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

[Doug580l]

I'm in the process of resealing the dipper cylinder. It was leaking from the gland seal. Otherwise the cylinder worked fine. I assume that because of 2 bad areas I need to replace the piston, or maybe it doesn't affect it. If so, any recommendations where to get it from? Broken Tractor has one for about $270 delivered. I've heard of them but don't think I've ordered from them before.
Had no idea that the seals/rings would be so bad. I've done several other smaller cylinders on the machine and none of them looked bad at all.
Also, should I be worried about contamination from the old seals? As of now everything works fine on the machine. Should I just change the hyd. filter after running it for a while?

Thanks,
Doug

 

[alrman]

The real question here is - what does the inside of the cylinder look like??

That bearing looks like it has melted - has a welding repair been done to this cylinder?
The gouging on the piston would indicate that there has been something metalic in there at some time earlier, as you would expect the seal to show damage as well.
I think someone has maybe resealed the cylinder & reused that piston - but that doesn't explain the melted looking bearing??

 

[Vetech63]

If you have any gouging inside the cylinder barrel then it’s not going to matter…..reuse or new will still rip the seals apart. Feel with your fingers down inside the barrel bore. Use a flashlight also. You may need a replacement cylinder.

 

[DMiller]

Or at least to have a shop full length hone.

 

[Doug580l]

The real question here is - what does the inside of the cylinder look like??

That bearing looks like it has melted - has a welding repair been done to this cylinder?
The gouging on the piston would indicate that there has been something metalic in there at some time earlier, as you would expect the seal to show damage as well.
I think someone has maybe resealed the cylinder & reused that piston - but that doesn't explain the melted looking bearing??

From what I can tell, the cylinder barrel is fine. I can't see or feel any damage.

Can't see any signs of any welding being done, although it's still connected to the machine so I can't see all of it. The bearing looks pretty much the same all the way around.

 

[DMiller]

Could be fluid cuts but most likely a used piston installed or reused in a good tube.

 

[iko]

Is it possible you damaged the piston when you pulled the rod out? Those indents on the outer side of the metal part of the piston look like grip marks more than rubbing/scraping. In any case, you need to smooth out the piston because it will scratch the interior of the cylinder when side forces on the rod pushes it against the wall. It should rarely happen but still. With new seals it should be fine I think. But you really need to be sure the interior of the cylinder is smooth.

 

[Tugger2]

Any small dents in the barrel?

 

[iko]

Good point about the dent. This is what my piston looked like from a dent in the barrel.





And then fixed up.

 

[Doug580l]

Is it possible you damaged the piston when you pulled the rod out? Those indents on the outer side of the metal part of the piston look like grip marks more than rubbing/scraping. In any case, you need to smooth out the piston because it will scratch the interior of the cylinder when side forces on the rod pushes it against the wall. It should rarely happen but still. With new seals it should be fine I think. But you really need to be sure the interior of the cylinder is smooth.

It was definitely awkward removing the rod, but I never directly touched the piston. I was either up on a ladder with a hammer or pulling on it with an engine hoist. When it finally did pop out, it landed on the piece of wood holding the barrel up. Not looking forward to putting it back in, or removing the piston nut. The service manual says the torque on it should be between 2400-2800 ft.lbs.

From the comments from several different guys, it seems that I really need to check out the barrel more carefully. The worst area of damage on the piston would put it at the very bottom of the barrel.

 

[iko]

Oh wow, the piston on the boom cylinder of my 680E was 1000-1200 ft-lbs according to the service manual. With 2400-2800 ft-lbs I'd think you're in the 1" drive breaker bar territory. What socket size for that bolt?

 

[Doug580l]

Oh wow, the piston on the boom cylinder of my 680E was 1000-1200 ft-lbs according to the service manual. With 2400-2800 ft-lbs I'd think you're in the 1" drive breaker bar territory. What socket size for that bolt?

I'ts a 2-1/4" socket. I have a 1" breaker bar but haven't had any luck so far. I've tried hitting the end of the bolt with a sledgehammer to shock it. Using the sledgehammer on the breaker bar-both directions as someone suggested on the forum. Also used heat and about 10' out with pipes for leverage. Had my wife help with that. Nothing so far except that everything is bent now.

I'm thinking about maybe using the mini ex to apply pressure to the breaker bar or using a floor jack. If I use the floor jack, I'm going to need to drill a couple of holes in my work bench and bolt down the end of the rod with some metal strapping to keep it in place. Also thinking about a 2500 ft. lb 1" air impact from Harbor Freight since I have several more leaking cylinders to repair.

 

[Nige]

If all the nuts are the same size why not cut yourself a wrench from some 1” plate.? That plus liberal application of an FBH (20lb minimum) should shake the nut loose.
Applying the mini ex to the end of the breaker bar is only going to break something IMO, and if pieces of hardened steel start flying then you’d better be good at dodging the shrapnel.

