Boom cylinder repair

Tue, 31 Aug 2021 09:35:51 GMT

go to see Welding Machine for Boom cylinder repair

Ive got this old CASE 680 (old leaky) and repaired the bucket cylinder. Now Im working on the Boom cylinder, loosened the gland and cant get the piston outa the tube. The reputable CASEmechanic couldnt get it out either and they tried. They also said theres a liabilty because its been welded before and probably caused it to go out of round causing it to lock up. They gave me suggestions to cut it open, repair the seals and re-weld. They also sent me to a hydrolic repair shop. The estimate was minimum 12 hrs at $85/hr. Not happening.So now I need  please thank you. Im probably gonna get flamed but what do I have to loos xcept possibly my life.   Im going to cut it open a couple inches from the end to get access to piston and then repair, put it together and weld. It was done before and its gonna happen again. I know the danger so I may get someone else to weld if he will even touch it otherwise I will do it.If anyone cares to share xperiance, wisdom, safety issues or sarcasim , please do. My concerns are lining it back up to weld and straightness and concentricity. I will make a timing mark before I cut it to line up after the repair.  I will use a bandsaw to open it. To weld back up, probably TIG to start then cap with 7018. Or should it be the other way. If someone close(Reno, Sacramento) can and has the tools, I would be willing to farm out the work as long as its in my limited budget.Thanks again The cut will be towards the opposite end of the previous welds in the pics. I will also be looking for a used tube in the meen time. Attached Images
Reply:Originally Posted by Insaneride . . .loosened the gland and cant get the piston outa the tube. The reputable CASE mechanic couldnt get it out either and they tried.
Reply:How much time, money and work is it worth to put into an old damaged cylinder? What would one from a scrapped 680 cost at the scrapheap, or even one from another machine that could be adapted to your 680?I've never worked on this type of machinery, I just know from other repairs that there comes a time when you're better of scrapping damaged parts and buying something else. Economy, reliability, liability... Lots of factors to take into account.
Reply:I recently had to bite the bullet on a cab lift cylinder for the other truck.I was considering modifying an off-the-shelf cylinder for the job, but the orginal cylinder is internally fused, and has internal flow control to slow it down when retracting.  Not knowing the ideal speed, and flow rate, I couldn't duplicate the OEM specs with external fusing and restricters.  Bottom line..........I was able to locate the original manufacturer, and order a one-off build.  They located the old engineering drawings for the original production run.  Thank God.  Isn't cheap, but there was no alternative.In your case you could maybe find a cylinder with identical bore/stroke and modify the base and eye end as needed.  Any welded base cylinder can be modified on the base end with little problem (wider, narrower, etc., mounts)The eye end can also be modified to suit.I've done both, and had good luck with it.When welding on the base or eye end, make sure to do it with the cylinder piston fully extended (this keeps the heat away from seals and such).  Welding on the eye end is usually best done with the polished chrome shielded from spatter with a section of pipe etc."Any day above ground is a good day"http://www.farmersamm.com/
Reply850, in stock:http://www.wengers.com/parts/Constru...10-G101256.htmMember, AWSLincoln ProMIG 140Lincoln AC TombstoneCraftsman Lathe 12 x 24 c1935Atlas MFC Horizontal MillCraftsman Commercial Lathe 12 x 36 c1970- - - I'll just keep on keepin' on.
Reply:Thanks for the link Mondo.  I will check with Wengers tomorow. I did find out today, the seal kit is $35 and I cut the tube open. One hour in the bandsaw. The hydrolic people said I should be ok as long as the weld is at the end , no harm to the seal. Thats how they were made.   It will be about 1 inch shorter. If I do go this route, I will prep and groove, then root pass with 6010, grind and cap with 7018.Thanks Alfred for the suggestions and thats kinda the way Im doing it but further inspection as you pointed out is needed.G son, Im having a hard time finding one to match, the dealer is looking for used for me. Mondo shared a link with one but doesnt match.  This is a do or die challenge.farmersamm, I kinda new that this was a job only a farmer could tackle. Farmers can get anything done. Thanks for sharing your wisdom. I would have to modify the cylinder that Mondo pointed out. Now that I have the tube open, I cant get the nut loose. I broke a breaker bar with a 1 7/8 inch socket trying. I cant turn back now. Attached Images
Reply:Heat the nut. They are loctited a little heat goes a long way.Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:Will do farmshop.
