First time seal install for me - couple questions, as I already had a 1 1/2 inch impact socket on this bugger with 3/4 breaker bar and a 8 foot cast iron cheater pipe - all I ended up doing was bent the breaker bar - so I am assuming I need to apply heat also - my questions are" is there most likely loctite on the bolt? how much heat will release the loctite? Oxy-Acetylene, or is a big turbo torch ok? Specifically, where do I apply the heat - right on the piston? should I re-loctite, what kind? 404? Anything else I forgot? PICTURE HERE
They can be a pain some times. Even messed up the threads on a couple. Search around the nut to make sure you don't see a little allen headed lock that is drilled through to prevent it from backing off. Can't remember if 580B had that? It is not a good idea to use heat. The piston is right beside it and turns blue too easily. A 1" ratchet with about 15' thick walled pipe will usually knock them ones loose pretty easily. If it does have alot of loctite gona take some work to get it off. When we run across 'em so tight that our 1" impact won't break loose, we have this press designed specifically for high torque rod nuts. This thing cranks out some serious torque! There is usually a dealer or hydraulic shop that will do that for you for 50-100 bucks. Good Luck!
Tloft, I replaced seals on the dipper cylinder on my Deere 310D. It required a 2" wrench. I used a box end wrench with a 8 ft bar on the end and turned it by down pressure of a front end loader. Bent the wrench the first try. I then straightened the wrench with torches and welded two reenforcement bars on the wench. Second try broke the nut loose. There was no locktite on the threads. It was just plain tight. I reassembled without locktite.
The way I do it is a little unorthodox. I get a long pipe that will fit through the pin side. I put the pipe in the hitch hole of my truck. I then get a wooden crate that will support the rod to keep it level, wont scratch it, and hold it in place. I then get either my wrench or socket and rachet and put it on the nut. I then get a pipe and put it on the wrench/socket. I then jump down in the correct direction and it breaks every time. Been through that circus and it is not too bad when you get a method that works for you. I have had several that the 2" impact spline gun would not budge.
Heat can be used, carefully. Use oxy/acetylene gear and #12 cutting tip (or a #15 heating tip) Heat the centre of the head of the bolt (as I did with some of mine) Don't get it too hot. You don't want any colour (redness) or else you have gone too far. The idea is to get the bolt hot enough to break the loctite bond and expand/contract in the ram shaft to release the friction between ram and bolt. Let the bolt/assembly cool until you can place your hand on it for a couple of seconds. Do not use water or air to speed the cooling process. Then have another go with a 1" drive socket/bar and a 10' pipe. I use Loctite 262 when replacing the piston retaining bolt. Oh, and keep the end of the pipe away from the underside of your chin too!
I assume we are talking about the bolt on the end of the piston and not the gland nut on the end of the cylinder tube. My 580D had loctite on the bolt. I pushed the gland up the piston so as not to turn the rubber seals into goo. I used a little propane torch on the bolt head till the piston was a little too warm to hold. Loctite lets go around 140 deg If I recall. I used a method similar to Leon's but used the front bucket for a weight and a piece of scrap plywood for a work surface. 6ft cheater. Set on cheater and banged on it with a 4lb shop hammer. The shock helps. ps I removed all the nylon wear rings from the piston before heating...
I rebuilt 7 (so far) of the hyd. cylinders on my 580B. the technique I used was given to me by my hydraulic supplier, Rich at ABC Hydraulics in Rocky Hill, CT. (had to give him a plug because of all the help he gave me, including waiting after hours over an hour for me to pick up parts) He said to heat the rod bolt head until you see wisps of white smoke. I used Mapp gas. the smoke is the locktite melting at about 500 degrees (per the loctite bottle instructions). I used a 3/4 inch drive socket set I picked up at harbor freight with a 3 foot pipe on the breaker bar about a minute after I saw smoke. After everything cools down, I sprayed the threads on bolt and rod with brake cleaner and blew dry with compressed air. He said to torque them to 275-300 lb/ft after applying a stripe of red (high strength) loctite to the first 5 or 6 threads. (the bucket tilt cylinders were 150 lb/ft. replacing the inner gland seals in those was a bi***--ahem-- angry woman). After the first cylinder, I've found I can rebuild one of the larger cylinders in about 1.5 hours. I found it's easiest if you use the pin to hold the rod on the backhoe where you took it off. I had to dig a hole to work on the dipper stick cyl.
example of working on rod on tractor
wow, thanks very much to everyone for all the help - here's my plan. When I tried yesterday I used bob's way of using the pin to hold the rod where it was mounted to the backhoe bucket while I had the breaker bar, socket & 8 foot cheater pipe on the other end - my only problem seems to be I didn't heat up the bolt - so that's what I plan now - looks like rain tomorrow, if not I will give it a shot .. might have to dodge raindrops - will let you know how I make out. I will use my small acetylene turbo torch to try and localize the heat to the center of the bolt.
