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08-11-2011, 09:12 AM #1
Hydraulic Cylinder End Cap Removal.
I need to put new seals in two cylinders that about 8" in diameter. They have external threads on the cylinders and internal threads on the end caps. The end caps have nothing to grasp in order to turn. The only solution I can conjure up is to cobble up a really big strap wrench using an old 2" nylon cargo strap, but I knew that a lot of you would have run up agaisnt this before. How did you solve it?
08-11-2011, 09:51 AM #2
IME You'll be lucky to get away with a strap wrench, thoos sonsof bitches can be TIGHT!,....... if it's got to be done without hydraulic power then it's get out the chain pipe wrenches (chain tongs) time.
FYI - don't shoot me over the brand, it's the firt pic I found
Chain Pipe Wrench,manufacturer,exporter,supplier,online shop,supply,india,uk,usa,us,canada
jackal liked this post
08-11-2011, 10:05 AM #3
I've sure been there. If you're not averse to welding a big flat chunk of plate on it with a handle stuck to it, you'll find it won't distort the cap into an egg like a wrench will. I usually put 4 tacks at 90º. Then cut the welds and carefully grind smooth when your done. To hold the other end, I sometimes slide it under my forklift with a bar through the eye end.
08-11-2011, 11:42 AM #4
Hydraulic Cylinders= Methods you have never imagined possible.
Some ideas to disassemble are mean, cruel, sadistic & downright violent.
oldbikerdude37 liked this post
08-11-2011, 11:51 AM #5
SJM, you got one of the easier types. Whale on the side of the threaded ring with a 2 pound hammer all the way around and a few good licks on the end of the ring. I have seen cyls that resisted big wrenches give up to that. All the impacts will loosen dirt and rust and take off some of endwise tension. Welding bars or "wrenches" to end cap will give you plenty to grip.
08-11-2011, 12:11 PM #6
Usually start with about a 10ft minimum length of bar...
As others have said, 8" round cylinders have the potential to be super tight,
And sometimes they are not so tight...
I would also carefully look for a grub screw hidden away under paint or dirt that stops the end cap from coming loose.... Some have them, some don't...
08-11-2011, 12:55 PM #7
Oh man, this is making me look forward to going to work tommorow
As I left it today, I had it cradled in a pc. of 6" channel, with the body secured by a couple of Vise Grip chain clamps. The channel is tacked to one of our 4' x 20' welding tables. I had thought that a strap wrench with a 2" strap and about a 5' handle would be enough. Sounds like I'm going bear hunting with a switch.
I would not have thought that a big strap wrench would have egg shaped this cap. I would think that would take a lot of torque.
My other problem is that I have an ultra conservative boss. The minute I start talking about tacking a plate onto the end cap, we'll be the proud new parents of a litter of kittens.
08-11-2011, 03:10 PM #8
08-11-2011, 06:34 PM #9
08-12-2011, 03:19 AM #10
Here heat is your friend. Heat the cap & use the chain wrench. When you burn the paint off it should be hot enuf. Use a rosebud on your OA kit
08-12-2011, 10:40 AM #11
08-12-2011, 01:27 PM #12
#1 the hammer, give the od of the nut a good swat all around but dont go crazy, but spent some time to bust the rust and dirt away. then grab the chain wrenches. you might even weld on a tab to beat on with a hammer.
#2 the torch get one place on one side hot and go to the chain wrenches.
now if that fails..
#3 the torch and use oxygen and blow the nut right off in seconds. then you have to make the nut but if their crap was not bad you would not be messing with it anway.
08-12-2011, 09:51 PM #13
Heat can be you're friend, or worst enemy! I've seen where it's been heated cherry red throughout the area. Including the internal. Then you grab your 12 foot pipe wrench and start tugging. Presto! Galled threads! A little ''quick'' heat by a rosebud is the best way. It takes just a few hundred degrees to release the Loctite. If you have a thin outer end cap and heat it to much, it will distort with a chain or pipe wrench. The rocker shoe on a chain wrench tends to push in at that point. A 2 pound hammer is always a good first try. Or a burp gun, but that's ear shattering. Generally, I don't see Loctite used, except for the piston/rod assy.
08-13-2011, 02:50 AM #14
Yes, a torch in the right hands can do wonders.
I have had to machine nuts off of cylinders because someone melted the o-rings & Teflon rings into a big plastic mass that ran into the threads, etc.
Right now my main customer wants me to make them a clamp wrench similar to a steady rest.
This is so they can put it on their tear down rack when tearing down telescopic cylinders.
The outer can is clamped in v-block chain vises, they will use this "clamp rest" to hold the other stages while they loosen the nuts.
I have found out with hydraulics, anything is possible.
Lately we have run into metric rods with American Standard threads.
Some cylinder nuts are best taken off carefully with a cut-off wheel and a grinder.
Each cylinder has its own methods, and needs.