Reply:Never say never.I fix that shi+ every day....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Are you gonna clean up that old repair while you are in it this deepMillermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:Zap, you just gave me a  boost of confidence. Thanks.farmshop, I hadnt considered cleaning  up the old repair. It seemed to hold all these years. I will keep it in mind.
Reply:The case 680 tube  bell is known to distort and warp.  I had a 680 and when I had a bad cyl, I would just go and have a new one made with a better gland system.  If hydraulic or air pressure wont force that out it must be severely distorted,  so a new tube at the minimum would be a good idea. Cutting it short like you did shouldn't hurt to much though.  I just ended up with mostly new cylinders after repeated failure. My memory was they weren't too expensive, I had a shop that builds rice equipment make them, they make all there own.  Most hyd shops have tube and rod in stock to easily make any size cylinder, but 12 hrs sounds high.
Reply:One more tip one the case tubes. Leave the connecting tubes off until your gland is tight.  The little bit of air pressure created by tighting it down will force the little o ring and back up ring out enough to have another premature failure.  Also heat to get it off and red loctite to put the piston bolt on. It's really fun when the rod comes out without the piston.
Reply:blackbart, thanks for that info, Im going to get the gland seals in an hour. About $35.  I broke the Bolt free last night using heat and an impact. Had to let the air recover then hit it again before it came off.  Im gonna check with the hydrolic people about building me a tube but the second hydrolic people also wanted 12 hrs. Maybee a new tube wont cost so much.  I did do an inspection  with a HF bore gauge. The idea came out of Alfreds suggestion to inspect. Couldnt see any distortion but that doesnt meen its not distorted. I did find, near  the problem area and previous repair, some caked up oil or whatever it was and a small bit of pitting. Scraped it with a razor and scotch bright. I will show some pics after I rebuild the gland and or weld.  I dont have a tool to instal the seal , but for the last one, I used dental floss to distort the shape into a C shape and then untie when it gets into the race. What do you do? Also, thanks to everyone for your comments and suggestions.
Reply:The old  piston (VEE) seals will be all smeared and almost welded together, thats normal.  You don't need a tool for the top gland seals, just smooth out any sharp edges on the gland and slowly stretch them into place, flat ring last.  Oil everything generously, some people use STP. It can be a challenge to get the piston back in the bore, some times you have to use a comealong or another tractor to push it in enough to start the top gland. Yours should work, I have put back together worse without using new tubes. Remember to leave the hoses loose when you tighten the gland, it doesn't have to be too tight.  Some of the old case cylinders use a small lock screw to keep it from backing back out. Case make a special spanner for the top gland, but if you got it off, even channel locks will get it back on tight enough.  Remember to red loctite the piston bolt and tighten the heck out of it, you don't ever want it to back out, and it will.
Reply:I got the Gland back together. Had to build watchamacallit to be able to spin the tube to grind, bevel, weld, grind, weld the bell back to the tube.I saw the watcha spinner in ZAPS garage first and decided to build my own version out of bed frames but ended up with this (second pic). The last pic is the pitting and reason it wouldnt come out normal. My FCAW welds wernt so bad but they ended up on the bottom of the spinner fixture so I got no welds to this time. Attached Images
Reply:I ran into a new snag, theres a lip to align the bell to the tube and it had a weld in it.  A bigger lathe would be able to cut it out and bevel at the same time but thats not happening.  Then I remembered that I used an OA torch to blast welds out but I have no Oh two. I could get some but I picked up a barely used Hyperthem 380 last week and havnt had a chance to use it till now. My main compressor has about a gallon of water in it so I had to make a dryer/ filter up quick. I had a HF unused filter with an oiler but I dont want oil so I stuck a sack of pink desecant in the oiler then blasted the welds out to get to the lip on the bell. The first pass went ok. Blast, chisel, file then repeat. I was so happy that I tried a second pass but stopped before I really screwed up.  Its ready to grind then weld to the tube.  I still need to hone it out some before the rod will go back in but I can weld it in the meen time.My 16 megapixel Kodak did a better job than me and my bore gauge as far as inspection. Its amazing how the problem area sticks out in the second to last pic.I forgot to show how I got the V seal into the race, last pic. Attached Images
Reply:I live a hour above sac (collins lake) if you need to borrow the spanner.  I am still curious why this much work had to be done to free the piston.  Would hydraulic pressure from the machine not force it out?  Also if this is the boom cylinder, the 680 has 2, a piston failure in one could create lack of pressure in the other.  I have never had to cut any apart like you did, although I have had to fix cracks and rebuild them many times. If you live in N Ca, I have had SWEECO in yuba city build many case cylinders from scratch (using their cyl design) to replace case ones that had warped parts.  Also there are heavy equip wrecking yards in sac.
