3 POINT HITCH INOP

[TheOldHokie]

So I got back to the tractor. I have flow to and from the laolder block in the side of the 3 point. Still no movement. But I did notice depending on the position of the lift arms if I lift them by hand the three point lift handle will be pushed foreword by the linkage coming out of my three point housing. It is not strong but will push it foreword. And the power beyond line from the loader valve to the block is getting warm so there is flow.

Your 3pt lift arms are mechanically connected to the lever by teh position control feedback linkage. That is why the lever moves when you liftthe arms and has nothing to do with hydraulics.

I take it you did not disconnect any of the lines to visually verify flow?

Dan

 

[TOMTRUTH]

So I got back to the tractor. I have flow to and from the laolder block in the side of the 3 point. Still no movement. But I did notice depending on the position of the lift arms if I lift them by hand the three point lift handle will be pushed foreword by the linkage coming out of my three point housing. It is not strong but will push it foreword. And the power beyond line from the loader valve to the block is getting warm so there is flow.

Fluid pressure is pushing on it.

 

[TheOldHokie]

Fluid pressure is pushing on it.

Can you tell me how fluid pressure is pushing on that lever? Here is the position control feedback linkage. Unless you have disconnected it when you manually raise or lower the lift arms it pushes on the lever.

Dan

 

[TOMTRUTH]

Can you tell me how fluid pressure is pushing on that lever? Here is the position control feedback linkage. Unless you have disconnected it when you manually raise or lower the lift arms it pushes on the lever.

Dan

View attachment 87584

So when I put the lever in lift or any position but the most foreword, if I lift the arms while the tractor is running there is a slight pressure that pushes the lever foreword, I can easily hold it in position. It’s not like it is sticking or being pushed at all mechanically by the rod connected to the 3 point arm. I can still flip the arms up and down at will. But if I lift them while the tractor is running the lever is slowly pushed foreword. I disconnected the link arm at bracket 210 and moved it full travel with no result in any movement of the arms as they should.

Tom.

 

[TheOldHokie]

So when I put the lever in lift or any position but the most foreword, if I lift the arms while the tractor is running there is a slight pressure that pushes the lever foreword, I can easily hold it in position. It’s not like it is sticking or being pushed at all mechanically by the rod connected to the 3 point arm. I can still flip the arms up and down at will. But if I lift them while the tractor is running the lever is slowly pushed foreword. I disconnected the link arm at bracket 210 and moved it full travel with no result in any movement of the arms as they should.

Tom.

You are spinning your wheels and going nowhere with this line of inquiry. I will ask just one more time. Have you disconnected the return pipe at the outlet block and verified you are getting a strong constant oil flow when the tractor is running? Not just a trickle - a garden hose of oil. So much oil that you need to put some tube on that line and run it back into the filler.

Dan

 

[fooldog01]

I was waiting to see if the OP came back before I asked a question but it looks like they may not. My dad got a new-to-him L2350DT with an LB400 loader like this and I am trying so hard to help him get the loader going. Everything I have found online shows a different control valve and block than what we have. The OP is the first person I have seen with the same original valve and block as us. The valve appears to be a Danfoss 1625AH but I cant find any information about it online. Its like it doesnt exist anywhere other than in an extra diagram on Messicks, which doesnt help at all. Any idea why there would be 2 totally different designs? More importantly would you happen to have any suggestions for getting my hands on some technical info on the valve? I am tryign to contact QCC, who bought Danfoss Fluid Power and is supposed to handle tech, but I am not havign any luck. I will make a new thread if I need to. Thanks for your help!

 

[TheOldHokie]

I was waiting to see if the OP came back before I asked a question but it looks like they may not. My dad got a new-to-him L2350DT with an LB400 loader like this and I am trying so hard to help him get the loader going. Everything I have found online shows a different control valve and block than what we have. The OP is the first person I have seen with the same original valve and block as us. The valve appears to be a Danfoss 1625AH but I cant find any information about it online. Its like it doesnt exist anywhere other than in an extra diagram on Messicks, which doesnt help at all. Any idea why there would be 2 totally different designs? More importantly would you happen to have any suggestions for getting my hands on some technical info on the valve? I am tryign to contact QCC, who bought Danfoss Fluid Power and is supposed to handle tech, but I am not havign any luck. I will make a new thread if I need to. Thanks for your help!

