Any suggestion on what to do with this little punched hole to stop the nut from coming loose? I was thinking of possibly trying to just pry the edge up out of the way from the nut and hoping it would not break when I press it back down after replacing the nut. I'm guessing that Loctite on the nut might not hold up inside a hydraulic cylinder?
Just back that nut off. It'll restore the threads. When you got it off, file those threads down a hair. It'll be fine. Don't dimple in the same place. That's asking for a flake to cause you further grief. Good luck
Thanks! Does it take any kind of special hardened punch to make a new dimple? Or should my Harbor Freight punches do the trick? And maybe I could experiment by attempting to Dimple in the middle of the piston rod?
The threaded end should be just plain old steel. I don't know if HF punches will do the job . I know snap on and craftsman punches will. All you're doing is creating an interference fit so that the nut cannot back off. Personally, I like to ding the nut . When you torque her down smack it again on an angle in toward the threads. Locked up tighter 'n dicks hat band.
YUP.. just unscrewing the nut will be fine.. Use some Loctite on the threads when you reassemble it & tighten the sh*t outa it.. The torque on some of them are upwards to 600 ftlbs.. 300 is the "norm" tho I think.. THATS WHY someone "staked" it.. probably didn't have a TW that went that hi.??
What kind of machine and what function is the cylinder used for? Staking a nut does virtually nothing to hold the nut from coming loose. I usually take a die grinder to the part sticking out the farthest to keep any damage to the nut to a minimum. Find out a manufacturer's torque specification if possible when reinstalling. If not available then consider the amount of pressure used to operate that particular function against the size of the nut. I'm guessing from the photo it is around 2 1/4 inch or larger and 600 to 1,000 foot pounds would be more in the range for a system operating in the range of 3,000 to 5,000 PSI hydraulic pressure. Locktite 262 would be my preferred liquid to hold the nut.
The nut takes a socket 1 and 7/8 inches. The cylinder is the basket leveling cylinder at the end of the final boom on a marklift 62 aerial lift. I just got a large set of impact sockets to fit it, but not sure if my half inch air impact driver will have enough torque. I was unable to crack the nut with a 3-foot breaker bar
Doubtful a 1/2 inch impact will work.... get a 8 foot pipe for your breaker bar, if the 1/2 inch drive holds up it might work... you'll probably need a little bigger tooling or at least a pretty large pipe wrench and extension pipe.
Half inch drive is not going to cut it .You will need 3/4 or 1 inch drive to get it off and retorque it back on to spec .
Take it to a cylinder shop with a bench. They can break it loose and tell you the torque. Better yet have them repack it while you are there.
Some very good advice there Unless you are really wanting to save a few bucks and your time is worth next to nothing a shop can do a cylinder like that in less than a couple hours... full service.(provided they aren't backlogged a week or two) Among some other benefits of a shop set up for these things, they can also hone and polish the can and rod while fixing any other issues that may be in there to make sure it lasts a long time. They can also do a proper pressure test to make sure it is safe and 100 percent ready to do it's job There is a lot to be said for having the right tools for the job, makes it nearly impossible to cause more damage to the cylinder wile trying to work on it... of course if you have some decent fab skills and are willing to do a bit of research it really isn't that hard to make any tools you will need And most shops I have used in the past use good parts from reputable suppliers for the seals,wipers and other wearable parts... not some odd ball import funky rubber that leaks two months after you install the cylinder... Anyways it really isn't that hard to work on these things... BUT you really need to know what you are doing before you start... there is lots of info around for those that wish to DIY it but remember it isn't something that everyone can do the proper way....
I give you a pat on the back for making it THIS FAR.. Theres "normally" 3-4 PAGES of people asking HOW TO get the cyl. off & HOW TO get the gland nut off & WHERE to buy the tool.. I did have to chuckle a little, when you said you tried a 3ft breaker bar tho.. You came on here w/ a decent question & a very clear picture for your [almost] 1st post.. {hell} I cant even do that..Lol BTW> some of those threads are "backwards", so watch out for that.. good luck.
thanks for all this great info! Yep the threads are normal not backwards. Also my half inch air impact did not have the torque so I'm going to be picking up a 1-inch impactor tomorrow. I couldn't even get the wheel lug nuts off with my half inch air impact, so I know that all of these heavy-duty tools will be getting put to use. And I will be taking all of these disassembled parts to a really reputable hydraulic shop locally. I did not see the Loctite 262 on my Loctite list, so I guess I will just Google it or see if this local hydraulic shop has it. Does that Loctite 262 have to be heated in order to remove it, in case I have to remove that lock nut again?
