 3pt. Connecting the two PB lines together enables the 3pt. When I connect the backhoe, I leave the 3pt PB line unconnected (now the backhoe is last in line). Now, any additional remote valves (with 3 terminal connections) can be placed in the back to run other 3pt hitch stuff - there 'IN' port being powered by the PB line from the loader, their PB output going to the 3pt, and their 'OUT' port going to the return line.

JayC

 

[eangler]

Hi JayC,

Your presumption is correct, there are only two lines to the backhoe. Note that I do not have a solution, but an inconvenience to solve. Not sure what my solution may be. You seem to have figured it out. Maybe there is another type of valve block available for me?

I am open to suggtions.