am I getting the runaround?

[daugen]

There's a big difference in an inch an hour versus 3" in half an hour. An inch an hour while operating is quite reasonable in my opinion, 3" in half an hour would be totally unacceptable. So I'm not sure which it is now.

you're right, but it's likely the three inches on the heavy mower; the rake is much lighter and goes down more slowly. In fact the pic is an overnight result.
Personally I think even an inch an hour is too much. It's one thing on a box blade, it's another on a mower that gets out of tilt and mows unevenly.

 

[MtnViewRanch]

First thing to do to trouble shoot is to raise the side link up all the way. With the implement on the ground, unplug the quick connects from the female connection points. Raise the 3pt hitch and come back and look in 1 hour. Be sure that the tractor is in a location where no person or animal can be hurt because of the implement being left in the air and possibly falling. That will give you an actual rate of fall per hour.

Do this and we will go from there.

 

[JeffTerry]

My tnt has had a drooping right cylinder since I got it. Back several times to the dealer, under warranty, and
no solution, told they all do to some extent.

I don't get it. With a heavy mower on the back, the right side drops over three inches within a half hour.
How can that be considered within normal operating parameters? I can see overnight, but shouldn't you be able to set your
hydraulics at a certain point and have them stay there, perhaps for quite a while?

here's what the dealer wrote:

I called again the manufacturer of the lift link cylinder and confirmed
that there isn't a check valve of any type on this cylinder. The leakage you are experiencing
on that cylinder happens in the tractor valve. Kubota told me earlier that all remote valves
leak down over time, some a little faster that others.

There is a type of check/safety valve on the top link cylinder to allow breakaway under
too much force.

Ok, so how much time is "over time"? How much drop would you all put up with over what length
of time and consider it reasonable? This seems dysfunctional here, an attachment piston that will not hold its position.
Suggestions? many thanks

Ok, I here what your saying, nothing new should leak down like you are saying, I would be upset too. Call another Kubota dealer and make an inquiry about it and the safety standards of such an act. Just saying safety is paramount no matter how you look at it.
I deal with tractors everyday, I would not tolerate this leak down. its a pain, its unsafe, it should be taken care of. If this machine is new, or less than 200 hours tell them to fix it under warranty or call better business bureau

 

[MtnViewRanch]

There is nothing wrong with the DPOCVs. But by having them IF you have the float function available to you, you have just eliminated all working possibilities that you had by using the float function. If you are a person that does not understand the many uses of having the float function, then you are just as well off or even better off having the DPOCVs. But there are benefits to having the float function available with the top and tilt systems.

Some of you go on and on about cylinders without check valves and how bad they are. Most of the time it is not the cylinders that leak, but the control valves. Have any of you ever thought about what the actual problems are when the cylinders drift down? If it was the cylinders, wouldn't every manufacturer be putting the check valves on their units? Actually if the piston rings were leaking, the DPOCV would do nothing to prevent drifting. It would all be internal and the check valve is outside. And yet not one tractor company has them. Not Kubota, not John Deere, no industrial tractors have them that I know of. Not Cat, Case, Deere, New Holland, none of them.

So if the cylinders are the problem, why isn't there someone other than the one single company that uses the check valves for the side links?

It has been my experience that the drifting almost always is from the control valves. These normally can be serviced and either the problem is taken care of or at least improved.

 

[daugen]

It has been my experience that the drifting almost always is from the control valves. These normally can be serviced and either the problem is taken care of or at least improved.

good to know, thanks. So swapping the lines around should confirm this?

 

[MtnViewRanch]

It has been my experience that the drifting almost always is from the control valves. These normally can be serviced and either the problem is taken care of or at least improved.

good to know, thanks. So swapping the lines around should confirm this?

To start with, unplug the lines as I described. This will confirm if the cylinder is leaking or if it is the control valve. If the cylinder does not leak down or very little, THEN plug into a different set of outlets to try out a different valve.

Be sure to do ONLY ONE PROCEEDURE at a time. Other wise you never really know the results of a test. You need to confirm where the problem is to be able to take care of what the problem is.

 

[DK35vince]

There is nothing wrong with the DPOCVs. But by having them IF you have the float function available to you, you have just eliminated all working possibilities that you had by using the float function. If you are a person that does not understand the many uses of having the float function, then you are just as well off or even better off having the DPOCVs. But there are benefits to having the float function available with the top and tilt systems.

Some of you go on and on about cylinders without check valves and how bad they are. Most of the time it is not the cylinders that leak, but the control valves. Have any of you ever thought about what the actual problems are when the cylinders drift down? If it was the cylinders, wouldn't every manufacturer be putting the check valves on their units? Actually if the piston rings were leaking, the DPOCV would do nothing to prevent drifting. It would all be internal and the check valve is outside. And yet not one tractor company has them. Not Kubota, not John Deere, no industrial tractors have them that I know of. Not Cat, Case, Deere, New Holland, none of them.

So if the cylinders are the problem, why isn't there someone other than the one single company that uses the check valves for the side links?

It has been my experience that the drifting almost always is from the control valves. These normally can be serviced and either the problem is taken care of or at least improved.

I have never needed float function with my top/tilt. So its been a non issue.

I really don't know what caused my top and tilt cylinders to leak down constantly. If it was the cylinders or the control valve causing the problem. I really don't care what the reason was.
Once I put on the cylinders with check valves the leak down problem was gone. They have been on there for years and they never leak down.

 

[MtnViewRanch]

I have never needed float function with my top/tilt. So its been a non issue.

I really don't know what caused my cylinders to leak down constantly. If it was the cylinders or the control valve causing the problem. I really don't care what the reason was.
Once I put on the cylinders with check valves the leak down problem was gone.

I don't disagree. If you are a person that has no need to have and use the float function, then the Cylinders with the DPOCVs took care of your problem and you are happy. :thumbsup:That is what works for you and your conditions. But everyone does not have your conditions.

I personally would have many finish grading problems without the use of the float function as would many of my customers.

 

[MHarryE]

A spool valve is just that - a spool moving in the bore of a valve. If you can move the spool that means there is clearance between the spool and the bore hence the leakage path. Tighten the clearance up and you will get zero leakage but you also will not be able to move the spool. Tighter clearances reduce leakage as does higher viscosity fluid. I have in the past needed a zero leakage valve to satisfy customer complaints about drift in a complex steering system (front steer, rear steer, coordinated steer and offset steer modes) and so had a valve designed that had multiple pilot operated checks along with the spools but it was very expensive. Now I farm with many pieces of equipment from many brands and they all leak to some extent. The old ones leak more than the newer ones - logical because parts wear. My top and tilt drift so depending on the load I need to reset position at intervals but the utility is such that I haven't installed POC's on them. The cylinders are good - disconnect the hoses and they maintain position but then I have lost usefulness. And I disagree with one statement in this chain that Cat does not use POC's. the response may have been intended to mean in specific applications but I had a number of circuits on machines for which I was responsible that had POC's. they not only eliminate drift (if machined correctly) but they also prevent sudden movement - well, any movement, if a line breaks. Look on the web for the Husco 9200 Monoblock, one of the most commonly used valves on tractors by companies such as John Deere. Note that it states consistently low work port leakage. They do not claim zero leakage. But if you go through their options they can supply you a zero leak valve by incorporating checks.

 

[MtnViewRanch]

My statement about the industrial machines not having the check valves is that they do not have them on their 3pt hitch hydraulics, not that they do not use them at all. To the best of my knowledge, no tractor manufacturers use the check valves on their top and tilt sets that come with the tractors.