L2900 - 3 point arms have no lift, drop like rocks, need help troubleshooting

[Tom Hutchins]

Hello, I’m new to this forum also new to Kabota tractors, I have a late 90s L 2900 Kabota

Been a great tractor so far had it for about a year

The arms on the three-point hitch have given away. They just dropped to the ground. I can pick them up. Let them go. They drop straight down. There’s no catch at all.

I had gotten very low on hydraulic oil, so I filled it. I’ve also went ahead and replaced the filter.

Trying to do research on what this could be and getting turned around

I’ve also checked the knob that controls how much it drops and that’s fine, no matter what direction I turn it. It doesn’t change the outcome.

After I filled it out, I tried cycling the control arm up and down multiple times, and that didn’t work

The bucket still works just fine and I’ve cycled through that as well

does anyone have a good suggestion on what to check next?

 

[Russell King]

Ok we could probably help if you had a Kubota but I don’t know much about Kabota tractors!

Now seriously I assume that you have some problems with the hydraulic circuit that feeds the three point control valve so I will make some troubleshooting suggestions.

You state that the FEL is working correctly and I assume that the same pump for the FEL provides fluid to the rear hydraulics as well. So I am assuming that the pump is still making fluid move through the system but something is blocking it.

So you probably have some quick disconnects involved in the FEL valve to allow for easier removal of the FEL. There are probably 7 hoses on the FEL valve (4 connecting to the cylinders on the FEL and 3 connecting to the tractor. It is the three connections to the tractor that you need to investigate. The easiest thing to do is to disconnect all three hoses as if you are removing the FEL (I am assuming the valve is removed with the FEL). Disconnect them one at a time so you don’t get confused where they go. Clean both ends and then connect them back together and be sure they are well connected. Then move to the second one and repeat, then the third.

You are really not worried about the Tank Return line or the power in line but you may not be able to identify them so just do all three. The PB line should provide flow back to the three point control valve. I think it may have a bad connection.

After reconnecting the last line start the tractor and test the three point control valve and see if the arms are now moving. If not come back and tell us that it is still giving you problems. And please describe your hydraulic system in more detail (what FEL is installed, are there any other valves on the tractor?, …)

 

[whitetiger]

Does your tractor have either rear remotes or a backhoe connection?

 

[Tom Hutchins]

Ok we could probably help if you had a Kubota but I don’t know much about Kabota tractors!

Now seriously I assume that you have some problems with the hydraulic circuit that feeds the three point control valve so I will make some troubleshooting suggestions.

You state that the FEL is working correctly and I assume that the same pump for the FEL provides fluid to the rear hydraulics as well. So I am assuming that the pump is still making fluid move through the system but something is blocking it.

So you probably have some quick disconnects involved in the FEL valve to allow for easier removal of the FEL. There are probably 7 hoses on the FEL valve (4 connecting to the cylinders on the FEL and 3 connecting to the tractor. It is the three connections to the tractor that you need to investigate. The easiest thing to do is to disconnect all three hoses as if you are removing the FEL (I am assuming the valve is removed with the FEL). Disconnect them one at a time so you don’t get confused where they go. Clean both ends and then connect them back together and be sure they are well connected. Then move to the second one and repeat, then the third.

You are really not worried about the Tank Return line or the power in line but you may not be able to identify them so just do all three. The PB line should provide flow back to the three point control valve. I think it may have a bad connection.

After reconnecting the last line start the tractor and test the three point control valve and see if the arms are now moving. If not come back and tell us that it is still giving you problems. And please describe your hydraulic system in more detail (what FEL is installed, are there any other valves on the tractor?, …)

 

[Tom Hutchins]

lol!! Darn voice to text!

I checked those three hoses. They seem clear.

I added some photos to Help

thank you!!

 

[Tom Hutchins]

Does your tractor have either rear remotes or a backhoe connection?

No, it does not appear to

 

[Russell King]

The upper left hose in picture 7542 above is bent in too small of a radius and the ID is probably closed to almost nothing.

If it was me I would get that hose in a much straighter shape and see if that improves your performance.

Also between the two hoses in that same picture is a selection valve that is turned one direction or the other (vertical or horizontal) depending on if the FEL is installed or not. I don’t know which is correct for your tractor but you need to get that from the operators manual and confirm that it is correct direction.

 

[Russell King]

Also, how has the operation changed over the time you had the tractor? Was it a slow and steady change or a sudden change?

 

[North Idaho Wolfman]

Are these two actually connected?
Looks like a roll pin is missing.

 

[Tom Hutchins]

The upper left hose in picture 7542 above is bent in too small of a radius and the ID is probably closed to almost nothing.

If it was me I would get that hose in a much straighter shape and see if that improves your performance.

Also between the two hoses in that same picture is a selection valve that is turned one direction or the other (vertical or horizontal) depending on if the FEL is installed or not. I don’t know which is correct for your tractor but you need to get that from the operators manual and confirm that it is correct direction.

hose was straight before issues and I put back after this picture was taken. Still same operation

I will look at manual about selection valve, I assume it’s fine since FEL and 3pt lift worked fine before but I’ll
Double check

 

[Tom Hutchins]

Are these two actually connected?
Looks like a roll pin is missing.

View attachment 177472

Sorry, forgot to put pin back in when I was looking into this. I can’t get it to slide back on. But this seems to be moving correctly, has about a 30degree turn for raising and lowering operation.

 

[Tom Hutchins]

Also, how has the operation changed over the time you had the tractor? Was it a slow and steady change or a sudden change?

