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

[Tugger2]

Welding the dent up outside might distort the barrel. whats the wall thickness of the barrel? The emery drum looks like a good chance to smooth a small dent . Its so close to the end that without a professional hone you wont hone much. Losing a bit of the wall down there wont be too big a problem. If it is ,your back to a machine shop type retube or a new barrel which are the proper fixes.

 

[Doug580l]

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.

Yes, I just looked at it again, just need to take a little off, 2mm at the most.

The only time that the piston would travel to the dent is when the cylinder is within 1.75" of being completely retracted. That will happen, but only be accident. As a habit I try not to retract it all the way.

I did a "test run" to try and tell how difficult it would be to see what I'm doing. I don't think I'll be able to see hardly at all. Maybe the top of my hand above it. I was thinking that I could use some steel shim and cut a little hole in it for the bump to keep from damaging the surrounding areas too much.

I'm still considering welding a 1.75" long piece of round tube to the bottom of the piston. 4.5" od and 3.5" id. One of my concerns with doing that is if it's not perfectly straight it might damage the end cap when completely retracted and cause it to leak.

 

[Vetech63]

Pettibone for years used castle nuts on their fork cylinders. They would weld a spacer on the castle nut tips to prevent the cylinder from collapsing all the way. It works for a while but that spacer would eventually break off and trash the entire cylinder. I would sand that hump down if I were you.

 

[Delmer]

A STRAIGHT flat file, or round straight file, with the ends covered just enough that it will not file a flat surface, might file the hump out without extending past the damaged area. A chrome cylinder rod can be carefully smoothed with a flat file, as the file will ride on the chrome and cut only the hump, the inside cylinder will be softer than chrome, so even a few layers of paint might be enough to cushion the ends of the file to keep from digging in.

Valve grinding paste could also be used once it's closer to the final dimension, but probably not needed, sanding would be close enough.

 

[Jonas302]

Spacer is a good idea if your ok with loosing the stroke I've shortened cylinders that way before but for other reasons

There is no possible way your going to reach to the bottom of a dipper cylinder tube and hand machine a hump with out that you cant see with out damaging the sealing surfaces

It might be best to bring it to a local small shop machinist so they can cut the tubing strait weld it on and clean it up on a lathe if desired probably cost 50 dollars

 

[Swetz]

How about a shaft collar on the outside of the cylinder with relief where it would contact the wiper seal? Just clamp it on at the rod end.

 

[joe--h]

Couple of these on the outside might be easiest.

https://www.mcmaster.com/split-shaf...piece-shaft-collars/clamping-two-piece-shaft-
collars-9/

2" no problem.

Joe H

 

[Doug580l]

A STRAIGHT flat file, or round straight file, with the ends covered just enough that it will not file a flat surface, might file the hump out without extending past the damaged area. A chrome cylinder rod can be carefully smoothed with a flat file, as the file will ride on the chrome and cut only the hump, the inside cylinder will be softer than chrome, so even a few layers of paint might be enough to cushion the ends of the file to keep from digging in.

Valve grinding paste could also be used once it's closer to the final dimension, but probably not needed, sanding would be close enough.[/QUOTE

From what I can tell, the bump goes to within about 1/4" of the bottom of the barrel which could make it difficult to get to all of it with a file. It's longer than I initially thought too and there's a rough area in front of it that needs attention. All in all maybe an inch and a half or more long. Kinda making me lean towards shortening the stroke.

 

[Doug580l]

How about a shaft collar on the outside of the cylinder with relief where it would contact the wiper seal? Just clamp it on at the rod end.

I keep changing my mind on what I should do, but the shaft collar seems like the safest thing at this point. I need to fill a space of about 4" so maybe a shaft collar on each end and a piece of pipe in the middle. When you say "relief" I assume you are talking about rubber or something on the gland end? Maybe a piece of an old mudflap?

 

[Doug580l]

Spacer is a good idea if your ok with loosing the stroke I've shortened cylinders that way before but for other reasons

There is no possible way your going to reach to the bottom of a dipper cylinder tube and hand machine a hump with out that you cant see with out damaging the sealing surfaces

It might be best to bring it to a local small shop machinist so they can cut the tubing strait weld it on and clean it up on a lathe if desired probably cost 50 dollars

Probably the smart thing to do. But I'll consider it anyways. I'm out in the middle of nowhere here so very little to choose from. I tried to get someone to look at a small job a year or so ago and never got anyone to return my call. I might try again tomorrow.