 

[Delmer]

You need a wrench cut out of 1/2" or bigger plate, then use a cheater pipe on that. heat the nut to 300F if there's a possibility of locktite. hold a big hammer on one side of the nut and smack the opposite flat with a slightly less big hammer, repeat all the way around the nut.

Those seals are something I've never seen. Possibly from air burning them with the oil under compression (diesel engine compression roughly 400PSI, hydraulic cylinder compression roughly 3,000PSI !!! oxygen no good) File those burrs round, then sand so the surface is smooth and round, don't worry about the grooves and scratches, just so it doesn't gall the cylinder. Inspect that cylinder bore with a borescope, mirror and flashlight, whatever it takes to find the damage. I'd have no problem reusing that piston, assuming this isn't full time working machine. The cylinder is highly suspect.

 

[Tugger2]

I used to fix some case stuff back when a 580C was the new deal. The cylinder barrels were pretty light. A rock finding its way between the barrel and the stick or a light bump against something solid would dent them.
Welds on the top fitting by the glad would leak sometimes from new,guys would run a pass around them and the gland would never seal. I fixed lots of them by taking a center punch to the weld and peening the leak shut . My neighbor asked my if i could weld a leaking fitting on the thumb cyl on his 200 Hitatchi ,tried the old center punch trick and hes been good for monthes now.
This dosent solve your issue with that packing but gives you an idea how finicky these thin wall barrels are to impact and welding.
You might have had a piece of foreign material run thru that packing if theres really no dent.

 

[iko]

I'ts a 2-1/4" socket. I have a 1" breaker bar but haven't had any luck so far. I've tried hitting the end of the bolt with a sledgehammer to shock it. Using the sledgehammer on the breaker bar-both directions as someone suggested on the forum. Also used heat and about 10' out with pipes for leverage. Had my wife help with that. Nothing so far except that everything is bent now.

I'm thinking about maybe using the mini ex to apply pressure to the breaker bar or using a floor jack. If I use the floor jack, I'm going to need to drill a couple of holes in my work bench and bolt down the end of the rod with some metal strapping to keep it in place. Also thinking about a 2500 ft. lb 1" air impact from Harbor Freight since I have several more leaking cylinders to repair.

2800 ft-lbs torque at the bolt means about 280 lbs on the end of the 10' handle. Like others say here, you're in the territory of "can get hurt badly" when things slip, break, or shatter. My long wrecker bar bent quite a bit, then broke at the very end, so the end on my side sprung into my palm; hurt for days. If I were you I'd try once more with heat and about 300 to 350 lbs at the end of that 10 foot breaker bar. But I'd make sure the rod around the bolt is hot to the touch all around. The impact you consider getting most likely will do it, but you better have a lot of air flow for it. Good luck and keep us updated, hope you get it out safely with no issues.

 

[joe--h]

Jonas302 in this thread https://www.heavyequipmentforums.com/threads/hydraulic-cylinder-piston-bolt-removal.98782/ posted a picture of what Delmer suggested above.


Joe H

 

[Doug580l]

If all the nuts are the same size why not cut yourself a wrench from some 1” plate.? That plus liberal application of an FBH (20lb minimum) should shake the nut loose.
Applying the mini ex to the end of the breaker bar is only going to break something IMO, and if pieces of hardened steel start flying then you’d better be good at dodging the shrapnel.

The head of the bolt is recessed and there is only 3/8" sticking out. Is that enough? Also, what would I use to cut the plate with?

 

[Doug580l]

You need a wrench cut out of 1/2" or bigger plate, then use a cheater pipe on that. heat the nut to 300F if there's a possibility of locktite. hold a big hammer on one side of the nut and smack the opposite flat with a slightly less big hammer, repeat all the way around the nut.

Those seals are something I've never seen. Possibly from air burning them with the oil under compression (diesel engine compression roughly 400PSI, hydraulic cylinder compression roughly 3,000PSI !!! oxygen no good) File those burrs round, then sand so the surface is smooth and round, don't worry about the grooves and scratches, just so it doesn't gall the cylinder. Inspect that cylinder bore with a borescope, mirror and flashlight, whatever it takes to find the damage. I'd have no problem reusing that piston, assuming this isn't full time working machine. The cylinder is highly suspect.

Shouldn't I be able to feel if there's a bump in the barrel rather than using a borescope?

 

[Doug580l]

2800 ft-lbs torque at the bolt means about 280 lbs on the end of the 10' handle. Like others say here, you're in the territory of "can get hurt badly" when things slip, break, or shatter. My long wrecker bar bent quite a bit, then broke at the very end, so the end on my side sprung into my palm; hurt for days. If I were you I'd try once more with heat and about 300 to 350 lbs at the end of that 10 foot breaker bar. But I'd make sure the rod around the bolt is hot to the touch all around. The impact you consider getting most likely will do it, but you better have a lot of air flow for it. Good luck and keep us updated, hope you get it out safely with no issues.

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.