LA350 Loader will not go up, 3-pt fully functional

[1969SSCamaro]

I have a 1995 B2150HST. The 3 point is fully operational. The loader will not go up, but does go down. It also still rotates the bucket up/down. This all started after I let the hydraulic fluid get ridiculously low: almost 4 Qts low. Below are things I have checked so far, but I am a novice at best. I've had the tractor for 10 years.
- filled with fluid, started it for a few minutes and then added more. I've checked it several times and the fluid level is good.
- loosen air bleeding bolt on the Hydraulic Block Type Output
- remove and reconnect all quick disconnect connections
- removed flow priority valve and inspect/verify spring is functional
- checked position of directional valve (strangely enough it is fully CCW, which is incorrect according to the manual? When in the correct position, nothing on the bucket works. I have never ever adjusted this until today when this problem started.

see attached photos. The tractor came with an auxilliary control valve - see photo of connection diagram. Any ideas what could cause this? I thought about bypassing the AUX valve, but since the bucket rotates up/down, that doesn't seem to be the problem? maybe the relief valve in the loader control valve???

Thanks for any help that can be provided.
Greg

 

[TheOldHokie]

This sounds suspiciously like a priblem we discussed a few months agi.

Your diagram shows three connections to the loader valve. One is labeled IN and the other is labeled OUT. What is the third connection and why is there no power beyond shown on the loader valve?

Dan

 

[1969SSCamaro]

This sounds suspiciously like a priblem we discussed a few months agi.

Your diagram shows three connections to the loader valve. One is labeled IN and the other is labeled OUT. What is the third connection and why is there no power beyond shown on the loader valve?

Dan

Hi Dan,
There are few labels on most of these valves so I am unfortunately unable to provide much more. But, the 3rd connection is the "drain pipe" (based on names used in the Kubota service manual). The power beyond the loader are the 4 output/inputs to operate the bucket.

 

[TheOldHokie]

Hi Dan,
There are few labels on most of these valves so I am unfortunately unable to provide much more. But, the 3rd connection is the "drain pipe" (based on names used in the Kubota service manual). The power beyond the loader are the 4 output/inputs to operate the bucket.

The loader valve should have three connections in addition to the four work ports for the loader cylinders:

1. Pump pressure IN from the hydraulic block
2: Power beyond pressure out to IN on auxiliary control valve.
3) Tank return to hydraulic block.

One of the ports on the loader valve is power beyond just like you show on the auxiliary valve.

Dan

 

[1969SSCamaro]

The loader valve should have three connections in addition to the four work ports for the loader cylinders:

1. Pump pressure IN from the hydraulic block
2: Power beyond pressure out to IN on auxiliary control valve.
3) Tank return to hydraulic block.

One of the ports on the loader valve is power beyond just like you show on the auxiliary valve.

Dan

Dan, my apologies but I don't have the knowledge to properly answer your question.
Greg

 

[TheOldHokie]

Dan, my apologies but I don't have the knowledge to properly answer your question.
Greg

Ordibarily the primary suspect would be one of the quick couplers. What is bothering me is your comment that it worked previously but the hydraulic block selector valve was in the wrong position. That sets off alarm bells.

So lets start with the basics. Is the selector valve now in the correct position and the loader curls and dumps but won't lift?

Dan

 

[1969SSCamaro]

Ordibarily the primary suspect would be one of the quick couplers. What is bothering me is your comment that it worked previously but the hydraulic block selector valve was in the wrong position. That sets off alarm bells.

So lets start with the basics. Is the selector valve now in the correct position and the loader curls and dumps but won't lift?

Dan

The selector valve has been in the wrong position for 10 years. When I turn it fully CW, nothing works on the loader. This is puzzling to me as well?

 

[TheOldHokie]

The selector valve has been in the wrong position for 10 years. When I turn it fully CW, nothing works on the loader. This is puzzling to me as well?

