My new to me 2016 L47 with 400hrs, the FEL Bucket Tilt Drifts down over 2hrs, I do not believe this to be acceptable/normal, any ideas how to correct it. Thanks.
FEL Bucket tilt Drifts down over 2hrs
- Thread starter Vlach7
- Start date
Cylinders may need repacked. Any leaks?
Switch the lines at the control block. If nothing changes, it’s the cylinders. If boom leaks, its the valve.
Switch the lines at the control block. If nothing changes, it’s the cylinders. If boom leaks, its the valve.
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RCW
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Tips down how? Do you have the loader lifted in the air with the tractor off, and the bucket dips down?
No leaks. I believe either, running and not, don't usually sit there that long with it running. Not running on the Tractor, FEL lifted, bucket tilt level, bucket tilt very slowly tilts bucket down. Not good when you are working elevated in the bucket with supplies, painting, tree trimming, ect...
Unsupported hydraulics should be on the ground when you leave the machine - for safety reasons.
Even new machines have some drift. 2 hours isn't all that bad.
Standing in an elevated bucket is the definition of industrial accident.
Even new machines have some drift. 2 hours isn't all that bad.
Standing in an elevated bucket is the definition of industrial accident.
A couple of points:
* all spool valves leak to some degree, depending on the clearance between spool and body, the amount of overlap at the lands, the viscosity of the oil/temp of the oil, etc.
* new piston seals on a new cylinder barrel should not leak, but worn seals on a scored barrel will leak.
* irrespective of the conditions of the piston seals, if the cylinder ports are sealed/closed off, a double-acting cylinder cannot be retracted, say at about mid-stroke, because a larger volume of oil in the piston end cannot fit into a smaller volume (space) in the rod end. (same as a simple bottle car jack)
* however, with the same cylinder and setup above, the cylinder can be extended if the piston seals are leaking, fast or slow depending on how worn the seals are.
* remember, if, say 3000psi is applied to the piston end, and oil in the rod end cannot get out, for what ever reason, intensification will occur and induce a very high pressure in the rod end, depending on the ratio of the piston and rod diameters, but could be up to, say 6000psi. This is easy enough to blow a rod seal, or bulge the barrel.
GreensvilleJay
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re:
Not good when you are working elevated in the bucket with supplies, painting, tree trimming, ect
This is a really ,really BAD practice, unless your life insurance is paid up.
Young framer here(early 30s), fell off a 7' roof(think garden shed)...will never work again in the trade..destroyed his right foot/ankle bones. 'freak' accident..he's got 40+ years of pain and sufferin ahead.
Now have we done what you said, probably, but why take the chance. If you need a 20' ladder, you can have any of 3 I have,for free.
Not good when you are working elevated in the bucket with supplies, painting, tree trimming, ect
This is a really ,really BAD practice, unless your life insurance is paid up.
Young framer here(early 30s), fell off a 7' roof(think garden shed)...will never work again in the trade..destroyed his right foot/ankle bones. 'freak' accident..he's got 40+ years of pain and sufferin ahead.
Now have we done what you said, probably, but why take the chance. If you need a 20' ladder, you can have any of 3 I have,for free.
TheOldHokie
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Clip and paste these basic principles at the top of your hydraulic troubleshooting pert chart.
Dan
Standing in an elevated bucket is testing Darwin's Theory of Selectivity. Darwin was right, and he wasn't necessarily talking about the strongest creature being dominant. He was talking about the smartest outliving the strongest with intelligence.
Like @GreensvilleJay said, if you need a ladder, I'll loan you mine free of charge. A front-end loader bucket is NOT a man-lift and never should be used as one. Some will argue that, but a working platform for occupancy is why MAN-LIFTS were designed. Your favorite equipment rental dealer will have what you need and probably even drop off and pick up if that's what you want. If you want a man-lift, get a man-lift.
