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

[LD1]

I got it now!
There was no way in heck I could be wrong! But, I was. The piston could move inside the cylinder with a leaking seal as I believed, if it was not pulling in the rod to which it is attached, from the outside of the cylinder. The addition of the outside rod into the inside of the cylinder is not possible.
My brain block is removed.

Glad we could help remove that brain block.

For every person that learns/understands, is one less person spreading the false information about needing cylinders rebuilt.

 

[ray66v]

I got it now!
There was no way in heck I could be wrong! But, I was. The piston could move inside the cylinder with a leaking seal as I believed, if it was not pulling in the rod to which it is attached, from the outside of the cylinder. The addition of the outside rod into the inside of the cylinder is not possible.
My brain block is removed.

+1

It's a little confusing, because, if you start out with a sealed, retracted double acting cylinder, full of oil, you can in fact pull the ram out, and push it back in all day, when it has an internal leak. That's how we always tested them.

I see now, if you start out with it extended, it's a whole different ballgame.

 

[LD1]

+1

It's a little confusing, because, if you start out with a sealed, retracted double acting cylinder, full of oil, you can in fact pull the ram out, and push it back in all day, when it has an internal leak. That's how we always tested them.

I see now, if you start out with it extended, it's a whole different ballgame.

Starting out with it extended, or partially extended is the exact same set of circumstances that happen when a loader drifts.

Nobody is talking about starting with the loader on the ground and lifting it by means other than its own hydraulics, and then watching it drift. Which is what you imply.

 

[Richard]

When I ripped out the floor in my upstairs bedroom, I de-nailed it in the room and tossed the trash out the window into my loader bucket (industrial machine)

I had the bucket raised as high as it would go to make the toss a bit easier (2nd floor up)

We have no kids so I didn't have to worry about anyone playing around the machine and, live in country so no neighborhood kids!

Anyway, I left it up like that for several days, maybe two weekends.

After a number of days, the bucket only lowered by a couple feet from full height. It never did hit the ground until I brought it down.

Other than that, I'm in the keep it on the ground with pressure relieved in the system camp.

I see some (people parking them or maybe dealers) with the bucket raised in air and just shudder at what could happen.

 

[DK35vince]

Richard, no one is contending that the FEL arms do not drop over time. They all do to one extent or another unless some sort of valve like a needle valve is put in line to eliminate the flow of the oil back to the control valve. All we are contending is that the leak down and drop of the FEL arms are not due to leaky piston seals because for that to occur then the rods would have to be pushed into the cylinders, and for that to happen the oil inside the cylinders have to go somewhere.

The place the oil goes is back down the hoses and thru the control valve back into the tank. Or in the event of leaky rod seals that let the oil fall out onto the ground or a leaky hose or leaky connections. In any case the oil must go somewhere, and it CANNOT EVER NEVER NEVER NEVER flow from the cap side past the piston seal and into the space on rod side of the cylinder. That is a physical impossibility no matter how badly the piston seal fits into the bore or even if the piston is present at all.

That is all we are saying..

If all this is true maybe you can explain this to me.
We had an asphalt paver at work, there are hydraulic cylinders mounted on the side of the machine that push up the hopper bin to dump material onto the flight chains in the front of the machine. (one cylinder for each side of the machine for the bin)
These cylinders extend out to push the bin up.
The bin would barely go up on one side, as soon you released the button that hopper bin would fall compressing the cylinder all the way closed.
We replaced the cylinder and its been fine ever since.
It wasn't a valve issue, it was the cylinder
According to what you are saying here that's not possible, but it did.

 

[ray66v]

Starting out with it extended, or partially extended is the exact same set of circumstances that happen when a loader drifts.

Nobody is talking about starting with the loader on the ground and lifting it by means other than its own hydraulics, and then watching it drift. Which is what you imply.

I never said, or implied, that, or anything of the sort.

I stated the reason why I believed it was possible for them to drift down.

 

[ovrszd]

Popcorn.

This discussion always goes this way. I think it's because each posters position is different. And each poster assumes everyone else is standing in the same position they are. That was my point in disputing the "confined cylinders can't drift" comment. Then when there is contention everybody starts back peddling. That was the reason for my post with picture. Back peddle, back peddle.

I get it that a completely isolated cylinder full of oil cannot be moved.

There have only been half a dozen posts that truly claimed that. Most others add contentions that muddy the waters. Then when contested, there's dispute. It's always the same.

 

[k0ua]

If all this is true maybe you can explain this to me.
We had an asphalt paver at work, there are hydraulic cylinders mounted on the side of the machine that push up the hopper bin to dump material onto the flight chains in the front of the machine. (one cylinder for each side of the machine for the bin)
These cylinders extend out to push the bin up.
The bin would barely go up on one side, as soon you released the button that hopper bin would fall compressing the cylinder all the way closed.
We replaced the cylinder and its been fine ever since.
It wasn't a valve issue, it was the cylinder
According to what you are saying here that's not possible, but it did.

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?

 

[ovrszd]

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?

I was typing while you were James.

In regards to a single acting cylinder. If the seals within that cylinder are leaking it's very easy to detect. When the cylinder is fully extended it will puke oil out the atmosphere vent.

 

[k0ua]

I was typing while you were James.

In regards to a single acting cylinder. If the seals within that cylinder are leaking it's very easy to detect. When the cylinder is fully extended it will puke oil out the atmosphere vent.

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