Strange loader problem

[Ben755]

I originally posted my question in the wrong forum section - didn't realize that it had a hydraulics section. The problem is my tractor FEL won't lower. When I push the joystick controller forward to lower the bucket, the bucket raises instead of lowering. The other functions, tilting and raising, work ok. The loader manufacturer (Koyker) hasn't seen this problem before. They think that maybe the return line from the FEL could be blocked or have back pressure, but don't think that the problem is with the controller. Has anyone experienced this problem ? Any thoughts on the cause ?

 

[Rosher18]

I have this problem on my Kubota L185DT occasionally, but that is because I push the loader into float mode with my heavy box blade on the 3PT. The pressure feeds to the 3PT but doesn't lift it because it's easier to lift the FEL. If the 3PT isn't at the position commanded by the lever, and I ask the loader to move down, the tractor will strain and the loader won't move down smoothly or at all. You may be on the right track regarding back pressure or blockage.

 

[Rustyiron]

I don't see how you could all of a sudden have a line blockage. My guess would be the valve itself has problems.
Can you ID the right hose for the "lower" function, remove it from the valve or where it returns to the tractor and then see if the loader arms lower?

 

[topbuilder]

Make sure one of your quick disconnects has not separated.

 

[mrfu]

I had a similar problem and it was the quick disconnects. I put some older ones I had on and it went away.
Tom

 

[Ben755]

I've checked the disconnects and the're ok. I'm thinking of removing the FEL return hose and temporarily routing it directly to the fluid sump. When I start the engine and try to move the bucket, fluid should pour into the sump.

 

[oldnslo]

I originally posted my question in the wrong forum section - didn't realize that it had a hydraulics section. The problem is my tractor FEL won't lower. When I push the joystick controller forward to lower the bucket, the bucket raises instead of lowering. The other functions, tilting and raising, work ok. The loader manufacturer (Koyker) hasn't seen this problem before. They think that maybe the return line from the FEL could be blocked or have back pressure, but don't think that the problem is with the controller. Has anyone experienced this problem ? Any thoughts on the cause ?

For clarity of information.

Does the loader raise when you move the joystick to both the lower and raise positions?

If return line from the FEL valve is blocked none of the functions would operate properly.

 

[rdinatal]

Did you take the FEL off and swap the hoses?

-R

 

[mrfu]

mine looked fine also I think what happened was there was enough loose oil in the female end to keep them from coupling. One of the things I did was switch the hoses around so curl was up and down etc.
I kept having the same problem, the old disconnects had a spud instead of ball to open them so maybe didn't need as tight a tolerance.
Tom

 

[Ben755]

For clarity of information.

Does the loader raise when you move the joystick to both the lower and raise positions?

If return line from the FEL valve is blocked none of the functions would operate properly.

Yes, the loader raises when I push forward on the joystick and when I pull back on it.

 

[oldnslo]

Ben755
First silly question, I presume the FEL operated correctly at some point? Is this correct?

Do you have the "float" option on your loader? If yes does this work?

Does the loader raise at the same speed when moving the joystick to raise or lower?

one possibility comes to mind that could cause this type of failure? You have a regernerative spool in the lift lower function of your FEL. If this true The FEL should raise faster while either trying to raise or lower. Also you should not have the float function since most directional valves have a maximum or four positions.

 

[Ben755]

I routed the FEL return line into the sump fill opening and the all FEL functions worked fine including raising the bucket. Apparently, the return fluid is being restricted somewhere in the system causing some back pressure in the return port of the FEL controller. I pulled all the lines and couplings in the return and check for blockage. The return line goes through an adjustable control valve that I blew out with compressed air. The FEL is now lowering, but it raises somewhat slower. I can live with it though. Thank all for their input and help.

 

[oldnslo]

Is the flow control in hose between the loader cylinders and the directional valve? If I would have no clue as to why that would be in there except to control the lowering speed. Look closely at this valve it may have a hydraulic schematic engraved in the side and it is possible this has a free flow function in one direction. If I would think you would only want the restriction during lowering.

glad you found the problem.

 

[Egon]

Try switching the up/down hydraulic lines to see what happens. Also take a look at the joystick k linkages and verify correct hose placement.

 

[Xfaxman]

The return line goes through an adjustable control valve that I blew out with compressed air.

Could this be the pressure relief valve? The return would come off of it.

The return line normally goes directly to the reservoir.

Need pictures.

 

[Ben755]

The link below is to a post on the forum by someone with the same tractor and loader that I have and shows pics of the hydraulic connections to/from the 3-pt cylinder housing. I took the liberty of taking a snippet capture of on pic showing these connections. I also added labels to the connections :

http://www.tractorbynet.com/forums/hydraulics/326155-adding-top-tilt.html