You really need to care more about fall protection. It doesn't take a high fall to seriously injure you. My dad fell off a 6' high scaffold that wasn't properly inspected and secured when I was 12 years old. This was before OSHA realized that the NUMBER ONE cause of industrial/commercial fatalities was falling from height, and a very large percentage of those falls was from risk taking and improper safety measures. He spent the next 26 years of his life in a VA hospital with an injury that was approximately equivalent to a frontal lobotomy. He didn't break a single bone in the fall other than a hair-line skull fracture. He didn't know where he was, why he was there, or who I was (nor any of my siblings) for nearly 15 of those 26 years. His confinement was little more comfortable than a prison because he was kept on locked wards because of his flight risk. I can't count the times I had to go pick him up at bus stations and haul him back to the hospital. Every time they thought they could ease up on him, he was out the gate. He had no clue where he was going, his only destination being AWAY from that hospital. We all had our own busy lives and could not give him the care and monitoring he needed. The complications and side effects of a brain injury ended his life before age 50. I've outlived him by 14 years already, because I learned from it. Your fall and injury won't just affect you. Trust me, EHS got no argument from me about harnesses and fall protection. Living through a head injury like that scares me more than dying from it. I've SEEN what it does.
I've seen a lot of folks here use modified IBC totes and fork adapters for that purpose and have a second person running the tractor. Even that scares the bejeebers out of me. Someone on the seat doesn't make it safer. In fact, considering the hydraulics I'm familiar with on my LX, I think it would be similar to the squirrel catapult I've watched over and over on Youtube, only I'd be the squirrel. Ain't no way I'm going up in a makeshift man-lift, nor am I going to lift anyone else up with it. My life is worth a lot more than the cost to rent a machine designed to raise me up safely. At least that's what the missus tells me.
Like @GreensvilleJay said, if you need a ladder, I'll loan you mine free of charge. A front-end loader bucket is NOT a man-lift and never should be used as one. Some will argue that, but a working platform for occupancy is why MAN-LIFTS were designed. Your favorite equipment rental dealer will have what you need and probably even drop off and pick up if that's what you want. If you want a man-lift, get a man-lift.
You really need to care more about fall protection. It doesn't take a high fall to seriously injure you. My dad fell off a 6' high scaffold that wasn't properly inspected and secured when I was 12 years old. This was before OSHA realized that the NUMBER ONE cause of industrial/commercial fatalities was falling from height, and a very large percentage of those falls was from risk taking and improper safety measures. He spent the next 26 years of his life in a VA hospital with an injury that was approximately equivalent to a frontal lobotomy. He didn't break a single bone in the fall other than a hair-line skull fracture. He didn't know where he was, why he was there, or who I was (nor any of my siblings) for nearly 15 of those 26 years. His confinement was little more comfortable than a prison because he was kept on locked wards because of his flight risk. I can't count the times I had to go pick him up at bus stations and haul him back to the hospital. Every time they thought they could ease up on him, he was out the gate. He had no clue where he was going, his only destination being AWAY from that hospital. We all had our own busy lives and could not give him the care and monitoring he needed. The complications and side effects of a brain injury ended his life before age 50. I've outlived him by 14 years already, because I learned from it. Your fall and injury won't just affect you. Trust me, EHS got no argument from me about harnesses and fall protection. Living through a head injury like that scares me more than dying from it. I've SEEN what it does.
I've seen a lot of folks here use modified IBC totes and fork adapters for that purpose and have a second person running the tractor. Even that scares the bejeebers out of me. Someone on the seat doesn't make it safer. In fact, considering the hydraulics I'm familiar with on my LX, I think it would be similar to the squirrel catapult I've watched over and over on Youtube, only I'd be the squirrel. Ain't no way I'm going up in a makeshift man-lift, nor am I going to lift anyone else up with it. My life is worth a lot more than the cost to rent a machine designed to raise me up safely. At least that's what the missus tells me.
In order for the cylinder to extend, oil needs to move out of the rod end into the other end but it is already full. How is that going to happen? The total quantity of oil needs to increase in order to extend, correct?
TheOldHokie
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No - the smaller flow from the rod end only partially fills the added volume and it pulls a vacuum. If you release the load pulling on the rod it will retract under atmospheric pressure.
Dan
Or maybe there is a leak letting air get into the system when a vacuum is pulled? Perhaps just small enough to let air in but impede the flow of hydraulic oil in the other direction?
Since the cylinders are in parallel, one leak would affect both equally. When the cylinders were activated in normal operation, the air would be purged from the system, only to be reintroduced when the loader was at rest with the bucket hanging in the air.
Just brainstorming...
TheOldHokie
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Air leak is possible but it wont get pulled in unless the spool is leaking or piston bypassing and allowing the rod to drift out.Or maybe there is a leak letting air get into the system when a vacuum is pulled? Perhaps just small enough to let air in but impede the flow of hydraulic oil in the other direction?
