Hydraulic cylinder salvage

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Well got a hydraulic job in that called for some extreme measures. The cylinder is rather special and expensive to replace so it called for saving it if possible. That called for some special tools to be built.  So today between about 1000 interruptions I built tools and saved the cylinder.Here's what I started with. Slight oops in the cylinder wall.  First I cleaned and ran a bead across the divot on the outside then ground smooth (didn't get a pic of that). Next was to rough grind the spot down so I didn't tear up my hone trying to get rid of the bump.  Next hone till smooth and hone again with fine grit to get rid of some of the scratches.Finally flap sand till smooth enough not to tear up the new seals. All this required special tools which will be shown in next post.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Here's the tools used to do the job. Near to far is flapper I built today, modified heavy duty die grinder, and hone. I built the flapper shaft so I could smooth the roughness left by the hone out of the bore. It's 1/2" CRR turned to 1/4" on one end and the other drilled 1/4". I then slit the end two ways and sanded till I could get 4 doubled strips of 120 grit slipped on each prong left.  I had to build the frame that allowed me to use the die grinder as a precision removal tool 24" down the cylinder. By adjusting the three arms I adjusted it till the grinding wheel barely missed the cylinder wall when resting on the two arms. With the third arm as a safety to prevent it from bouncing up. I placed the bump on the bottom of the cylinder and worked it across the bump till it stopped grinding.  After that it was on to the hone. First with medium grit stones and then fine stones.  Tomorrow I get to fix the piston. But it'll be easier since it can be done in the lathe. Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Irish.  Thanks for the post I really learned something from you today.  Great job
Reply:Yes, thank you. I also learned something. I also like the guides on the die grinder, good idea.And good job as always.Tim Beeker.
Reply:Originally Posted by richeyIrish.  Thanks for the post I really learned something from you today.  Great job
Reply:Awesome ingenuity and work!Miller Dynasty 200DXMiller Spectrum 250DMiller Millermatic 200Bunch of old blue dinosaurs....
Reply:Great work!I thought I did good when I repaired a rust hole in the bottom of a 4" cylinder.Are you going to test off leaks with compressed air before you put it all back together? Don't ask why I know that's a problem.Be wary of The Numbers: Figures don't lie,. but liars can figure.Welders:2008 Lincoln 140 GMAW&FCAW2012 HF 165 'toy' GTAW&SMAW1970's Cobbled together O/A
Reply:Originally Posted by jontheturboguyAwesome ingenuity and work!
Reply:wow, very clever and great ingenuity.
Reply:Nice work on the shell there irish. If you get a fair amount of cylinder jobs get yourself some of these inner gland seal installers they are slicker then snot. I know of 3 different sizes and they are a real finger and time saver. Post some pics of the ram cleaned up when you get her done.Lincoln 216 powermig/spoolgunLincoln weldpak155Lincoln weldpak100Gianttech cut50HF 80amp inverterEverlast140stHypertherm Powermax30Miller Maxstar150STL
Reply:Originally Posted by golfingweldorwow, very clever and great ingenuity.
Reply:If you can take the piston off it installing the gland from the piston end is really easy.  I have had an instance or two where cast iron pistons are Loctited on the shaft and gall up on the way off (2.5" thread with a 5" piston).  I have since learned to simply grind a large chamfer on the clevis end to facilitate gland installation if it was not there from the factory to begin with.Us dirt bike guys sometime use a seal bullet, like the revers of a piston ring compressor because shock shafts only come in 14mm and 16mm diameter so you don't need a lot of options.
Reply:I love the die grinder on a stick. Thanks for taking the time to show the repair and especially the special tools. Must have been a slow day with only a 1000 interruptions.
Reply:excellent repair irish! i like that collection of tools you used to do it.i.u.o.e. # 15queens, ny and sunny fla
Reply:Originally Posted by forhireI love the die grinder on a stick. Thanks for taking the time to show the repair and especially the special tools. Must have been a slow day with only a 1000 interruptions.
Reply:Originally Posted by 76GMC1500If you can take the piston off it installing the gland from the piston end is really easy.  I have had an instance or two where cast iron pistons are Loctited on the shaft and gall up on the way off (2.5" thread with a 5" piston).  I have since learned to simply grind a large chamfer on the clevis end to facilitate gland installation if it was not there from the factory to begin with.Us dirt bike guys sometime use a seal bullet, like the revers of a piston ring compressor because shock shafts only come in 14mm and 16mm diameter so you don't need a lot of options.
