after reading about the top link failure I have a question. MntViewRanch, you here?

   / after reading about the top link failure I have a question. MntViewRanch, you here? #1  

allen in texas

Platinum Member
Joined
Oct 26, 2007
Messages
916
Location
Levelland, TX
Tractor
Kubota Grand L 5740, loaded R1's w/640 lbs cast weight, 854 loader
Ok I read the entire thread about the toplink failure and didn't find what I was looking for so...
This is indeed a perfect response to a problem with a product. I need a tilt cylinder sometime in the future and I now know where I will buy it.
But there was a question asked and it was never answered that I can find. The question was about using a double piloted check valve on the toplink. My top link has one and I couldn't do without it. I have three remotes on my tractor and sometimes I need 4 for my implements so my top link connection is the one I sacrifice. It it weren't for the check valve, I would have to put my old manually adjustable top link back on the tractor. It's easy enough to do but I don't wanna. I just hook up, set the length of the toplink where I want it and pull the hoses. Never moves after that.
My cousin has a toplink without a check valve and he is always having to adjust it. I set mine and forget about it until I want to change it.
So Brian, why do you not use a check valve?
Certainly not for cushioning. A manual toplink has no cushioning. Of course I guess they break on occasion too. Just wondering out loud here and I may learn something in spite of myself.
 
   / after reading about the top link failure I have a question. MntViewRanch, you here? #2  
Allen,
Most check valves will hold pressures of about 600psi before releasing. In most uses that is enough to prevent movement but if you were to exceed the pressure then it can move. Not a big deal if it works for you.

The main reasons I don't want the check valves is loosing the ability to put the cylinder in float position and I find feathering much easier with less strain on the hydraulics than using flow restrictors.

It will be interesting to see Brian's response to your question.
 
   / after reading about the top link failure I have a question. MntViewRanch, you here? #3  
As mentioned, the only disadvantage I can think of is losing the float function. My similar question is why not use them on the tilt cylinder? It would be nice since there are limited uses for the side cylinder and it would free up the remotes for other attachments. I don't see much use for that cylinder to float, but maybe I am wrong.

An alternative would be to use quick couplers on the cylinder end and when detached should close it off and keep the cylinder in position. You could also use some type of shut off valve at the cylinder ports.
 
   / after reading about the top link failure I have a question. MntViewRanch, you here?
  • Thread Starter
#4  
I can't "float" my top link so I guess that is a moot point in my case. I would have thought that the check valve would hold more than 600 psi too but that's why I'm here, to learn this stuff. As far as buying a side link, from my experience, I do NOT want it to move unless I tell it to, therefore the question about the check valve.

Yes, Really interested in what Brian has to say...
 
   / after reading about the top link failure I have a question. MntViewRanch, you here? #5  
Allen, to start with, as long as you are using the std quick connects, you can just disconnect those with ANY cylinder and the cylinder is set in place. IF it moves, the seals are leaking somewhere. You do not have to have the DPOCV to have the cylinder disconnected and still be able to make use of it. You just need some QDs that don't leak. ;)

As far as the DPOCVs, I feel that they simply are not needed for use on the 3pt hitch as most of us use them. I have checked both of my tractors to see how much the rams drift. I have NEVER had any problem with either of my top links getting out of adjustment as long as the control valve is working properly. I say this because I use to have a Prince 2 spool mono block valve on my smaller tractor for the "TnT". Nothing but problems until I switched from the OEM o-rings to actual lip seals, then the valve leakage finally stopped. I now operate all of my remotes with the OEM valves supplied by the manufacturer. :cool: Do my valves leak, you bet they do, just not enough to make any difference IMO. My side links leak at a rate of just under 3/16" of an inch per hour. That is with a 1000lb implement hanging on the hitch while I was in eating lunch. I would say that when the implement is on the ground that some of the weight is then taken off of the hydraulic although you do have the stress of the implement being pulled on as the implement is being used. We get the hydraulic links so that we can make adjustments. How often depends on what a person is doing AND how good that person is at what they were doing. I would say that most of my sales go to people that are doing grading. When you grade, you constantly adjust the setting. I personally very seldom go for even 10 minutes between adjustments. At that rate, my ram might have drifted a whole 30 thousandths of an inch. I think that for most of us, that is what is considered "good enough".

In my opinion, the check valves are just a band aid for a bad control valve that should either be rebuilt or replaced. If they were actually needed, wouldn't the tractor manufacturers that provide "TnT" units have them? :confused3: Neither John Deere or Kubota offer them on any of their tractors that we are all familiar with. None of the industrial guys have them, not Case, JD, Cat, none of them that I know of.