Reply:blackbart, thanks for the offer on the spanner. The gland actually came off easy but the nut wouldnt slide thru where the pitting and brown stuf is at the gland end. I need to hone that part out or I will have to weld it with the rod and nut installed using Farmersamm's instructions.  The gland will only be on the rod and not bolted to the tube using that method. The CASEmechanics werent willing to hook it up to a dozer to get apart.  The next one I do (sway cylinder?) I will definately make sure its xtended all the way out when I remove it. This 680 is a 1958 or 59 .Last night I TIG'd up a few spots where I over gouged with the plasma. Im ready to do a little grinding and then 6010 root grind flat then cap with 7018.  Do you think a pre heat in the oven at 100* F is necessary ?I thought about farmshop's mentioning the previous repair so I did a little conditioning with a wire wheel and found 2 weld spots that could use a touch up.I will update when I make some real progress. This is becoming the slowest cylinder repair.
Reply:I have just used regular mig for fixing cylinders.  As long as the weld is clean, it should be as strong as 70XX rod in my opinion, so stick to what ever you are best at, Tig would be great if your good at it.  I have never preheated, but I'm sure it wouldn't hurt.  The swing cylinders on those always seem to be bent due to worn out swing tower bushings, but they always still seem to work when reassembled.  I'm not sure on one that old, the last one I had was early 70's. I probably rebuilt every cylinder on it several times!  Just don't over think it, the only hardened parts on those is the chrome lining on the rod and tube, which is probably why it took so long to cut the end off with a band saw. If you have to do any cutting I would stick to abrasives to save your blade teeth. You just have to go postal getting them apart or reassembling them, remember normally they are being moved with 21,000 pounds or so of pressure! (3.14 X R squared of piston X oil PSI)
Reply:If you have to, I wouldn't worry too much about over honing or grinding the ID near the gland end, the piston dosen't spend a lot of time in that area of the tube.  A file will work, it will cut the mild steel, but slide over any chromed areas. Same for cleaning up the rod if you have to weld on it, the file will just slide across the chrome but hit any high spots or spatter. You'll be a hydraulic master in no time!
Reply:apparently that's an old machine. the newer ones (according to latest james bond movie ) have a catwalk mounted to the boom cylinder .miller thunderbolt 250vlincoln square wave tig 175 prolincoln idealarc mig sp250everlast tig 210EXTeverlast power plasma 50chicago electric (hf) 130 tig/90 arcchicago electric 90 amp flux wire3 sets oxy/acet
Reply:the machine in the bond movie was actually a one off machine from cat's custom products devision with the boom and cab swapped sides from the regular production model for better filming.Vantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:I havnt seen the new 007 movie but, while I was at the Case_shop, they had some 580's with special cabs for xplosions and bullet proof windows all around. They came from Iraq to be serviced and sent to Afghan. The windshield (glass only) was 200#.I picked up some new 1/8 Hobart 6010. It didnt seem any better than my 16 year old Lincoln 6010 but I got some piece of mind using it. I have a fairly new box of Lincoln 7018 so Im good there.  I did a root pass 6010 at about 80 amps followed by two hot passes with the same. I bumped the amps to 85 for the 7018 because I think its 5/32? I will have to check today. I had to grind the inside with a stone on a die grinder then finish with a flappy wheel. Im going to fix a couple start marks on the cap weld and call it good.Thanks to everyone on the WeldingWeb, this place has been a huge help and blackbart, I owe you big time. I will keep in mind today about the STP, air and stuf.One more thing of interest, I checked the polished piston with a laser plumb. It was straight as could be visually. I will xpect the sway pistons to be bent but normal. Thanks again bart for that heads up.  Another thing, my 16 Megapixel Kodak worked great as an inspection tool. And the last pic is a piece of angle welded to the tube for a ground. Attached Images
Reply:That welding  don,t look good at all.Not to hurt your feeling, but being honest.Originally Posted by admsweldingThat welding  don,t look good at all.Not to hurt your feeling, but being honest.
Reply:Originally Posted by admsweldingThat welding  don,t look good at all.Not to hurt your feeling, but being honest.