It seems sudden because I wasn’t even using it at the time it went really limp however it could’ve been slowly going

And I didn’t notice that the hydraulic fluid was getting low and it got pretty low as in couldn’t see it in the site class when this suddenly failed and easily put in full bottle to get level to three-quarter site glass

 

[Russell King]

Okay now it is time to get into some flow and pressure diagnosis steps.

First I just want to clarify that the upper lift arms will always fall (limply) if there is no hydraulic fluid in the lift cylinder (located near where the speed control knob enters the case).

I believe you should try to find a Work Shop Manual and follow the steps in troubleshooting this and you would resolve it sooner than getting help here. You may be able to get it at this Site.

But starting at the pump there should be flow through the Nuetral circuit of the tractor. That flow eventually goes to through the three point valve and dumps back to the sump where it was before. So at the block on the tractor shown below, read your operators manual and find out what the three hoses do and identify them with some markings. There should be some flow out to implement, flow back from implement and a low pressure tank return from the implement. All three should be connected to the FEL valve. You said the quick disconnects on the tractor are clean but the two shown in the picture below are dirty on the exterior which is normal but not cleaned.



You can test the pressure by connecting a 3000 PSI gauge to one of the hoses on the FEL hoses to a cylinder and operating that valve that controls that cylinder movement. Run tractor at higher RPMS and read pressure then turn tractor off and return to normal operation condition,

You can test the flow out of the FEL valve before you remove it by taking the power beyond hose loose from the tractor end, removing the quick disconnect end from the hose (if there is one), putting that end into a clean bucket or (better) into the fill port of the transmission. Start tractor and see if there is flow out of that hose.

The first thing I would do is to remove the FEL hydraulic circuit so the tractor thinks there is no FEL installed. You don’t have to physically remove the FEL just the hydraulic circuit. Turn that valve between the hoses (screw looking thing that is vertical above) to correct position for when no external implements are installed. Then start tractor and test the three point hitch control. If it works then you know that the FEL hydraulic circuit is causing the problem, if it doesn’t work then you know it is something in the three point hitch circuit.

 

[netspyder]

maybe a good question to ask is where are you losing hydraulic fluid? i'm not sure about yours, but if there's nothing showing in the sight glass on mine it'd easily take a whole 5 gallon bucket to fill. hydraulic oil isn't cheap - if you have a leak then i'd look to find and fix that for sure.

 

[TheOldHokie]

Sorry, forgot to put pin back in when I was looking into this. I can’t get it to slide back on. But this seems to be moving correctly, has about a 30degree turn for raising and lowering operation.

The loader supplies the 3pt. If you are sure the lift control lever is working check the return connections from the loader.

Dan

 

[Tom Hutchins]

Okay now it is time to get into some flow and pressure diagnosis steps.

First I just want to clarify that the upper lift arms will always fall (limply) if there is no hydraulic fluid in the lift cylinder (located near where the speed control knob enters the case).

I believe you should try to find a Work Shop Manual and follow the steps in troubleshooting this and you would resolve it sooner than getting help here. You may be able to get it at this Site.

But starting at the pump there should be flow through the Nuetral circuit of the tractor. That flow eventually goes to through the three point valve and dumps back to the sump where it was before. So at the block on the tractor shown below, read your operators manual and find out what the three hoses do and identify them with some markings. There should be some flow out to implement, flow back from implement and a low pressure tank return from the implement. All three should be connected to the FEL valve. You said the quick disconnects on the tractor are clean but the two shown in the picture below are dirty on the exterior which is normal but not cleaned.

View attachment 177477

You can test the pressure by connecting a 3000 PSI gauge to one of the hoses on the FEL hoses to a cylinder and operating that valve that controls that cylinder movement. Run tractor at higher RPMS and read pressure then turn tractor off and return to normal operation condition,

You can test the flow out of the FEL valve before you remove it by taking the power beyond hose loose from the tractor end, removing the quick disconnect end from the hose (if there is one), putting that end into a clean bucket or (better) into the fill port of the transmission. Start tractor and see if there is flow out of that hose.

The first thing I would do is to remove the FEL hydraulic circuit so the tractor thinks there is no FEL installed. You don’t have to physically remove the FEL just the hydraulic circuit. Turn that valve between the hoses (screw looking thing that is vertical above) to correct position for when no external implements are installed. Then start tractor and test the three point hitch control. If it works then you know that the FEL hydraulic circuit is causing the problem, if it doesn’t work then you know it is something in the three point hitch circuit.

All right, thank you for the references. I appreciate that link.

I tried to bypass screw, and the three-point still does not work. It does not raise or lower.

I will work through the flow diagram



I should also mention that I don’t hear anything engaging or the tractor bogging down or anything like that when I move the lever. I’m not sure I did before but some research I did, suggested that might happen or I might be able to put my hand on the housing and feel things moving or engaging. And I don’t.

It does seem like something broke, but I can also see that the flow is not pressurizing

really appreciate your time on this. This is very helpful.

 

[TheOldHokie]

All right, thank you for the references. I appreciate that link.

I tried to bypass screw, and the three-point still does not work. It does not raise or lower.

I will work through the flow diagram



I should also mention that I don’t hear anything engaging or the tractor bogging down or anything like that when I move the lever. I’m not sure I did before but some research I did, suggested that might happen or I might be able to put my hand on the housing and feel things moving or engaging. And I don’t.

It does seem like something broke, but I can also see that the flow is not pressurizing

really appreciate your time on this. This is very helpful.

Turning the screw and testing the 3pt with the loader attached is not definitive. Disconnect the loader hoses and repeat the test.

Is the loader working at full speed and power?

Dan