272 is for 3/4-1 1/2" thread fasteners.
Not to hijack the thread but.. I've always gone by the color when using Loctite & never bothered to learn the #'s..The #'s in my experience, kept changing for the same thing.. So I just kept up w/ the colors. Blue is> service removable.. the "fastener" is held in place, but if it has to be removed again, it can be, with some force. Red is> "in-there" & cant be removed without a small torch.. Green is> Permanent.. used for loose bearing races, bushings & such.. Then theres another "thick" Red, used on the threads of oil/fuel line fittings when screwed into aluminum.. Not to be confused w/ White pipe dope thread sealer.. I think they{Loctite} tag it as, "Hydro. thread sealer".. Whenever ANYBODY asks me about WHAT Loctite to use.. I always say, "A COLOR".. & 99% of the time its BLUE.. BUT.. in this instance I'd have to say, RED.. its gonna be a cold day in hell when someone has to get back in there.. & given the amount of torque that needs to be applied to the nut.. if you miss the mark, you def. want something holding it/ helping it.. Good luck w/ the repair..
Wow, great information. So just curious would that color scheme apply to other brands of threadlocker besides Loctite?
What about using Loctite on hydraulic line connectors like to the holding valve in this picture? I actually discovered that this threaded nut was loose and only held on by a couple of threads and it was leaking oil, and the location of this holding valve was on the aerial lift basket leveling cylinder which was set inside the final boom and set back a good 12 to 18 in from the end of the Boom thereby making it really difficult to see and reach. If you would use Loctite on those threads, which color would you go with? Just w ondering if you had to use the red and a torch to get it off if that heat from the torch would damage the holding valve?
I cant speak for other manuf. as I've only used Loctite.{color} Check one of the fittings.. they might have an oring or nylon insert on the nut.. if so, I prob. wouldn't use anything on them. You'll be able to tell once you remove it, if anything had been used on the threads..
Those look like JIC/SAE fittings should not need any thread locker on them. Now if you have one of those that has some minor damage and is seeping oil there are copper gaskets available that can solve that problem. Kind of hard to find but I know Cat for one does sell them if you can find a parts guy who knows where to look up the numbers. Usually the best fix would be to replace the fitting and line but sometimes that is not as easy as one would like! Edit: Took a bit of searching but finally found the information on the copper seals for JIC fittings! Did anyone else know that there was a torque spec' for a hose fitting?
Wow this is great to know. But my fitting was leaking simply because it was loose. I just purchased this used aerial lift, so I assume the nut either came loose on its own or the prior owner's mechanic forgot to tighten it down or something. I would not normally put threadlocker on a hydraulic fitting like this, but since this fitting was in such a remote hard-to-reach location, that's why I was thinking thread lock.
Understand, guess my thought would be if it's in a "remote hard-to-reach location" while the Loc-tite may prevent it from coming loose when you did not want it to come loose it might also prevent it from coming loose when you did want it to! Could be one of those "Dammed if you do and dammed if you don't" situations. My personal feelings would be that it probably came loose due to the last guy's error. JIC fittings like that, in my experience, don't come loose if properly tightened unless some outside force is putting a twisting strain on them. The one you are pointing to in the picture should not be subject to anything like that. As we do in the motorcycle forum I post on often "Blame it on the PO!" PO= previous owner!
Well I finally got the nut off with a 1 inch air impact. What I can't believe is how the inner seal on the cylinder cap was extremely deteriorated, picture below, and just flaked apart when I touched it. Now I am wondering how many other hydraulic cylinders on this machine are in the same condition???
I'll take a stab at it..>> ALL of them.. that end is exposed to the elements.. The "wiper" takes a lot of abuse.. its job is to wipe the rod clean so that dirt, mud don't get in the cyl. & it sits there pooling up w/ water & drying out when the sun hits it..
Hate to give you the bad news but as pump guy in SC says if they are all the same age they are probably in close to the condition But at least the next one will be easier as you know how to do the job! By the time you get to the last one you will be changing your online name to thecylinderguy !
