So I tore into the job of repacking my leaky stabilizer cylinder this weekend and when removing the rod and piston, the old guide rings fell right off in pieces. First time Id seen that, figured they were just wore out and brittle. When I took a peek down the cylinder bore however I saw a ding in the wall. After fitting the piston with only the new guide rings I slipped it down the bore and cannot push it past the area with the ding. The ding is about the size of a quarter, but I think possibly it was crushing the old guide rings as they passed. Rather than have this happen to my brand new guide rings I was thinking of ways to possibly smooth over this ding somewhat. Any body ever deal with this? I was thinking of spot heating the ding with the torch and sort of swaging it back into shape by forcing a 100mm mandrel down the bore past it. What do yall think?
I had a dent on one of mine when I bought it. I knew it was an issue. I took it to a hydraulic shop and the made a new cylinder and piston. Was not cheap but less than half the price of a new unit.
Based on my experience….can you massage that ding down where the piston will move past it? Yep. Will it hold seals? For a short while yeah. The bigger concern for me is contamination if/when that thing starts making metal. Anything you run down the barrel to repair the ding runs the risk of damaging another spot. It will depend on how much you use it as to how adventurous you decide to be. If you make a living with it then get a new barrel. If it’s a weekender or low use machine you might run it for a long time with no issue. I guess the good thing is stabilizers don’t make a lot of cycles like the stick or dipper would. It’s also a good ways in there, I suppose you could do your best to keep the cylinder from going that far unless absolutely necessary like during transport etc.
Just get a new barrel made. A good machine shop or hydraulic shop should be able to make one easy enough. You should be able to reuse the piston, rod and gland.
Hone it you have nothing to loose.
If it was mine and money was tight I'd get a couple of grinding stones and reach down there with a die grinder and cut it out. An old school ridge reamer might do a good job also. Then I'd polish it with flap wheels, bore polishers, or something similar. I think anything but a rigid hone such as is used for cylinder bores would just dig a hole around the dent. But having it rebarreled would be better.
I'm going to try the plug rout first. Ill fix it to a length of threaded rod so if it gets stuck i can thread a nut on and draw it out. then maybe a quick finish honing. Like Billrog said, Nothing to lose! I'll let you know how I make out.
What about a hard wood plug? Could add a little heat to the dent from the outside.
Does your piston show scratches or galling from contact on that bump? The seals probably came apart from age, unless it was obviously gouged in that spot. I don't think I'd try a steel plug, unless you use it as a backer to hammer out the dent from the outside. Maybe three wedges that could tighten up with a threaded rod, then hammer, but that's too complicated. If that was the outside of a rod that was gouged, we'd use a flat file held lightly on the chrome to remove the high spots before sanding smooth. I would try something like that, a flat file with thin tape front and back so it doesn't dig at the ends, but will flatten the peak of the dent. Then when it's as flat as you can get, sandpaper or flapwheel for smoothness. If you could find or make a suitable cylinder to fit closely, a piece of sandpaper taped on would work also.
I have made satisfactory, and a lasting repair as you may well too using a large tailpipe expander tool such a shown here: https://www.harborfreight.com/exhaust-pipe-expander-kit-57586.html?_br_psugg_q=pipe+expander I pushed this tool into the barrel and had a partner, (grand daughter) warm the dented area of the barrel with a torch till dull red then hold the heat in a circular fashion while I tightened the tool. The dent relaxed easily with the direct pressure applied and the bore wasn't even scratched I could tell. I did not use an impact wrench, only applied pressure by hand to expand the die. The rubber rings that kept the die shoes together did not survive the heat but I would consider them expendable, or sacrificial in nature. This was on a hydraulic tail trailer and the barrel was 1/4" thick. I talk to the gent/owner routinely and it hasn't given any problems in about eight years now.
Yes the piston has a small flat where i assume it pushed past the dent the first few cycles. So im sure the wear bands were crushed from that. the seals seemed to just push past it.
These look to have potential. I like the fact that i would not have to force them down the bore. less likely to scratch. And I could use them for other things! I think my cylinder walls are also around a 1/4 inch thick. Thanks for the link
No worries and I hope you have similar and acceptable results. I strongly recommend you utilize a helper with this to keep watch on the dent as it raises. It will need the flame played over and around the area constantly. I have a 53' Kaylyn-Siebert sliding axle trailer coming in later this spring that was picked up by a forklift and dented/distorted both axle sliding cylinders underneath with the forks. I'm hoping to have similar results rather than retube the cylinders.
Boom cylinder on a Case 580K backhoe got shot best I can figure. Ruined the piston. Hydraulic shop made a new tube & a new piston. Cost $1250 . Knowing what I know now, I got off cheap.
My boom cylinder rebuild was $1400. New chrome rod, cylinder made and piston made.
Bad boom
WOW! I've never seen an expander tool that went that large. I will have to file this away in memory.
Whelp, I ended up cutting a small radial section of 4" pipe to use as a sort of sanding block. Then with lots of elbow grease applied i used some emery cloth to work the hump down to the point where the piston and guides would pass without hanging up. Then polished my handy work and put it all back together. The ding was about 15" down into the barrel. The seal seat area in the gland nut was rusty and pitted so i had to do the same JB repair I did for the loader cylinders. Seems operate fine now. I dont see any leaks.