Reply:Originally Posted by InsanerideReally,
Reply:holy magnetic arc blow
Reply:I was supposed to instal the cylinder today, good weather, but was busy with other stuf. I went over the ugly welds with TIG but they aint any prettier but I dont think its gonna leak now.  The cold looking welds were done at 80 amps for 6010 and 85 for the 7018 1/8" rods. Normally I just turn the amps to about 120 for 1/8" and go but I searched this forum for the optimum 1/8" setting and I think 80amps was suggested. Probably should have used 90 amps or so.I cranked the nut wiper to 90 ft/lbs with red loctite. That should be within range? Why does that nut have a shaft thru it?I thought silicone grease would help glide the gland in but, blackbart suggested STP. I dont even know where to get that stuf these days so I used some Groovy Grape oil for Top fuel Alchohol I had left over. It was left over from using in diesel for my kerosene heater but didnt smell like grape. It seemd like the next best thing to STP. I also made a spanner from an old bed frame angle and since I was out of assembly lube, I used lotion on the gland threads. It worked real good with the spanner.The weather is supposed to be bad tomorow and I have something better to do but I will get picks as soon as I make some progress.
Reply:If it was 1/8" 7018, 80 to 85 amps is WAY cold.  I usually run 3/32" in the 90 to 100 amp range.  Maybe a little warmer than that sometimes.  1/8" probably between 120 and 150-160.  I'm really surprised you didn't have a lot of trouble with it sticking running that cold.
Replyid you have a torque spec of any kind for the nut?  I only ask because I havn't worked on a machine that age, but I have rebuilt cylinders on 580 D's thru 580 Super L's, and the big cylinders, we put a lot more than that on the nut.  I had the crowd cylinder on my Super L rebuilt by a hydraulic shop one time because I was too busy to mess with it, and they said they could do it in half a day, and I'm thinking they said that one torqued to close to 800 pounds.  I always just used my 1" impact to put them back together, and never had a problem.  Made sure they were tight, but didn't just keep hammering on them until something broke...
Reply:The torque on the piston gland bolt is basically as tight as you can get it, with red loctite. A cheater bar or a 1" impact would be great. The top gland that the rod slides through can be just channel lock tight or a little more,I have had those back out several turns with no leakage, There is a tiny lock screw on some (Many are missing) to keep the gland nut from backing off. I suggested STP, which is just a thick oil additive, but any oil should work, it's just awkward and tight sometimes.   And others are right 120 or so amps on 7018.  Rule of thumb is rod dia  (.125") = amps (125) as a starting point.
Replyooking back at your first pics, I think the nut with a shaft through it is some sort of a bottom out relief system but not sure.  Usually a bolt holds the piston in place, but I know some cylinders have a safety release valve to keep it from self destructing. Never the less, that nut has to be very tight.
Reply:The reason I went with low amps is, thats what I found suggested on this site from months ago (bad thread?). I normally run 1/8 at 120 amps as I mentioned before but I wanted it to be right so now Im wrong. Its not to late to grind em out and start over but Im not worried at all. I went over it with TIG and Helium + filler at 140 amps less foot pedal position. I think its gonna be ok and plan to instal this afternoon.I didnt have torque specs so;  I set the tool to 140 ft/lbs and started tightning, then it got tight before I reached torq so I backed of the setting till I found it was at 90. With all that red loctite(clean threads w/ 91%alchohol) at 90 lbs, I cant see how its ever gonna come loose. I coulda went tighter but, I would hate it if I broke it and it felt like I was gonna break it. It had 8 or 10 SAE hash marks but with the relief hole in it, I know i could break it.As far as oil, the groovy grape worked fine and smells good. I was wondering if KY would work better but would be embarrassed to go buy some.The lock screw fell in the dirt but the kit came with a new one. Lotion worked as good as assembly lube on the  gland threads as they were sticky.There is an xtra seal, probably for newer models to keep debris out, and isnt shown on my diagram and wont fit on the outer raceway. The raceway had paint and never saw a seal like it so i put it on anyway and will tack it in place after installation with FCAW (weird).Bart, I think your rite about safety relief shaft.  I will forever keep in mind the rule of thumb for amps.Pipeline, I would strain my nuts trying to lift a torque tool capable of 800 ft/lbsAlso, whats a crowd cylinder?blackbart, a Mllion thank you's. BTW, did you ever try your GFI xperiment with ionized or dirty water?  I know I sound crazy when I say water doesnt conduct but distilled or de-ionized acts more like a semiconductor or insulator than a conductor.I will try to get pics up after the instal.Good health and happiness
Reply:Well, I'm probably a little bit more equipped in the "heavy equipment tools" category that a lot of people...  I have a 1" drive Ingersoll Rand impact that's supposed to put out about  1,450 foot pounds.  And if that won't get it, I have a Proto Torque Multiplier, 1/2" input/ 1" output.  It's rated at 3,200 foot pounds output with 173 pounds of input...  The hardest part of getting a piston nut off, or bolt out, is anchoring the polish rod in a way that you won't damage it.The crowd cylinder is the one that pulls the dipper (stick) in or pushes it out.I do wonder about something as far as having to re-pack hydraulic cylinders.  When I was a kid (1970's), it seemed like we were constantly re-packing cylinders especially on the backhoes (we had 7 Case 580 backhoes at one time).  Started with B's, then had C's, D's, E's K's, Super L and now I have a Super M.  The earlier models especially, we packed a LOT of cylinders.  Also had to replace several.  I had the Super L from 1995 to 2009, and only had 3 cylinders ever start leaking on it.  Also, didn't have to replace near as many hoses as on the earlier models... I wonder if this is due to advances in rubber products, better filtration, or what it could be.
