Kubota LA 480 Loader problem

[Joseph Razza]

My Kubota LA 480 bucket, put in the scoop or up position, will not move. It started to work slowly, and then stopped. I took apart the bucket pistons and they were fine. I pulled off the 3 quick connects and they seem good. If I move the stick just a little to the left to raise it, it will move very slow, but does go up. The down position works fine. If you move the lever full to left nothing but a few hoses jumping a little on the bottom. Move just a little and it will go up very slow. I'm starting to think it's in the the control Valve, because when it was in the down position, I took off the return line on the piston, and the bucket worked correctly. So I am thinking that the valve is not letting the fluid go back. The loader arms work fine. I did rebuild the bucket pistons about 3 years ago, and one of the seals was ground up a little so maybe some of the pieces got[in the control valve? I called a local Hydraulic repair company, I told him it was a Husco Valve, and he said forget about getting any parts for it. He said to take it off and he would take a look at it. ...and the 3 point hitch is in the correct position, the back hoe runs off the power take off with its own hydraulic system.
Does anybody have any suggestions? Thank, You Joe


https://www.dropbox.com/sh/o01sq1obw...iFHbClEQa?dl=0

Pictures on above link

 

[North Idaho Wolfman]

I could be wrong, but it sounds like you have PB and return lines crossed.

And your photo link is not valid or working.

 

[Joseph Razza]

The hose's have not been off the machine. It started about a week ago.
Only took off the lift cylinder hose return. I will try and fix my pictures.
Thank you. Joe

 

[North Idaho Wolfman]

Is it on an L2900 or a L3300?

Also looks like pictures of the valve and placement are needed as there is 2 different valves for that loader.

 

[Joseph Razza]

It's a L2900.


https://www.dropbox.com/sh/o01sq1obw8rlybu/AAATLglzDs9a4XFNiFHbClEQa?dl=0

photos

 

[lugbolt]

Quick coupler could be bad....or partially installed, plugged, etc.

3 point hitch feedback rod could be either out of adjustment, bent, broken missing, or the position control valve itself could be problematic. This is not common though...worth mentioning but not common. With a hoe on back, the lift lever should be all the way "down" no matter if it's a 3 point mount or a subframe mount. Down always with the hoe installed. "Up" or even somewhere in between up and down can sometimes pull hydraulic power from the rest of the hydraulic system. Usually hear the engine being loaded at idle too.

IIRC, under the tractor there is a slotted screwdriver head "valve" that's supposed to be turned to one position if a loader is installed, and then when the loader is removed, that valve is to be turned 90 degrees. Make sure it's one way or the other and not in between. IIRC there is a hose or two coming out of a block and that valve is built into it.

 

[Tooljunkie]

Also aux hydraulic controls need be in neutral, from your description one of the other tractor hydraulic circuits is engaged and cutting off power to loader.

 

[Joseph Razza]

Thanks for the responses. Please correct me if I am wrong. There are two quick connects that hook up under the tractor. I gather one brings fluid in and the takes the fluid back, since the loader arms are working fine, they are not blocked. Nothing has ever been removed from the tractor so all the lines are in the correct place. The backhoe is a separate unit with its own hydraulic tank; it runs off the power take off. It seems like the fluid has no place to go when I push the stick to the left. Like I said, if I move the stick very little it goes up very slow, to the right to dump is fine. Lift full to left it does not move. Keep thinking the Control Valve system is not working, keeping the fluid from returning, like a blockage. I am going out there today and remove the two lines from the control valve that run the bucket tilt, to see if there is anything in the lines. I will also move the control valve left and right to see if its flowing out of the valve, this should be a mess. Thank You..Joe

 

[North Idaho Wolfman]

Swap up and down and see if the problem swaps.

 

[Joseph Razza]

I tried that yesterday, and it would not move either way. So I switched them back.
I will be out there on Monday trying some more things. Thanks

 

[North Idaho Wolfman]

Sorry mis-worded that!

Swap up / down for roll and see if the problem follows.

 

[lugbolt]

Should be 3 hoses from the loader to the tractor, not 2. Open center system. There would be a pump hose, a return hose and a power beyond hose.

 

[Joseph Razza]

I have come to the conclusion that its in the control Valve.
I removed the line from the control valve that the fluid is suppose to go thru when you curl the bucket back. Once removed held line in a bucket, pushed the control to the left the bucket curled right back normally, as the fluid poured out of the house. So the fluid is stopping at the control block. I really don't want to work on the block, so I will be bringing it to a local Hydraulic company, said he would take a look at it on the machine and tell me what he thinks. Also he mentioned that the Husco Valve was not very easy to get parts for. He said there might another control valve he could put on if that was the problem, but I don't think I would want a different one on there.
The pic is of the hose marked no 1 that I took off and the bucket curled back fine. Thanks

https://www.dropbox.com/s/0rpb2mwwujvydhj/2017-02-17 13.21.06.jpg?dl=0