L2350DT Hydraulic Problem 3-PT Shakes

[TheOldHokie]

I lowered the arms, closed the speed valve, raised the lift, shudders at the top. Continues to shudder until I lowered the lift.

I created a short video here is a link (looks like you need to copy and paste) . https://photos.app.goo.gl/EiZz7dPyB4SCg3eu6

Once again, I do appreciate your time helping me with this. I am learning as I go......Jerry

Its quite clear that simething is blocking the pump circuit.

The bouncing at the top seems to be the position control valve either trying to lower the arms or relieve excess pressure. I say that because it stops bouncing when you close the lowering speed valve which cuts off all reverse flow from the cylinder. At that point the pump is fully deadheaded and either unloading via some relief or destroying itself.

Given the uncertaintity of your loader plumbing I am out of crystal ball answers.

As I said earlier I would start by completely eliminating the loader valve and proceed from there. Jumper it out of the circuit and make another video.

Dan

 

[PoTreeBoy]

1. In your first post you said it worked for a couple of years without issue. The 3ph raised and lowered normally, right? Did it always labor so much when raising the 3ph?
2. I've watched your video several times and at the end it appeared the 3ph stayed up with the valve closed. Correct?
3. In post #36, TheOldHokie asked for a specific test. Please do that.

 

[mcnuttja01]

1. In your first post you said it worked for a couple of years without issue. The 3ph raised and lowered normally, right? Did it always labor so much when raising the 3ph?
2. I've watched your video several times and at the end it appeared the 3ph stayed up with the valve closed. Correct?
3. In post #36, TheOldHokie asked for a specific test. Please do that.

Answers:
1) Yes it worked for a couple of years. I do not recall it laboring as much.
2) Yes, it did stay up, but with much less bounce.

3) I will do the test in the morning as suggested an Post the video.

 

[TheOldHokie]

1. In your first post you said it worked for a couple of years without issue. The 3ph raised and lowered normally, right? Did it always labor so much when raising the 3ph?
2. I've watched your video several times and at the end it appeared the 3ph stayed up with the valve closed. Correct?
3. In post #36, TheOldHokie asked for a specific test. Please do that.

The loader valve appears to be plumbed using tank for 3pt power beyond. If thats the case how can the loader work when the 3pt seems to be deadheaded. I had trouble seeing just how well the loader actually worked and a better demo of it might be helpful.

We can see that when the 3pt gets to the top it bounces and when the lowering valve is closed the bouncing stops. That suggests the bouncing is caused by something cycling and briefly opening to allow reverse flow from the singke acting lift cyliinder - possibly to tank. Then lift is commanded again and the 3pt jerks upwards again.

Closing the lowering valve prevents that reverse flow and the bouncing stops but the engine really loads up like its a complete hydraulic deadhead.

Something strange going on here and this needs to be broken into pieces that can be tested independently. Keep running it like it is and I suspect the pump is going to go to that great hydraulic heaven in the sky.

At this point my gùess is something in the position control feedback system is royally screwed up. The challenge is testing it.

Dan

 

[North Idaho Wolfman]

I lowered the arms, closed the speed valve, raised the lift, shudders at the top. Continues to shudder until I lowered the lift.

I created a short video here is a link (looks like you need to copy and paste) . https://photos.app.goo.gl/EiZz7dPyB4SCg3eu6

Once again, I do appreciate your time helping me with this. I am learning as I go......Jerry

The three point is going to keep doing what it's doing if you don't adjust the feedback linkage!
I'm really having a hard time understanding why you are not simply properly adjusting the linkage???
Did I miss where you adjusted it?

 

[TheOldHokie]

The three point is going to keep doing what it's doing if you don't adjust the feedback linkage!
I'm really having a hard time understanding why you are not simply properly adjusting the linkage???
Did I miss where you adjusted it?

I pretty much agree its position control related. But the 3pt is behaving very badly from top to bottom which leads me to think its more than a couple turns on an adjusting nut. A video showing the behavior of the feedback linkage as the 3pt is fully raused, bouncing at top, and then lowered would be informative.

Dan

 

[mcnuttja01]

The three point is going to keep doing what it's doing if you don't adjust the feedback linkage!
I'm really having a hard time understanding why you are not simply properly adjusting the linkage???
Did I miss where you adjusted it?

As I mentioned in another reply, I do not "hear" a change where it releases no matter where I move the adjustment. Also, I have about 50 threads of adjustment space. Since I couldn't hear a change I moved it about 10 threads and tried it again with no difference.

I will perform the following tests today with video.

1) Lower Arms, close lowering speed control, raise arms to top. Video
2) Video Feed Back Linkage while arms are raised to top.

Thanks again,

Jerry

 

[TheOldHokie]

As I mentioned in another reply, I do not "hear" a change where it releases no matter where I move the adjustment. Also, I have about 50 threads of adjustment space. Since I couldn't hear a change I moved it about 10 threads and tried it again with no difference.

I will perform the following tests today with video.

1) Lower Arms, close lowering speed control, raise arms to top. Video
2) Video Feed Back Linkage while arms are raised to top.