You can get by without it, but this little tool will certainly make stuffing that inner rod seal a lot smoother.
ANYTHING would help FWF.. that seal is a nitemare.. Ron, if you get even slightly good at doing cyl. rebuilds, you can make some GOOD money.. The shops charge upwards of 1000.00 to do one.. I have a buddy that LOVES to do them & I have to force him to take 100.00.!!! I buy the 30.00 kit tho, but still.!!!
Oh and one more thing before I forget to mention Sharp Tools have no place in cylinders, glands, Pistons or packings use no Sharp Tools only dull blunt plastic possibly instruments. If you have to use a sharp tool for picking prying stabbing whatever make sure that you wrap the shank of the tool with a heavy coat of black tape or something to protect your Chrome finishes
Unfortunately I never heard of those tools till maybe the last year or so I was working at the shop. And being a cheap SOB I never bought any of them! But then most of the cylinders I did work on back in the day were on the larger size and getting the seals in you had a bit of room to work. Now if I owned a used machine with half a dozen or more cylinder that would eventually need doing I would definitely be getting some of them. Did a Google search on "hydraulic cylinder seal installation tool" and it comes up with several different makes of those tools some seem almost too cheap. The more expensive ones might be worth the money if doing several cylinders a week but for someone only doing a handful of cylinder on one machine the cheaper ones might be just the ticket.
My thoughts exactly. I still don't own them. Can't justify. But I did borrow one, once. For a smaller 1" rod cylinder
The ones that I've personally had my hands on were off a 580bCK.. THAT tool woulda came in very handy.. The stabilizer's were no fun & took some patience.. They ended up getting "snatched" outta my hand so the pro could do it..lol. I guess he got tired of watching me struggle..Lol I was just tryin to help.. Geez.. Lol
Yeah I kind of realized after getting the seals off with screwdrivers that I put some small scratches in the aluminum piston and cylinder cap. But the guy at the hydraulic shop said they were small enough not to worry about. But I will use plastic next time. I could not believe how expensive the outer seals on the piston were, $20 each. Also said 2 just tip the seals in transmission fluid and push them on by hand.
I'm curious of what the shop charged?? Lol.. THATS WHAT I tell people too.. after you've done it 1000 x, THATS all you have to do,,lol "I" can get a flex ring on a weight retainer in less than 10 seconds flat.. it takes the average Joe, 10-15 minutes.. & some have to get on the internet to figure it out.. Lol Glad your getting it taken care of..
Well I got these o ring seals off of the piston but I'm having a real problem putting the new ones on . I'm afraid that I might damage them by trying to pry them back on with a couple of screwdrivers . Any advice ? Should I heat them up in the oven or with a hairdryer to stretch them out a little bit? Or maybe put them in some transmission oil and heat up the container with the transmission oil and the O-rings in the oil? The guys at the shop said that they can push them on with their fingers , but I don't think I have the strength to do that.
Put the seals in hot boiling water for a bit .Than put on piston .
I wouldn't pack that piston. It's all scratched up. I'd polish that rascal with some Emory cloth. I'd also run my hands up and down that barrel looking for scratches that need to be honed out. Just being honest. Don't want to see you waste materials and labor. BTW , did you reseal the piston to the rod? There's an o-ring seal in there.
Okay good advice with the hot water. Thanks! And just to make sure I can't remember but I think the fat end of each o-ring which contains another ring is supposed to face away from the center of the piston correct? To smooth the scratches on the piston, what about black wet dry sandpaper ending up with 400 grit? I will check the cylinder for smoothness. But wondering how the center portion of the piston could be all scratched up when the outside edges by the o rings are not scratched up? Wondering if it came that way from the factory? The inner piston seal to the rod was replaced by my hydraulic shop.
Not the inner rod seal, the rod to piston should have an o-ring. The finer the paper, the better. Doesn't look like it needs a lot. I'm just real particular about the stuff you never see.
Oh yes, I replaced the rod to piston o-ring which was really cheap and easy to put on. I replaced it even though the old one looked okay. It just looks like a standard round O ring, right?
Yep, some folks just overlook it. . keep going, yer doing great
It make the seals pliable and easier to handle with out being slippery .
And so does the part of the O-ring with the smaller o-ring insert face towards the outside of the piston as pictured?
If it has a "cupped" side, you want those to the outside of the piston. So your finished piece would resemble an hourglass. If that makes sense.