Kubota used many differ rent designs and suppliers for their loaders. Here is the parts page for the L2350 hydraulic outlet option shown boxed in red. It took me a while to find it and understand where it actually fits on the top cover. The one on the OP's tractor (and apparently yours) is different. The operator's manual for the tractor and/or loader typically describes its use but the L2350 manual does not. If you study the pump plumbing and think about it for a moment the one in the parts diagram would be ahead of the PS flow divider which would not be a very good idea. So MAYBE it was only used on tractors with manual steering and there was a different block for tractors with PS.

You will find limited support for the old control valves. In general, if the valve is defective its more cost effective to replace them.

The loader supply system is quite simple. What exactly is your problem?

Dan

 

[fooldog01]

Kubota used many differ rent designs and suppliers for their loaders. You will find limited support for the old control valves. In general, if the valve is defective its more cost effective to replace them.

The loader supply system is quite simple. What exactly is your problem?

Dan

This may be a bit difficult for me to explain because I am not versed on this stuff but there are a few things.

As for the actual symptoms, the loader will go up just a bit and then stops and the engine loads up from pump resistance. It wont go down until you turn the engine off. Then it will go down. Same behavior for tilt.

I dont know if we need a power beyond sleeve. It doesnt seem to have one but I could just be stupid and not know what I am looking at.

A small metal orifice thing fell out when my dad was disassembling the valve to inspect it. Im not entirely sure where that needs to go.

There is an IN and an OUT marking for the ports that aim downward. There is an unmarked port with an elbow on the front/top beside the loader hose connections. I am not 100% sure which one goes where. We identified the IN because it pumps a full stream of fluid constantly. It is coming from the hydraulic block on the side The unmarked port with the elbow was returning back to the block and there was no fluid coming from it. We havent checked the OUT hose that goes to the tank return. We ran out of time but that is next. We also dont know if the block connections are designated in and out or if it doesnt matter because they are unmarked.

The previous owner had monkeyed with a bunch of stuff, including blowing the engine up by having the timing totally out of whack, so we cant trust the way it was hooked up and the colored markings are gone from everything. I did find a diagram on Messicks that let me identify the correct routing for the hoses going to the cylinders though, so that should be correct.

Sorry for the long winded reply.

 

[TheOldHokie]

This may be a bit difficult for me to explain because I am not versed on this stuff but there are a few things.

As for the actual symptoms, the loader will go up just a bit and then stops and the engine loads up from pump resistance. It wont go down until you turn the engine off. Then it will go down. Same behavior for tilt.

I dont know if we need a power beyond sleeve. It doesnt seem to have one but I could just be stupid and not know what I am looking at.

A small metal orifice thing fell out when my dad was disassembling the valve to inspect it. Im not entirely sure where that needs to go.

There is an IN and an OUT marking for the ports that aim downward. There is an unmarked port with an elbow on the front/top beside the loader hose connections. I am not 100% sure which one goes where. We identified the IN because it pumps a full stream of fluid constantly. It is coming from the hydraulic block on the side The unmarked port with the elbow was returning back to the block and there was no fluid coming from it. We havent checked the OUT hose that goes to the tank return. We ran out of time but that is next. We also dont know if the block connections are designated in and out or if it doesnt matter because they are unmarked.

The previous owner had monkeyed with a bunch of stuff, including blowing the engine up by having the timing totally out of whack, so we cant trust the way it was hooked up and the colored markings are gone from everything. I did find a diagram on Messicks that let me identify the correct routing for the hoses going to the cylinders though, so that should be correct.

Sorry for the long winded reply.

You are doing pretty good explaining something you do not understand. Keep that up and we will get you straightened out.

Lets start with the loader valve. I have labeled the ports in the picture you provided based on my best guess, . Pressure in comes from the hydraulic ooutlet block, tank return goes to the sump filler cap, and power beyond goes back to the hydraulic outlet block. Without documentation on the valve its not possible to know for sure if a power beyond port sleeve is needed There is not one visible so if its missing power beyond is exactly the same a s tank. The orifice thing bothers me,

Some simple experimentation will answer those questions.

