JD 200CX issue

rtm038 · May 21, 2009

Hello all,
Recently the 200CX loader on my JD2520 has been acting up. It lifts, lowers, dumps and scoops fine, but when you tilt the bucket forward and try to backdrag the ground with the cutting edge, the bucket rotates upwards (like after you drive into a material pile and big to "scoop" it up). Basically, the bucket will not hold the position. Could there be a problem with the loader valve? Is there a relief valve in the loader valve for the scoop part of the circuit that might be sticking in the "open" position? I can't imagine its air in the system, seeing how this has been going on for a few weeks now and the machine has been used on an almost daily basis, so I would assume any trapped air would have been worked out by now.

Thanks
Ryan

kennyd · May 21, 2009

Two thoughts Ryan:

1. You should NOT backdrag with the cutting 90* to the ground, you risk bending your dump/curl cylinders if the lip catches on something. It's best to backdrag with the heel of the bucket-and filling the bucket with material(to make it heavier) really help in some situations.

2. To solve the problem, you will need to hold the joystick open for a few seconds after the bucket stops moving, it IS air is the cylinders from cavitation, and holding the joystick will expel the air. Your FEL valve has a feature called "regen" or "regenerative" to help alleviate this condition. You can read more about that HERE and/of search the term "regen".

rtm038 · May 21, 2009

kennyd said:
Two thoughts Ryan:

1. You should NOT backdrag with the cutting 90* to the ground, you risk bending your dump/curl cylinders if the lip catches on something. It's best to backdrag with the heel of the bucket-and filling the bucket with material(to make it heavier) really help in some situations.

2. To solve the problem, you will need to hold the joystick open for a few seconds after the bucket stops moving, it IS air is the cylinders from cavitation, and holding the joystick will expel the air. Your FEL valve has a feature called "regen" or "regenerative" to help alleviate this condition. You can read more about that HERE and/of search the term "regen".

Thanks for the response. I don't backdrag with the cutting edge 90 degrees to the ground, more like 45 to 30 degrees. Either way, I'll try holding the joystick open for a few seconds like you described and see if that clears up the issue.

Thanks again
Ryan

carpenter383 · May 21, 2009

I was about to post a very similar question. My new kioti does almost the same thing. the curl cylinders push in a few inches before they "take the load" when back dragging. If I dump the bucket all the way it will be fine until I dig into a pile of dirt, then it does it again. I haven't tried to hold pressure on the bucket when dumped, I'll have to try that thanks Kennyd...... BTW I don't roll the bucket back much when back dragging either.

carpenter383 · May 21, 2009

So does the joystick have to be held in fast dump to get the "regen" going and the air out of the system? Or does it just need to open the relief valve to "regen". I ask because my lift cylinders do the same thing but not as bad.

kennyd · May 22, 2009

carpenter383 said:
So does the joystick have to be held in fast dump to get the "regen" going and the air out of the system? Or does it just need to open the relief valve to "regen". I ask because my lift cylinders do the same thing but not as bad.

Getting the system in "relief" for a few seconds is the solution.

carpenter383 · May 22, 2009

Ok thanks!

Gizmo2 · May 22, 2009

I always cycle the hydraulic attachments to their limits a few times prior to actually using them.
You'll also see this when using an attachment for a period of time without hitting the hydraulic limits of the attachment especially on a loader where it takes next to no hydraulic pressure to dump a bucket load and it is the weight of the material that is actually dumping the bucket not the hydraulic pressure and then when you need the dump cylinder pressure it's not there, the oil has been displaced.

carpenter383 · May 22, 2009

Gizmo2 said:
I always cycle the hydraulic attachments to their limits a few times prior to actually using them.
You'll also see this when using an attachment for a period of time without hitting the hydraulic limits of the attachment especially on a loader where it takes next to no hydraulic pressure to dump a bucket load and it is the weight of the material that is actually dumping the bucket not the hydraulic pressure and then when you need the dump cylinder pressure it's not there, the oil has been displaced.

So this something that needs done on a regular basis and is normal? I held pressure on the cylinders to "regan" and bleed the air. It worked, but wasn't permanet because the bucket got "floppy" again.

Gizmo2 · May 22, 2009

I would say normal, although I cannot tell exactly what you are doing when the bucket gets floppy.
I don't think it really has to do with air in the lines as much as lack of pressure on the lines. It is the same thing as parking you tractor with a backhoe on it and the out riggers in the up position. The out riggers will eventually fall to the ground as the pressure bleeds off. Think of the pistons on your loader as one piston acting as two and when moving dirt the dump side of the piston never really gets utilized thus the pressure bleeds off and does so faster than you would think. I was once told that the bigger, real loaders do not do this near as much because the valves in the hydraulics are much better than these home use units and of course more money. With all that said, I could be wrong!