Reply:Always something informative on this forum, thanks for sharing your project!"All of this and some of that's the only way to skin the cat!"
Reply:Originally Posted by BipestuffAlways something informative on this forum, thanks for sharing your project!
Reply:After machining.  I would of had to of built up a LOT more if I wanted it cleaner than that.  Some of the tools used while rebuilding cylinders. After all that the seal kit comes in and it's not the right one. Now have to wait for the right seal. Last edited by irish fixit; 03-07-2014 at 06:40 PM.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Thanks Wayne, sure appreciate you posting.No external leaks in the cylinder, so the damage was caused by a dent I'm guessing.  What was the indicator that caused the owner to bring it in. Lack of performance?Lincoln SA 200Esab Caddy 160Thermal Arc 201TSMiller Dialarc HFI don't like making plans for the day because then the word "premeditated" gets thrown around the courtroom....
Reply:You're welcome.The dent did the damage to the cylinder and the piston. But there was a check valve in the bottom of the piston which came out and did the mangling of the ends of the piston and bottom of the cylinder. But I'm not sure what caused the check valve to come out or when (before or after the dent).  This is one of the strangest cylinders I've ever seen. It's a single acting cylinder but there's no vent on the rod side of the piston. It's not a true ram since it's got a piston and seals either. It's some strange combination of both.  Anyway It's the primary lift cylinder off a forklift. It's what moves the forks. There's two more cylinders that move the mast. This is supposed to be a full free lift forklift (the forks are supposed to move before the mast does allowing use in low height areas). It worked as full free lift when the owner bought it but some time or another it stopped working that way. About 2 years ago they had some forklift mechanic come to fix it. They said it was a valve that feeds the cylinders and changed that. But that didn't fix the problem. It was brought to me to get it to work as full free lift again. At first I thought it could of been the valve (all three cylinders hook to the block). But once I got it off I immediately saw there was no provisions for separating the flow to the cylinders. I then thought they might of put the wrong valve on there. I tried to find info but couldn't get much of anything on it. I did manage to find a parts break down for a newer model though. Looking at it I couldn't really tell a lot but I also couldn't find anything that could of been valving to cause the full free lift. It was puzzling me and a forklift specialist I contacted trying to find the right valve for the machine. The valve that's there is just a flow regulator to prevent it from coming down to fast.  I puzzled over the problem for several days. I couldn't figure out how it was suppose to work. None of the cylinders where leaking and the first pages of the parts break down I found showed them to be rams rather than cylinders.  It finally came to me that if the displacement of the primary cylinder was bigger than the secondary cylinders combined it would cause the forks to lift before the mast. But measuring the rods and calculating the displacement didn't add up that way. Back to the puzzle. Finally I was looking through the parts break down some more when I noticed a note saying see another page. I finally found that page near the end of the 400+ page pdf file. That's when I found a break down showing piston seals and a check valve in the cylinders. I finally decided to pull the primary lift cylinder and see what was inside. That's when I found the problems. The cylinder had been working as a ram rather than a cylinder reducing the displacement to only the size of the rod not the piston. That made it smaller than the other two cylinders causing the forks to lift last instead of first. Since the cylinder is such strange construction it didn't leak (other than the slightest seep around the gland threads) making it much harder to diagnose.  It's still one of the strangest cylinders I've worked on. I guess the check valve is supposed to allow any seepage from the piston seals to drain back into the tank while allowing the air trapped on that side of the cylinder to compress and act as a spring helping the cylinder to come back down.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Is it a Linde forklift? They do things in the most complicated way possible.Millermatic 200Hobart Handler 120Victor O/A & Ramco BandsawLincoln 225 ACSnapOn AD HoodMiller XMT304/22AHypertherm Powermax 1650 G3Lincoln Idealarc DC600 w/Extreme 12 VSMiller Digital Elite "Joker"
Reply:Daewoo G25E-3. I have to say it definitely surprised me when I got into it. Why make a cylinder that complicated when a simple ram would work?Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:So are you saying the forklift has like a 3 stage mast, where the forks lift first, then the 2nd stage then 3rd?And the check valves in the cylinders eliminated the need for external valving.What brand of forklift is it?I don't know that much about hydraulics, what's the difference between a ram and a cylinder?Lincoln SA 200Esab Caddy 160Thermal Arc 201TSMiller Dialarc HFI don't like making plans for the day because then the word "premeditated" gets thrown around the courtroom....