The hydraulic outlet block has an IN and an OUT port. As soon as the tractor is started the OUT port will start spewing oil. That definitly goes to the IN port on your valve. A picture of that block would be informative.

 

[fooldog01]

Thank you! It may be Monday before I can get pictures or do more testing but as soon as I do I will report back.

 

[TheOldHokie]

Thank you! It may be Monday before I can get pictures or do more testing but as soon as I do I will report back.

Sure. Rather than hijack this thread i will start a private conversation.

Dan

 

[TOMTRUTH]

You are spinning your wheels and going nowhere with this line of inquiry. I will ask just one more time. Have you disconnected the return pipe at the outlet block and verified you are getting a strong constant oil flow when the tractor is running? Not just a trickle - a garden hose of oil. So much oil that you need to put some tube on that line and run it back into the filler.

Dan

View attachment 87867

I get like a garden hose on 20% or so. Will shoot about 2-4 inches out of tube then drops to ground. Fill a beer can in about 5 sec

 

[TheOldHokie]

I get like a garden hose on 20% or so. Will shoot about 2-4 inches out of tube then drops to ground. Fill a beer can in about 5 sec

Just for my edification which of these lines did you disconnect - A or B?

One last external check would be to hook a pressure gauge to that line and verify you have pressure as well as flow but the loader works so it seems unlikely that you would not.

If your flow is constant and not just a spurt the problem would seem to be inside the lift cover. Diagnosis oso of that requires removal of the cover. Some possibilities:

Control linkage disconnected from spool

Inoperable/damaged piston or piston rod disconnected

Damaged or inoperable control valve

 

[TOMTRUTH]

I get flow at the supply/return lines at loader the block on the 3 point. The return is about a gallon a minute or so. I’m going to replace the whole power beyond rubber lines and coupler from the loader valve to the block on the 3 point. Seems restricted. Tom

 

[TheOldHokie]

I get flow at the supply/return lines at loader the block on the 3 point. The return is about a gallon a minute or so. I’m going to replace the whole power beyond rubber lines and coupler from the loader valve to the block on the 3 point. Seem s restricted. Tom

I am trying real hard to be as clear and unambiguous as possible but we are not communicating clearly.

Your loader valve has THREE connections that matter here:

1. The pressure supply line coming from the outlet block on the side of the hydraulic top cover. That is either line A or line B in my picture. Which is it - A or B?
2. The other line is the power beyond line that supplies pressure to the 3pt. Is that line A or B? To avoid any confusion and ambiguity please call that line power beyond - it is not the return line.
3. The return line goes to the filler cap for the sump. It is a low pressure tank return and there should be ZERO flow in that line. You have never posted a picture of that line and if there is flow coming out of it something is wrong in the plumbing.

When you disconnect the power beyond line at the outlet block you should get a STEADY stream of oil coming out of the end of the steel tube. As long as it is a steady stream the lift arms will still come up. The faster the flow the faster the arms will raise. The slower the flow the slower the arms will raise. A good test of that line is to slip a piece of vinyl tube over the open end and run that tube back to the sump filler. Start the tractor and watch the flow. If it pumps oil constantly for a minute it is good to go.

Dan

 

[TOMTRUTH]

Line B comes back from the power beyond port on the loader control valve. It flows constantly when the tractor runs which it didn’t until I changed the springs in the loader control valve. One was bent. Flows about a gallon a minute at idle. So my further issue is inside my 3 point I think.

 

[TheOldHokie]

Line B comes back from the power beyond port on the loader control valve. It flows constantly when the tractor runs which it didn’t until I changed the springs in the loader control valve. One was bent. Flows about a gallon a minute at idle. So my further issue is inside my 3 point I think.

If you increase the engine RPM to 2000 plus the power beyond should be flowing a lot more tha 1 GPM. More like 5 GPM.

I am averse to work so I would still do a pressure test on that power beyond line (at the block) before removing the hydraulic cover.

Dan