Which leads me to believe the loader valve is not plumbed correctly. That may not be the cause of your current problem but correcting the plumbing would be my first priority.

Dan

 

[1969SSCamaro]

Which leads me to believe the loader valve is not plumbed correctly. That may not be the cause of your current problem but correcting the plumbing would be my first priority.

Dan

I wonder of the addition of the Auxilliary valve controller is the reason??? But I can say with certainity it has worked for 10 years with the valve fully CCW and won't work in the full CW position.

 

[TheOldHokie]

I wonder of the addition of the Auxilliary valve controller is the reason??? But I can say with certainity it has worked for 10 years with the valve fully CCW and won't work in the full CW position.

According to your diagram the aux valve is plumbed fine. I dont doubt it worked as is but it aint right.

Post a good top view picture of the loader valve - perhaps we can identify the connections a bit better.

Dan

 

[1969SSCamaro]

According to your diagram the aux valve is plumbed fine. I dont doubt it worked as is but it aint right.

Post a good top view picture of the loader valve - perhaps we can identify the connections a bit better.

Dan

Hi Dan, see attached photos of control valve.
Thanks,
Greg

 

[TheOldHokie]

Hi Dan, see attached photos of control valve.
Thanks,
Greg

Where does the hose marked A in this picture go?

Dan

 

[1969SSCamaro]

Where does the hose marked A in this picture go?

Dan

View attachment 83028

It goes to the IN port of the Auxilliary Control Valve.

 

[TheOldHokie]

It goes to the IN port of the Auxilliary Control Valve.

Good. I believe that is the power beyond port on the loader valve. Lets try the other two. Where do ports B and C go?

Dan

 

[1969SSCamaro]

Port B goes to the output of the block type output (Port A in the photo showing the blockbtyoe output)
Port C goes to the "pipe drain" of the block type output (Port C in the photo)

 

[1969SSCamaro]

With photo

 

[1969SSCamaro]

Dan,
i found at least one problem; i removed the spool cap and it was packed full of dirt/grease to the point the valve was not engaging. the photo shows the cleanded-up spool cap. But it seems like it is raising the bucket slower than before. There was a small ball bearing in the bottom of spool cap which I assume was there to limit how far it could move. i might try removing it to see if it helps, but first i need to purchase some more fluid. I will also need to apply more grease to the inside of the spool cap.

 

[TheOldHokie]

Dan,
i found at least one problem; i removed the spool cap and it was packed full of dirt/grease to the point the valve was not engaging. the photo shows the cleanded-up spool cap. But it seems like it is raising the bucket slower than before. There was a small ball bearing in the bottom of spool cap which I assume was there to limit how far it could move. i might try removing it to see if it helps, but first i need to purchase some more fluid. I will also need to apply more grease to the inside of the spool cap. View attachment 83080

I suspect the ball bearing is part of the float detent. It may have dislodeged from its proper position and jammed the spool.

I looked at your other pictures and it appears the loader valve is plumbed correctly. Are you SURE it does not work with the direction control valve turned fully clockwise? I can't see how it could work at all in the pass thru position.

Dan

 

[1969SSCamaro]

I suspect the ball bearing is part of the float detent. It may have dislodeged froiim its proper position and jammed the spool.

I looked at your other pictures and it appears the loader valve is plumbed correctly. Are you SURE it does not work with the direction control valve turned fully clockwise? I can't see how it could work at all in the pass thru position.

Dan
I removed the ballbearing and greased the spool cap and it's working great! i checked the control valve again and noticed that it rotates a half turn; I thought it only rotated a 1/4 turn. The loader works as it should with the valve in the middle position. If I go max CCW or CW, the bucket will not raise. Not sure if it's supposed to be a half turn? Thank you very much for your help and patience, it is greatly appreciated. Have a great weekend.
greg

 

[TheOldHokie]

That ball bearing did not materialize out of thin air. Is the float detent working?

Dan