Reply:I this a compressor and guide for the piston glands?  If so where do you get it?  That seems to be the only part that can be tough when I reassemble rams. Originally Posted by FBnormmieNice work on the shell there irish. If you get a fair amount of cylinder jobs get yourself some of these inner gland seal installers they are slicker then snot. I know of 3 different sizes and they are a real finger and time saver. Post some pics of the ram cleaned up when you get her done.Yes this is a three stage mast. In this case the forks lift first and then the two stage masts lift (both stages lift at the same time equal amounts just one stacked on the other).  The check valves really don't make much sense to me on any level really. It's the size of the cylinders that cause the forks to lift first. But because of the check valves and the way the cylinders are made it didn't show any external signs of the damage. Just the malfunction of the forks lifting last instead of first.  By proper definition a ram just has seals on the rod and no piston. There's often a bearing surface of some kind where the piston would be but no seals. Thus the size of the ram is determined by the size of the rod. Example is my big press. It has a ram rather than a cylinder (it's actually a cut down cotton gin ram). In that case the rod (really a hollow pipe sealed on the end) is machined and polished for a seal. Properly known on those old cylinders as a "crimp". It was originally leather. The inside of the so called "cylinder" is rough cast. No real smoothing at all except for near end where the rod comes out. In this case the rod is 8 5/8" diameter so that's the size of the "cylinder" on my press.So for every 1 psi of pressure my pump puts out I get 58.4 lbs of push from the ram. In the case of a cylinder there's a piston with seals on it inside. The inside of the cylinder is smooth and polished for the seals to seal against. Example let's say you have a 4" cylinder with a 1 1/2" rod coming out the end.  In this case if you put fluid in the end opposite the rod you get 12.56lbs of push from 1 psi pressure.  On the other end though it's not that simple. You'll have to subtract the size of the rod from the cross section of the piston.  In this case 1.77 sq inches from the 12.56 or 10.8 pounds pull from the rod for every 1 psi put into the rod end of the cylinder.  What happened to the forklift is that we lost the nearly 75mm diameter of the piston and was only getting the 50mm diameter of the rod for our push.  That means I was only getting 3.04 lbs of push for every 1 psi instead of the instead of the 6.85 lbs of push per 1 psi I was supposed to get.  I'm not sure that didn't confuse me. Hopefully you can follow it. Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Originally Posted by blackbartI this a compressor and guide for the piston glands?  If so where do you get it?  That seems to be the only part that can be tough when I reassemble rams.
Reply:Pretty ingenious way of salvaging a 1 off cylinder.  I thought of an idea that may have reduced some of the work.  What if you hade made a sleeve which just fit inside the bore with a slight taper on it.  Use a rose bud to heat the dented area red hot and then drive the tapered sleeve past the dent to push it back out from the inside?  Would still require the honing and polishing but would have saved the manufacture of the grinding tool.
Reply:Not impossible but I'm not sure it would of saved me that much time and there would of been a chance of heavy scratching and galling while pushing a plug past a red hot spot.  It didn't take me that long to throw the grinding jig together. I don't know exactly since I had to stop and do so many other things while I was doing it.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Nice repair You sir are good!!57 shorthoodmiller 330st aircrafterMM252Hypertherm 10006'x12' Torchmate CNC table"stack it deep and sell it cheap"
Reply:Thanks for sharing, Irish.   Now, were you able to bill for ALL of the time spent?-AaronJet 17.5" Drill Press1942 South Bend 16x84 Lathe1980s Miller 320A / BP --- 2013 Power Mig 2562012 Jet 7x12 Horizontal BandsawVictor O/A Setup
Reply:Thanks guys.  I don't know if I'll get all my time out this particular job yet. Part of the problem is the parts have cost more than they should have. The other factor is that this is a good customer who helps me in other ways so I'm likely to give them a little break on the price. I've not gotten a price on a new cylinder but based on the price for the parts I'm betting I could easily get full price for my time if other factors where not in play.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm