L2350DT Hydraulic Problem 3-PT Shakes

[TheOldHokie]

You can not "disconnect the feedback:" doing so will make the three point go all out of whack.

He needs to follow the WSM and adjust the feedback linkage properly.

By all means adjust away. Bit if that fails he can discinnect the feedback rod if he immobilizes the feedback lever. That should totally defeat feedback and allow him to have full control of spool mevement without interference from the feedback side.

Dan

 

[North Idaho Wolfman]

By all means adjust away. Bit if that fails he can discinnect the feedback rod if he immobilizes the feedback lever. That should totally defeat feedback and allow him to have full control of spool mevement without interference from the feedback side.

Dan

Not really, because the control for the three point and the feedback are interconnected in a seesaw connection, so they both affect the movement of the three point.
If you disconnect one or the other it has a negative adverse effect on the control.

@mcnuttja01, Is there a second lever by the three point control?
If there is, then it probably has draft control, that adds a whole other level of complexity to the issue.

 

[TheOldHokie]

Not really, because the control for the three point and the feedback are interconnected in a seesaw connection, so they both affect the movement of the three point.
If you disconnect one or the other it has a negative adverse effect on the control.

No. As long as the feedback end of the "seesaw" is fixed the spool is under direct control of the position control side.

Raise up spool is pushed in.
Push down spool is pulled out.
Let go spool centers to neutral.

 

[North Idaho Wolfman]

No. As long as the feedback end of the "seesaw" is fixed the spool is under direct control of the position control side.

Raise up spool is pushed in.
Push down spool is pulled out.
Let go spool centers to neutral.

If he Affixes the three point feedback in a fixed position it will cause the three point to stop moving at all the wrong locations, making troubleshooting an even bigger nightmare.
It will also cause the pump to go into a relief state which you can agree is not good.

 

[TheOldHokie]

If he Affixes the three point feedback in a fixed position it will cause the three point to stop moving at all the wrong locations, making troubleshooting an even bigger nightmare.

It eliminates feedback and it does not matter where the lift stops as ling as the shaking disappears when he commands up. If shaking stops wirh feedback disconnected something in feedback is the cause. It sumplifies things.

Dan

 

[mcnuttja01]

@mcnuttja01 do you have the WSM?
If not just ask.

Yes, I do have a PDF copy. I'll use it for the feed-back adjustment(s). Give me a few days to get back to it.

 

[PoTreeBoy]

I don't think this is it, but...
My BILs little Ford 1520 started the 3pt oscillating, it would drop to a point, then raise back up. A piece of his brake lining had gotten in the control valve. But his 3ph would drop with the engine off, this is easy to check.

 

[mcnuttja01]

Not really, because the control for the three point and the feedback are interconnected in a seesaw connection, so they both affect the movement of the three point.
If you disconnect one or the other it has a negative adverse effect on the control.

@mcnuttja01, Is there a second lever by the three point control?
If there is, then it probably has draft control, that adds a whole other level of complexity to the issue.

No "second" lever.

 

[mcnuttja01]

Yes, I do have a PDF copy. I'll use it for the feed-back adjustment(s). Give me a few days to get back to it.

No "second" lever.

I've looked at the WSM that I have and cannot locate a Feed Back Rod Adjustment. The feed-back rod is only mentioned in the the Description of how the Controls work on page 9-13.

 

[TheOldHokie]

I've looked at the WSM that I have and cannot locate a Feed Back Rod Adjustment. The feed-back rod is only mentioned in the the Description of how the Controls work on page 9-13.

You move the position control lever to full up and adjust the length of the rod to position the lift arms just under the point where you hear the relief valve open.

Dan

 

[mcnuttja01]

You move the position control lever to full up and adjust the length of the rod to position the lift arms just under the point where you hear the relief valve open.

Dan

I finally had a chance to find a manual and understand what I was adjusting.

With tractor running, I lift the ARMS, they raise to highest point and they begin to bounce and shake. I do not hear anything "change" like a valve opening and releasing pressure.

Then the bouncing begin and continues until I either lower the arms or close the lowering speed control under the seat.