Since the cylinders are in parallel, one leak would affect both equally. When the cylinders were activated in normal operation, the air would be purged from the system, only to be reintroduced when the loader was at rest with the bucket hanging in the air.
Just brainstorming...
Dan
What if the leak is at a connection between the control valve and the cylinder input?
Or even, although only theoretically possible, and unlikely I would guess, if there was a hole with an internal flap, that would let air in through a hose wall, but due to the orientation of the flap, would block leakage outward? I know this is a stretch...just posing the question for the sake of discussion...
I just looked back and the OP says it takes two hours for the bucket to droop, and I ASSUME he means at least half stroke of the cylinders, and maybe more.
Is it likely enough vacuum could be pulled to lock a cylinder? I suppose not, as once a vacuum is pulled, it can only cause so much force on the rod end of the piston. So at some point the piston would reach a limit on pull back due to the formation of a vacuum. And then continue to move.
It seems to this simple mind that a vacuum could only cause the rod end of the cylinder to push the piston with a force equal to air pressure at the altitude, times the area of the cylinder bore. Do not think that is very much force.
So for the bucket to drop, the fluid in the rod end must be going somewhere. It could be going back to the other side of the cylinder through an external path, if there is no internal leakage, or it must be going back somewhere through the control valve. OR maybe there is a some other way it could be going somewhere, but that would have to be related to the other cylinder somehow I would bet.
At this moment in time, I kind of want to conclude that the issue is likely leakage through the control valve, through the path that is connected to the rod end of the cylinder.
Is it likely enough vacuum could be pulled to lock a cylinder? I suppose not, as once a vacuum is pulled, it can only cause so much force on the rod end of the piston. So at some point the piston would reach a limit on pull back due to the formation of a vacuum. And then continue to move.
It seems to this simple mind that a vacuum could only cause the rod end of the cylinder to push the piston with a force equal to air pressure at the altitude, times the area of the cylinder bore. Do not think that is very much force.
So for the bucket to drop, the fluid in the rod end must be going somewhere. It could be going back to the other side of the cylinder through an external path, if there is no internal leakage, or it must be going back somewhere through the control valve. OR maybe there is a some other way it could be going somewhere, but that would have to be related to the other cylinder somehow I would bet.
At this moment in time, I kind of want to conclude that the issue is likely leakage through the control valve, through the path that is connected to the rod end of the cylinder.
TheOldHokie
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It does not matter how far you pull the rod out the maximum vacuum it can produce is one atmosphere.
The rod end fluid either goes back into the base end of the cylinder or it leaks externally. That could be to a parallel cylinder which would also have to drift, the control valve, or onto the ground. With a 2 hour leak down my first suspicion would be the control valve. Do the arithmetic assuming a 10cc/minute leakage and and let me know what you get.
Dan
No argument using a ladder is often the wise thing to do.
BUT I will mention something that happened to me with a ladder, so nothing is fool proof. OR maybe "Henro proof" would be a better term?
There was a branch on a large willow tree that I wanted to remove. It was running horizontal for a distance, and maybe less than 8" in diameter at the tree trunk end.
I put my ladder up on the side of the tree, somewhat to the back, but out enough that I could cut the branch. Somehow, the branch when it fell, sprung back and kicked out the bottom of the ladder.
Fortunately, I was smart enough to tie off the top of the ladder, and I stayed on it as the bottom swung in the air. Had I not done that...things would have turned sour for sure.
Now it is also argued not to use a chain saw off of a ladder I think...
Anyway, there is no sure cure to possible accidents.
I have used my loader as a work platform occasionally, and will probably do it again.
I kind of comes down to "what are the chances?"
If one wants to maximize his chances he best not do anything.
Kind of the simplistic way I look at things I suppose...
No need for me to do any math. I think we are saying the same thing.
So the next step, is what should the OP do to isolate the issue and find the cause.
Perhaps the first easy step would be to pull the loader bucket quick disconnects off the control valve and see what happens as far as bucket drift goes?
He could do this with the bucket on the ground, then lift the bucket off the ground and watch what happens.
Just a thought...
TheOldHokie
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Raise the bucket to chest height, curl, and disconnect the bucket couplers. If it leaks down and there is no oil on the ground its in the cylinders. You could probably speed the test up by hanging a couple hundred pounds on the cutting edge. When the cylinder seals on my B1630 went south a loaded bucket would leak down in under a minute.
Dan