Yes that makes sense. Thank you so much!
Fuhgedabodit
Ok, two more questions. The cupped part of the piston seals protruded about a sixteenth of an inch above the piston edge and it was so tight pushing it back into the canister that I had to use a 12-ton press to push it in. My own weight of 160 lb was not enough to push it in. And I did disconnect the lines to the holding valve . Should it be that tight? I am also hoping that the cup seals were not damaged as they passed through the canister threaded end. Second question, do I need to prime the cylinder to get the air out of the cylinder and lines? The cylinder pushes and pulls in both directions and also has a holding valve for both directions.
If at all possible, you want to get all the air out. What is usually recommended is to run the rod in and out several times with no load and not reaching end of travel in either direction. I find it easier to just fill both sides of the cylinder on the bench. Bumping end of travel with air in the cylinder will lead to dieseling which will destroy your shiny new packing you worked so hard on. Should not have needed a press to reassemble. Packing must be hella tight. At least she won't bypass. Lol
Did you lube it good before you installed in the cylinder?
No I did not pre lube the cylinder. Guess I should have. The packing was not from the OEM seal kit. It was just what my local hydraulic shop recommended after they measured the cylinder and piston with their micrometer. The old o-ring packing that came out of the cylinder was flat on both sides, but the packing from the hydraulic shop was raised up on one Edge where the second o ring was inserted.
As long as you didn't see little bits of vinyl on the threads when you shoved it through you'll be fine
I did not see little bits of black vinyl on the threads so that is good to hear! I read about dieseling on Google and will take your advice about filling the cylinder on the bench. What if there is a small amount of air in the several inch line between the holding valve and the cylinder? And what about air and the hose between the hydraulic pump and the holding valve? I think the factory service manual said that it was self priming, but now I'm nervous about that. And I also noticed when I took the cylinder apart that there was very little oil in the cylinder. Thanks so much for all of your help!
Just follow the recommended procedure stated earlier. Run the rod in n out at idle slowly going a little further in each direction each time. Eventually you'll run out of rod. Once you've exercised the rod in and out fully 4-5 times, you should be golden. I just didn't want you to put a dry cylinder in and run it to end of travel both ways. That would have maybe hurt something.
Okay so I hooked up the hydraulic lines and exercised the cylinder back and forth a few times and it was working good until two other lines at a different location on the machine blew out and spewed oil. So I am guessing that this reduced the available pump pressure to the basket level cylinder I was testing since it would no longer move in and out. So my question is are all of the hydraulic lines supposed to maintain a certain amount of pump pressure even when their cylinders are not activated? How much pressure? Thanks much!
Displacing the air out of the cylinder moves it to the reservoir which applies some pressure to all the oil in all the components of the system. Usually there is a pressure vent or the cap is vented and will release any pressure over the manufacturer's setting. The pressure is usually one atmosphere or somewhere around 14 to 15 PSI. If you blew out hoses at that bit of pressure you have a whole lot of bad hoses.
Are these hoses by Chance the orange cloth reinforced no metal hoses . If they are and this machine has some age to it I don't think I would trust my life to them as John stated you have a lot of bad hoses more than likely it might be time to just re hose the machine. At least those that are exposed to the sunlight
Yes it is the orange thermoplastic hoses that are exposed to the sunlight and the orange plastic coating was cracked up quite a bit. And I was planning to replace them with standard black steel-reinforced hosing. So if I just loosened up the vented filler cap of the hydraulic oil storage tank, theoretically, should I be able to exercise the basket level cylinder without oil being spewed out from other hoses that are disconnected at other components of the machine?
If your hoses are failing from tank pressure better to let them burst now and I would advise against replacing them with traditional braided hose you lose the insulation properties of the nylon bucket and the fiberglass boom sections. Any path to ground is a dangerous path for you when you're the one in the bucket. Additionally now that we know we're dealing with a man lift ,that uses a special oil it's a very light viscosity Aero oil if I'm not mistaken.
Thanks for that great advice. My 1980 marklift must be a little outdated since the boom sections are metal and the basket is also metal LOL. Anyway the orange thermoplastic lines inside the boom appear good as new. But it is 4 short 12 inch orange thermoplastic lines at the base of the boom that are exposed to sunlight that are cracked up, and those were the ones I was thinking of replacing with the steel braided hose.