No luck OK, here is where I'm at - removed the cylinder & hooked up the rod in it's place to get a more stable work area with less rod movement - I heated the bolt for about 3 minutes, straight acetylene, turbo tip - I figured it was around 500 - I waited about a minute and tried the breaker bar using a 6 foot cheater pipe - no luck, so I let it cool some more until I could touch it, still no luck - I was thinking I may not have had it hot enough - might try melting some cad free silver solder on the bolt head to verify temperature - any more thoughts?
Did you see the wisps of smoke from under the bolt? The head shouldn't get red.I think your solder idea measures bolt head temp not thread temp.I never needed more than 3 foot breaker bar even for swing cylinders.try again.good luck
no bob, I did not get the white smoke, and the head did not get red - I'll heat it longer this time - how long did it take you with the mapp gas?
never timed it. maybe about 3 to 4 minutes. I just went till I saw the smoke. as long as you don't heat the bolt until it's getting red your ok
Try hitting the head of the bolt squarely with a heavy hammer three or four times. Hit it hard. That will cause the bolt to stretch. It should come out quite easily. This method has never failed me yet.
OK, I did not try heating it up again, but did did try the hammer - actually I tried a five pounder yesterday, this time I got out the 12 pound sledge hammer and gave it 4 good whacks & put the 8 inch cast iron pipe on it - the pipe broke right off (see pic) so I had a steel telescoping Lally Column and tried that - it broke free right away - THANKS TO ALL - and tinkerer, thanks for reminding me about the hammer.
Hey was it ok to do the work on the cylinder while it was still hooked up on one end ? I’m waiting for the seal kit for mine I have a 1978 case 780ck it’s the dipper cyl on the backhoe
Kyle; Yes you can. Lay the boom and dipper straight out and resting on the ground. Remove the pin out of the rod eye. Then you can loosen the gland and pull the rod out. You will need to put blocks of wood under the cylinder barrel so that the rod can be pulled straight out. An engine hoist and the machine on a hard surface will make the job immensely easier.
Just adding to what @Tinkerer has said. You will not be able to fully stretch out the dipper, as when you pull the pin on the rod end, you will need to withdraw the rod to clear the dipper & then raise the cylinder & extend the dipper rod all the way out, using blocks of timber to support the cylinder. OR you will need to raise the boom a little after the dipper rod end pin has been removed. If you lower the dipper into a trench it will obviously lower the work height, especially on a 780. OR you could stand on the back of a flatbed.... This is a pic of a 580D reseal to give you an idea. Aussie sideshift model looks a little different ..... & using a certified 4b-390 fanbelt for a lift sling
Ya ok I was kind of thinking of blocking up the cylinder but I can see how it may be a bit of a battle with the height issue I have an old set of steps I guess I could build a platform ! Or like u Salic get lower so I can get some leverage, thanks for replying I’ll try to send pics of what I’m up against thanks for the info !CHEERS MATE
One time I dug a hole in the ground deep enough that the dipper went straight down into it, then I could easily get at the cylinder. After resting the boom assembly in the hole it has to be covered with some plywood or else you will be down the hole.
Thanks for your input much appreciated! I do have the cylinder pin out and I’m going to take the bottom pin off and slide it down to remove the shaft , thanks eh!
If you can secure it very well, make a spud wrench. Burn a hole in 1" stock 18" long big enough to pass an impact socket through & weld together. Then use a sledge hammer on the spud wrench. Likely, a few blows with an 8 LB hammer will start it moving. Most hydraulic shops have a holding fixture & hydraulic cylinder to turn the spud wrench the first 1/12 of a turn. If you can find a hydraulic shop or competent heavy equipment mechanic, they are well worth it.
Well I got the shaft out of the dipper cylinder and got the seal kit am I missing something of did the last owners put something in the seals that was not part of the seal kit ? I’ll try to get some pics on here wow I’m a rocket scientist! ,anyway uh what do u think is the cloth like material that’s hanging off the end of the shaft ? Thanks so much for your input ! All of you !
The piston seal you have in pic 1 is a two piece piston. The 'material' is what those old seals were made of in the 70's. They are also known as chevron seals of Vpackers. If the seal kit you have doesn't look the same, it's likely you have a seal kit for the later models with a single piece piston.