As far as the use of the float function, I will list a few and I am sure that there are more. The floating option is removed anytime that there is a DPOCV involved and THIS is why I do not use any of them.

Top link, there are people that mow in some rough terrain. They want their mower to follow the ground, not the tractor. Yes there are articulated center mounts for mowers. Not everyone has them and I had a customer that did have that option and his mower still did not move enough for his uses. He needed to have his mower be able to move even more and a floating top link allowed for that movement. Some people use chains, besides not being safe, a chain only allows for the implement to come up toward the tractor, not away from it like a floating hydraulic top link does.

Side link, I personally use float at the intersections of the 2+ miles of road that I maintain. The camber of the road changes as you move through the intersection. At this time I kick the side link into float and the implement then follows the road, not the tractor. It's not for a long ways, but it sure does finish off nicer than if I didn't have it. :thumbsup:

Plowing snow, this allows for the blade to follow the ground and keep a constant cut on the ground. Same goes for a snow blower.

There is a TBNer that has posted how great it was raking his rough fields and allowing the rake to follow the ground instead of having the constant up and down motion that he would have otherwise had.

Just a few, but now you know why it didn't get answered. One of these days I will get the explanations up on the Fit Rite website and I won't have to write this out any more. ;)
 
   / after reading about the top link failure I have a question. MntViewRanch, you here?
  • Thread Starter
#6  
Well cool!! :) Now I know. I have a kubota (175 hours on this one) and my cousin has a kubota (50 hours). Since I've never used my top link without a check valve, I can't say if my tractor valves leak or not but 'something' is leaking past on my cousin's tractor. As far as the connectors leaking, mine will leak. I didn't know there was one that wouldn't . The uses you mentioned for the side link floating is a good point. My problem is this...how do you 'float' the cylinder? My controls don't do that.
 
   / after reading about the top link failure I have a question. MntViewRanch, you here? #7  
I would like to be clear that there is NOTHING wrong with having the check valves. The main reason that I am not an advocate for them is because of the loss of all the options of being able to use the float function and there are many instances where being able to use the float function is better than not using it.

Then the problem becomes that the customer needs to know that they should either have gotten their remotes with the float function or that they need to order them that way if that is the process that they are in at the time. From what I have either seen or read, the customer needs to know this stuff, because most of the dealers sure don't. I explain this stuff all the time, and apparently some dealers are paying attention, because even they have been asking questions lately. :cool:

Allen, for your L5740, I don't know if it is possible to get the Kubota float function only from parts and get it that way, or if you would have to get a whole new valve. With most of the aftermarket valves, the float function is an easy install and relatively inexpensive to add on. I just don't know how Kubota does theirs. :eek: If your cousin has more than one set of remotes, have him switch them and see if the top link still leaks, It might, it might not. I have customers where that is all it took to take care of the problem. ;)
 
   / after reading about the top link failure I have a question. MntViewRanch, you here?
  • Thread Starter
#8  
Cousin only has one remote. I guess he has to live with what he has. I told him he needed at least 2 but did he listen to me. Noooope. Oh well. Thanks for all the info. When I get finished spending money on all of my other toys...I mean implements, I'm going to get a side link. I could really use one with my box blade.
 
   / after reading about the top link failure I have a question. MntViewRanch, you here? #9  
Brian, while you are here kindly answering questions I have one. I notice that you now provide flow restricters with your kits. These did not come with my older kit but I don't seem to have any trouble adjusting either the top or side links with the precision I need. Why do you now include these ? And would they make my life even easier if I added them? I have factory Kubota remote valves on my L3010. Thanks for taking the time to help.

gg
 
   / after reading about the top link failure I have a question. MntViewRanch, you here? #10  
Allen,
Most check valves will hold pressures of about 600psi before releasing. In most uses that is enough to prevent movement but if you were to exceed the pressure then it can move. Not a big deal if it works for you.

The main reasons I don't want the check valves is loosing the ability to put the cylinder in float position and I find feathering much easier with less strain on the hydraulics than using flow restrictors.

It will be interesting to see Brian's response to your question.

Steve, I think you are confusing the 600psi spec on the DPOCV's unless I am misreading your post. The 600 psi number is the "cracking" pressure, in other words it needs to see at least that amount on the input side before it will allow fluid to flow to the out side or allow the cylinder to move. It can certainly hold more than 600 psi.
 
 
 
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