FEL how long 'should' bucked remain up when parked?

[DK35vince]

Well I am not familiar with your hopper bin cylinders, but I suspect they were not like our double acting cylinders on our tractors where both sides of of the cylinder (cap and rod side) are filled with oil. I suspect your cylinder is a single acting cylinder where the rod side is vented to atmosphere and the cap side is the pressure side. Your hopper returns down via gravity. Since the rod side has air not oil in it (normally) then with leaky seals, it would struggle to get it up (as you describe) and since it leaked it would fall as oil bypassed past the seals and filled the rod side with some oil as the weight of the hopper pushed it down via gravity. What I don't understand is you mentioned two cylinders for this hopper, and I don't understand how the single GOOD cylinder did not prevent the hopper from falling. I suspect your good cylinder is not good either.
Question are there two hoses going to the ends of each cylinder or just one?

The hopper is not one piece.
Each cylinder push's up one side . The bins flip in toward the center of the machine. One bin on each side flipping in. (if my explanation makes any sense.)
You may be correct, I believe they are single acting cylinders now that you mention it (power up, gravity down)

 

[ovrszd]

Yep, but I just figured he failed to mention the oil puked out on the ground.

Possibly.

 

[k0ua]

The hopper is not one piece.
Each cylinder push's up one side . The bins flip in toward the center of the machine. One bin on each side flipping in. (if my explanation makes any sense.)
You may be correct, I believe they are single acting cylinders now that you mention it (power up, gravity down)

I am having a little trouble visualizing the bins, but in any case you found your problem as a bad single acting cylinder.

 

[ovrszd]

The hopper is not one piece.
Each cylinder push's up one side . The bins flip in toward the center of the machine. One bin on each side flipping in. (if my explanation makes any sense.)
You may be correct, I believe they are single acting cylinders now that you mention it (power up, gravity down)

I've saw those. Pretty sure they are single acting. The hoppers are to throw the material dumped out of an 8ft wide truck bed toward the center to feed the machine, one on each side.

 

[DK35vince]

Yep, but I just figured he failed to mention the oil puked out on the ground.

Don't recall any leaking, or oil puking out on the ground, just didn't hold.
Barely lifted and fell immediately as some as the button was released

 

[ovrszd]

Don't recall any leaking, or oil puking out on the ground, just didn't hold.
Barely lifted and fell immediately as some as the button was released

Hmmm.... Not sure then how a replacement cylinder fixed the problem.

I'll let those more knowledgeable than I discern this one. After all, what do I know.....

 

[DK35vince]

Hmmm.... Not sure then how a replacement cylinder fixed the problem.

I'll let those more knowledgeable than I discern this one. After all, what do I know.....

This issue happened toward the end last summer. (2015)
Replaced the cylinder and its been fine ever since.
I'm guessing we put around 600 or 700 hours on the machine since then

 

[ovrszd]

This issue happened toward the end last summer. (2015)
Replaced the cylinder and its been fine ever since.
I'm guessing we put around 600 or 700 hours on the machine since then

There's an explanation in there somewhere but I don't know what it is.

 

[k0ua]

Don't recall any leaking, or oil puking out on the ground, just didn't hold.
Barely lifted and fell immediately as some as the button was released

Well, it had to. Think this through. You say it struggled to get up. That indicates leakage on the piston seals, so some oil is flowing into the rod side which is vented to atmosphere. BUT when it eventually is fully extended you say if fell after you quit pumping fluid into the cap side. If it fell, then the piston had to travel thru the oil column and IF the valve ( you mentioned a button so I am assuming it was electric over hydraulic valve) did not leak then the excess oil had to go somewhere, and it will not all fit into the rod side because the rod takes up volume as it falls into the cylinder. Oil has to puke out, and the next time you raise it more oil pukes out. You don't get out of this without puking out oil. You might not have seen it but trust me oil came out in this scenario.

I think the problem a lot of people have understanding these concepts is that they don't understand the rod has volume and when it is inserted into the cylinder it displaces oil. A number of posts back a poster alluded that there was equal volume on either side of the cylinder bore . They think that oil can leak around the piston seals and as the rod sinks lower and lower into the cylinder then the oil from the cap side can just go into the rod side due to pressure differential wanting to equalize. Now tell the truth, a lot of you out there following this thread and maybe not saying anything are thinking just that, and don't understand why a leaky piston seal can't be a solution to a leak down problem.

They just don't take into account that the rod going into cylinder takes up room in the cylinder making it impossible for the oil from the cap side to flow into the rod side, assuming the rode side external seal does not leak or the control valve or hoses and fittings don't leak. Somehow people just don't see that rod and don't take it into their thinking process I guess.

If you have a better explanation to why a few of you don't understand, let us know and we will try to work thru it.

 

[comancheflight]

So now things have calmed down the original question stands: if you put your bucket 5' in the air how long should it take, normally, before it would contact the ground? (Mainly ->) What is an acceptable bleed down rate? Do tractor manufactures have a spec for this somewhere and (this ->) when would warranty repair become an issue for it bleeding down too quickly?

My CK35 would stay up a long time..
My NX drops the rate of ~16" a day.
Not that it's a problem but it was noticeable. I didn't know what was acceptable which is the reason I asked my dealer and he immediately offered to look at it and asked me to measure and get back to him and haven't as yet. ...so I asked here. Still don't know but I did learn some ol dogs can learn new tricks...some can't.