Thanks again,

Jerry

A really easy test is to set the feedback adjustment to its max and min. If the problem is something thst can be adjusted out one of those two settings will do it.

I also see draft control was an option on these tractors. If you have draft control the picture chages big time.

Dan

 

[mcnuttja01]

A really easy test is to set the feedback adjustment to its max and min. If the problem is something thst can be adjusted out one of those two settings will do it.

I also see draft control was an option on these tractors. If you have draft control the picture chages big time.

Dan

I did that from min to max with stoping and testing along the way.

 

[mcnuttja01]

I did that from min to max with stoping and testing along the way.

Here is a video of the Test with speed closed and lifting 3pt. Opened speed valve, 3 pt bouncing and video of feed back linkage....

New video by Jerry McNutt

photos.app.goo.gl

 

[TheOldHokie]

I did that from min to max with stoping and testing along the way.

And it behaved the same at all settings? If the position control linkage is connected and working the 3pt should have completely stopped lifting al one extreme.

Dan

 

[mcnuttja01]

A really easy test is to set the feedback adjustment to its max and min. If the problem is something thst can be adjusted out one of those two settings will do it.

I also see draft control was an option on these tractors. If you have draft control the picture chages big time.

Dan

 

[mcnuttja01]

No Draft Control. Acted the same across the adjustment range.

 

[TheOldHokie]

Here is a video of the Test with speed closed and lifting 3pt. Opened speed valve, 3 pt bouncing and video of feed back linkage....https://photos.app.goo.gl/yETgDVXYQqUf7DmV7

That does not look the sane as tje first video. In the first video it seemed like the 3pt struggled to raise and in this one ot looks smooth.

I cant see what the linkage is doing but it sure seems like the feedback is out of adjustment snd when the 3pt gets too high at the top something in the lift circuit opens and the lift drops then that something closes and it lifts again. Closing tje lower valve prevents the lft dropping and the bouncing stops.

With lowering speef valve open what happens when you move position contril lever part way up. Does it raise and hold at a lower position. Does it bounce?

Dan

 

[North Idaho Wolfman]

Your video was enlightening!
You likely have something wrong with the control valve.
Or more likely you have something wrong with the feedback linkage, like maybe a sheared roll pin on the front.
I say this because of the amount of throw that your doing with the control lever.
I'm 90% certain that your moving the lever too far back.
I will get confirmation on this shortly.

 

[mcnuttja01]

Your video was enlightening!
You likely have something wrong with the control valve.
Or more likely you have something wrong with the feedback linkage, like maybe a sheared roll pin on the front.
I say this because of the amount of throw that your doing with the control lever.
I'm 90% certain that your moving the lever too far back.
I will get confirmation on this shortly.

The external parts of the linkage are moving as the 3pt lifts and lowers. But, internal to the Control Valve I have no idea what's "moving" there. I will take a look at the diagram of the valve.

 

[TheOldHokie]

The external parts of the linkage are moving as the 3pt lifts and lowers. But, internal to the Control Valve I have no idea what's "moving" there. I will take a look at the diagram of the valve.

Real simple test. Raise the 3pt conyrol lever in stages,:

1/4 up and stop = what happens?
1/2 up and stop - what happens?
3/4 up and stop - what happens?

 

[mcnuttja01]

Real simple test. Raise the 3pt conyrol lever in stages,:

1/4 up and stop = what happens?
1/2 up and stop - what happens?
3/4 up and stop - what happens?

1st Time Up
- Open the Lowering Speed Control Valve
- 1/4 Stops and Holds position w/o Shaking
- same for all the others.
* The 3pt will not lower via the Position Control. I have to Open the Speed Control Valve. I opened until it dropped very slowly with the Position Control Level in the full down position.

2nd Time Up
- Will not hold position. Shakes when I raise further, but does raise.
- I closed the Lowering Speed Control Valve some and it raises without shaking. Will not lower via the Position Control, I have to Open the Lowering Speed Control.

 

[TheOldHokie]

1st Time Up
- Open the Lowering Speed Control Valve
- 1/4 Stops and Holds position w/o Shaking
- same for all the others.
* The 3pt will not lower via the Position Control. I have to Open the Speed Control Valve. I opened until it dropped very slowly with the Position Control Level in the full down position.

Everything as normal except your comment on the lowering speed valve. You start by saying valve is open and then you say it won't lower unless you open it. That is contradictory. Was the test run with the lowering speed valve open or closed? It should be run with the valve open.

2nd Time Up
- Will not hold position. Shakes when I raise further, but does raise.
- I closed the Lowering Speed Control Valve some and it raises without shaking. Will not lower via the Position Control, I have to Open the Lowering Speed Control.

Need a much fuller description of this test. What happens at each of the first three positions.

Dan

 

[Russell King]

Just to be sure you know about the 3PH speed control knob…

When you turn it fully one direction there is a locked position that will hold it in that position and it will not move down at all unless there is some leakage in that valve.

I agree with @North Idaho Wolfman in that your control lever moves a LOT more than I would expect it to move. Has it always moved that far back?