580sl. Does this Hyd. Cyl. piston need to be replaced?

[iko]

Things definitely felt sketchy the last couple of attempts. I found a $200 air impact online that claims about 4000 ft.lbs and decided to order it. Much safer and it's cheaper than my 12k deductible health insurance.

Sounds to me like a really good investment for now and future.

 

[Delmer]

Yes, you should be able to feel that sort of damage, if you can reach it, and it's clean. Use your fingernail also, if the piston is still on the rod, you can narrow it down to two locations depending on which way the rod was sitting in the cylinder. 3 o'clock and 9 o'clock for example. It's possible it was rebuilt like that in the past?

The impact is going to need a short big hose straight to the compressor tank, no valves or quick couplers, to make the most of the power.

 

[iko]

For what it's worth you if you don't have a bore scope you may pass on getting one for this task. The dent on my 4" diameter barrel was about 30" from the open end and indented maybe 1/8". I could see the dent inside with the naked eye if light was falling a certain way. I have a fairly new borescope with led lights on the camera head, but for the life of me it couldn't show almost anything because of the light reflections inside. I knew there must be scratches on the dent from the piston being pulled through forcefully and could barely see them with the naked eye but not with the borescope. Just my 2c

 

[Doug580l]

Well, you guys called it. I found the dent in the barrel. It's at the bottom. If you look at the piston you can see how far up from the bottom it is because the upper ridge on the piston is only slightly damaged whereas the bottom one is a lot worse. This also explains the strange looking damage to the seal.

Probably a dumb question, but is there any way to stop the cylinder from closing completely? If it stopped about 1-3/4" up form the bottom, the seals would be above it. As a general rule, I try not to completely close the cylinder but it happens. Could something be welded to the bottom of the piston?

I would like to acknowledge and thank everyone for the help, it is very much appreciated.

 

[Doug580l]

Oops, forgot the picture.

 

[iko]

If it's at the very end I suppose the easiest would be to turn a piece of steel on the lathe and drop it in. As long as it doesn't interfere with the hydraulic fluid inlet at that end. Then you only lose a tiny bit of the range.

The way I handled mine was to get a pipe expander set and use the largest adapters for the 4" barrel. The problem with those pipe expanders is that the adapters are of aluminum, so I cut a steel outer sleeve and used it as a wrap around. Then used the torch to heat up the dent and used many socket extensions to get the pipe expander to the dent. The barrel at the dent did not get fixed perfectly, but good enough to no longer damage the seals. I also used a whole bunch of fine sandpaper to fix the scratches made by the piston on the dent. When I put the piston back in I did my best to align the groove on the piston with the dent. I'm not saying you should do this, as I had little hope it would work, plus it was a lot of labour. You have the advantage of having the dent very near one end, so your idea of reducing the rod travel range is, me thinks, better.

 

[DMiller]

After seeing the above photo, I am suspecting a Assembly damage issue, someone resealed and snagged the edge of the seal groove on the barrel edge. Displaced metal deep into groove uplifted that spot on the piston, not gouged down into it.

 

[Doug580l]

If it's at the very end I suppose the easiest would be to turn a piece of steel on the lathe and drop it in. As long as it doesn't interfere with the hydraulic fluid inlet at that end. Then you only lose a tiny bit of the range.

The way I handled mine was to get a pipe expander set and use the largest adapters for the 4" barrel. The problem with those pipe expanders is that the adapters are of aluminum, so I cut a steel outer sleeve and used it as a wrap around. Then used the torch to heat up the dent and used many socket extensions to get the pipe expander to the dent. The barrel at the dent did not get fixed perfectly, but good enough to no longer damage the seals. I also used a whole bunch of fine sandpaper to fix the scratches made by the piston on the dent. When I put the piston back in I did my best to align the groove on the piston with the dent. I'm not saying you should do this, as I had little hope it would work, plus it was a lot of labour. You have the advantage of having the dent very near one end, so your idea of reducing the rod travel range is, me thinks, better.