That bouncing/jerking seems to cause a load on the motor also. Is it possible that the relief valve is not working and the pressure is continually rising??

 

[TheOldHokie]

I finally had a chance to find a manual and understand what I was adjusting.

With tractor running, I lift the ARMS, they raise to highest point and they begin to bounce and shake. I do not hear anything "change" like a valve opening and releasing pressure.

Then the bouncing begin and continues until I either lower the arms or close the lowering speed control under the seat.

That bouncing/jerking seems to cause a load on the motor also. Is it possible that the relief valve is not working and the pressure is continually rising??

Sounds like the bouncing is only happening at full (top) of lift. Is that correct?

If so I think the relief is working fine but the feedback linkage is not properly afjusted. Adjust the linlage fo reduce tje maximum lift on the arms until you find the point where the bouncing stops.

Dan

 

[mcnuttja01]

Sounds like the bouncing is only happening at full (top) of lift. Is that correct?

If so I think the relief is working fine but the feedback linkage is not properly afjusted. Adjust the linlage fo reduce tje maximum lift on the arms until you find the point where the bouncing stops.

Dan

It happens at any height of lift. All the way down, no problem. I read the manual and the advice earlier in this thread of adjusting the feedback linkage. The problem is, I never hear a "release" in pressure. It makes me think that the release valve is not working correctly??? Is that possible?

I am out of my element, having no experience with hydraulics......

 

[TheOldHokie]

It happens at any height of lift. All the way down, no problem. I read the manual and the advice earlier in this thread of adjusting the feedback linkage. The problem is, I never hear a "release" in pressure. It makes me think that the release valve is not working correctly??? Is that possible?

I am out of my element, having no experience with hydraulics......

The relief valve is only used in over pressure conditions and has nothing to do with normal operation of the lift arms. You have something else going on and it sure sounds like its feedback related.

Dan

 

[mcnuttja01]

The relief valve is only used in over pressure conditions and has nothing to do with normal operation of the lift arms. You have something else going on and it sure sounds like its feedback related.

Dan

I've attached a copy of the Hydraulic Circuit. I assume the FEEDBACK circuit is the UPPER part of ITEM 6.

I can make the problem stop by CLOSING the LOWERING Valve ITEM 7, which I assume stops the flow to ITEM 8, the LIFTING CYLINDER.

 

[TheOldHokie]

I've attached a copy of the Hydraulic Circuit. I assume the FEEDBACK circuit is the UPPER part of ITEM 6.

I can make the problem stop by CLOSING the LOWERING Valve ITEM 7, which I assume stops the flow to ITEM 8, the LIFTING CYLINDER.

The lowering valve restricts flow from the podition control valve back to tank.

When the position control valve is used to LOWER the arms it slowd the speed at which the arms drop. When fully closed the arms cannot be lowered.

The lowering speed valve should have no effect when you are raising the lift arms.

So do this. Lower the arms, fully clise tje lowering speed valve, and then raise tje lift. Does it shudder on tje way up?

Dan

 

[PoTreeBoy]

I've attached a copy of the Hydraulic Circuit. I assume the FEEDBACK circuit is the UPPER part of ITEM 6.

I can make the problem stop by CLOSING the LOWERING Valve ITEM 7, which I assume stops the flow to ITEM 8, the LIFTING CYLINDER.

When you close the lowering speed valve, do the arms slowly drop, or do they remain exactly where they were?

 

[RCW]

This is the feedback rod. got it from parts illustrations at https://apps.kubotausa.com/illustrated-parts/

 

[TheOldHokie]

When you close the lowering speed valve, do the arms slowly drop, or do they remain exactly where they were?

I think I know what you are thinking. I spent some time mulling thst possibilty over myself but it does not seem to account for all the symptoms.

I would really like an answer to my last question.

Dan

 

[mcnuttja01]

The lowering valve restricts flow from the podition control valve back to tank.

When the position control valve is used to LOWER the arms it slowd the speed at which the arms drop. When fully closed the arms cannot be lowered.

The lowering speed valve should have no effect when you are raising the lift arms.

So do this. Lower the arms, fully clise tje lowering speed valve, and then raise tje lift. Does it shudder on tje way up?

Dan

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