 

[Doug580l]

Couple of these on the outside might be easiest.
View attachment 278267
https://www.mcmaster.com/split-shaf...piece-shaft-collars/clamping-two-piece-shaft-
collars-9/

2" no problem.

Joe H

Are these strong enough to stop the cylinder on their own or do they have to be up against the end of the rod?

 

[joe--h]

I'd guess no, that's not what they are intended for. They do list some that are extra grip clamping, but it's only because they have a larger diameter bolt. Can't imagine anything that would be able to resist the hydraulic pressure unless it was welded on.

He's saying 4" now, that's more than I had thought it would need, but still doable. Seems like that's really going to shorten the dipper movement. Might be time to get a new tube welded in.

Joe H

 

[Swetz]

I need to fill a space of about 4" so maybe a shaft collar on each end and a piece of pipe in the middle. When you say "relief" I assume you are talking about rubber or something on the gland end?

Not rubber, rather grind the collar. You do not want to drive the collar up against the wiper seal, or it will be damaged. I would grind metal away, on the collar that will contact this seal. In other words, if you gang 4 of the collars on the rod, only the one that goes up against the wiper seal needs to be relieved so that it will not contact the seal.

Here is another option:
https://www.surpluscenter.com/Brand...al/2-Double-Split-Shaft-Collar-1-2768-200.axd

 

[HarleyHappy]

Can you see and feel the dent on the outside?
If you can you may be able to pull that dent with the welder and a jig enough that it will be usable.

 

[Doug580l]

I'd guess no, that's not what they are intended for. They do list some that are extra grip clamping, but it's only because they have a larger diameter bolt. Can't imagine anything that would be able to resist the hydraulic pressure unless it was welded on.

He's saying 4" now, that's more than I had thought it would need, but still doable. Seems like that's really going to shorten the dipper movement. Might be time to get a new tube welded in.

Joe H

The 4" is what I need at the end of the rod to shorten the stroke by about 1.75". If I weld something to the bottom of the piston it will be 1/75".

 

[Doug580l]

Not rubber, rather grind the collar. You do not want to drive the collar up against the wiper seal, or it will be damaged. I would grind metal away, on the collar that will contact this seal. In other words, if you gang 4 of the collars on the rod, only the one that goes up against the wiper seal needs to be relieved so that it will not contact the seal.

Here is another option:
https://www.surpluscenter.com/Brand...al/2-Double-Split-Shaft-Collar-1-2768-200.axd

Oh, OK, I understand now. The rod is 2.5" diameter, couldn't find any that size at the surplus center. Nice prices though. I'm thinking of using 2 collars and putting something between them to make up the distance. Might have to weld something on top of the rod because it widens out there and the collar might be forced open or break if too much force is put on it.

 

[Doug580l]

Can you see and feel the dent on the outside?
If you can you may be able to pull that dent with the welder and a jig enough that it will be usable.

Interesting. Here's a picture, there are actually 2 dents.

 

[Tinkerer]

Putting anything on the rod to restrict the length of the travel will pound the crap out of the gland.
That in turn will put a lot of stress on the gland and barrel threads.
A better alternative would be welding travel stops on the bucket linkage if that is possible.
IMHO of course.

 

[iko]

Since we're not done with the possible solutions I'm still thinking that shaving a millimetre off the interior dent is the best long term solution. I wonder if a cylinder ridge reamer would not be enough to shave a little there. Then just sand paper taped to a 2x4 to smooth it out. The way I smoothed mine out, and we're talking about 30 something inches far from the opening, was to tape good quality sandpaper cloth on top of a foam on the end of a 2x4. There was a lot of rubbing and my arms hurt after but in the long run you forget that.

 

[Tugger2]

Good to see that picture of the dent. If it were in my shop id clean those dents on the outside first, then id weld them up . I know thats a reverse on my thoughts above. Then id chuck the cylinder in the lathe ,id bet theres a center hole in the pin boss . Clean up the weld on the outside .then machine the weld out until the bottom of the cylinder can be removed . once the bottom end of the barrel is open ,set up the steady rest and dial in the bore . A careful touch with the boring bar on the dent ,then a polish with the die grinder and flap wheel . If it wont dial in right the die grinder with a stone will remove the dent then clean up with a flap wheel .Its easy to check the dents with an inside mike when the end is open like this . Plug the bottom back in and re weld . All this said you need a creative machinist .
Id avoid stops on the rod that going to pound the gland and you will lose travel on the stick . An inside stop that will work on the piston will be as much work as machining the barrel of the end and you will still lose travel on the stick.