No issues with the fluid inlet. So, it would be OK to weld a piece of steel to the bottom of the piston? Should I weld it all the way around or use tack welds? Do I have to worry about the piston warping from the heat? I'm an OK welder, not a good welder. I'll probably be using a mig welder.

 

[iko]

Depending on what distance we're talking about, maybe just put a few washers under the piston bolt would do it. Using a slightly longer bolt if the distance is more than maybe 1/2".

 

[Swetz]

Should I weld it all the way around or use tack welds?

Don't weld it! why would it need to be welded?

Look for stroke control spacers. See below for an example.

https://www.agrisupply.com/stroke-c...923/?msclkid=745790d2f1191d38f44ef31814322ba0

If I am reading this correctly, the new seals will need to pass the dent....that aint happening without damaging them.

 

[Delmer]

I'd see if there's any way to hammer out the dent, file out, sand smooth etc. before modifying the piston. Obviously it's a small dent, and it's already worn off to some degree, it doesn't have to be perfect, just smooth enough. Or look for a used or aftermarket cylinder.

 

[joe--h]

You're not reading it correctly. He needs the spacer in the end of the cylinder to stop the piston before it hits the dented area.

Joe H

 

[Swetz]

You're not reading it correctly. He needs the spacer in the end of the cylinder to stop the piston before it hits the dented area.

Got it!

 

[iko]

Interesting, this product seems to go on the rod outside the barrel basically stopping the rod going all the way in.

https://www.agrisupply.com/segmented-stroke-limiter-aluminum/p/84744/

I suppose I'd be worried it gets damaged over time though.

 

[alrman]

The dipper barrel is reasonably short, can you reach the dent with your hand?
If so, being down the bottom of the cyl, I would consider using a die grinder to remove the lump.
Using an emery tape drum wheel will give a fairly smooth finish. (not a flapper)
Bigger diameter will work best - (around 2 inch)
Trouble is, you can't see what you're doing with your arm down the tube......

Goes without saying you will need to flush the cylinder after the repair job.

 

[Doug580l]

Don't weld it! why would it need to be welded?

Look for stroke control spacers. See below for an example.

https://www.agrisupply.com/stroke-c...923/?msclkid=745790d2f1191d38f44ef31814322ba0

If I am reading this correctly, the new seals will need to pass the dent....that aint happening without damaging them.

Cool! I think those could work. I've searched for a little while but can't find any big enough, 2.5". Biggest I could find is 2".

 

[Tugger2]

Id say remove the dent . Losing a bit of stroke is going to affect the the travel of the stick. Proper fix would be a re tube . But die grinding ,maybe a good honing after might do it. A creative Machinist might make a couple of guide sleeves up to fit the good part of the barrel and run a boring bar down there and remove enough to allow for a good honing.

 

[Doug580l]

The dipper barrel is reasonably short, can you reach the dent with your hand?
If so, being down the bottom of the cyl, I would consider using a die grinder to remove the lump.
Using an emery tape drum wheel will give a fairly smooth finish. (not a flapper)
Bigger diameter will work best - (around 2 inch)
Trouble is, you can't see what you're doing with your arm down the tube......

Goes without saying you will need to flush the cylinder after the repair job.
View attachment 278225

Interesting. I can just barely reach it with the tips of my fingers now, but the length of the die grinder would help with that. Might be difficult to see what I'm doing. Do I have to worry about the wall of the barrel getting too thin? Maybe weld the indent from the outside first?

 

[Doug580l]

I'd see if there's any way to hammer out the dent, file out, sand smooth etc. before modifying the piston. Obviously it's a small dent, and it's already worn off to some degree, it doesn't have to be perfect, just smooth enough. Or look for a used or aftermarket cylinder.

From what I could find, the cheapest aftermarket barrel was about $1100. For the complete cylinder $3300.

 

[alrman]

I wouldn't weld it, depends on the dent.
I wouldn't think it would protrude into the cylinder more than 1mm or so?
The barrel wall thickness is at least 5mm.