Reply:I noticed the newer case backhoes redesigned their threaded bell area which was a source of many leaks. They also  have a lot more steel tubes with short hoses at the flex points.  I don't know if there is any advance in hose design.  I am replacing a lot of backhoe tubes on a 580 super M currently, but thats more because of snagging them on brush and trees.   I know on the case backhoes in the 70's I replaced many with a cylinder design that a local MFG made per my specs (sweeco, in Ca)   I haven't experimented much on the GFI thing.  I learned a little more about what the theory is behind them. I know houses are starting to use a different type of ground fault intterupter in Ca, which is supposed to work on a different principle, but I haven't looked into it's theory yet.    That generic amp setting I gave you is just a starting point.  Thick flux rods (7018,7014 etc) will be more towards the upper end while the thinner (6011,6010) can be less.
Reply:The shaft at the bottom of the rod is a cushion. It slows the flow of oil out of the cylinder when you are close to fully retracted. This keeps the cylinder from slamming to a stop. I doubt if 90 foot/lbs of torque on the nut is anywhere near the factory specs for that cylinder.
Reply:handtpipline, heres a pic of the way I held the polish rod.  Kind of a kluge?I instal'd the RAM today and removed the the 2nd boom RAM. It came apart easy with the come along.I checked for weld repairs on all other cylinders and found some including the dipper that I repacked before the boom1.I heated the bolt (wiper nut) with MAP and hit it with the 3/4 impact for a while , hit it with a ball peen also. Its still stuck.   Seems to be the same cylinder as the last but the bolt doesnt have the relief.Im probably going to have to re-do the first boom  as seeing this second wipers are in better shape. Maybee. Plus I could re torque.My very old 3/4 impact isnt cutting it, should I get a new 3/4 IR or 1 inch chicolm?  I can make a cheater but its gonna break like the the last brand new cheater.So leightrepairs,  what do you suggest for the torque on the bolt with the releif and for the bolt without relief?The boom cylinders are the largest and the rest should be a piece of cake.Thanks everyone for all the response. Attached Images
Reply:I would guess the torque would be in 800 to 1200 ft/lb range, but that is just a guess based on the pictures and the age of the machine. I measure the torque required to remove the nut or bolt when disassembling cylinders or go by the torque specs in Machinist Handbook.
Reply:Your method of holding it should work fine using an impact or cheater.  If you were to use a torque multiplier, you would have to hold the piston end somehow also, as the torque arm on the multiplier would move that end.I would probably disassemble the other cylinder and re-torque it.  They can come apart, and they can do major damage when they do.  I'd also really consider re-doing the weld.  I know you went over it with TIG, but if your root and any other passes were that cold, all you did was pretty up the outside.  This weld is not just responsible for holding the hydraulic pressure, it also is a structural weld in the fact that it has forces constantly pushing or pulling on it.  Not to mention shock load while digging.  I've been around these backhoes LITERALLY my whole life.  40 years.  And I've seen what kinds of forces are put on these parts.  You do NOT want a catastrophic failure of a boom cylinder.  For one thing, you could be sprayed with very hot hydraulic fluid.  The boom is going to uncontrollably fall.  If you're lucky, the bucket will just hit the ground, if not, well... Good Luck