Welded Hydraulic Cylinder That Can't Be Repaired, Cut Open and Resealed

Talking about a POS cylinder !!! That is the worst I have ever seen !!! If I was going to keep whatever piece of equipment that came on I would put a good cylinder on it. How well did that new seal come out with all that welding on that end ??

I was afraid of melting the seal whilst welding. I think i would have pulled the piston out a bit.

Era inservibile ed è rimasto inservibile. Se manca lo stantuffo, come fa a funzionare!!!

Just put a belt around the item on your power roller and hang a weight on light items with a pulley or roller letting the weight hang at the bottom of the belt adding eight easy that way

Its a "positive displacement cylinder"
The rod is the piston, all you have on the end of the rod are wear bushings instead of seals.

All of seals are in the gland nut

The advantages are:
1. You dont have to worry about the cylinder drifting because of an internal (unseen) leak.

2. The pressure fitting can be placed at any point on the cylinder instead of just the bottom of the stroke

One thing I would have done differently. I would have manually extended the ram to its limit before welding the end back on. No reason to expose the ram seal to the welding heat if it could have been avoided.

If you ever run into a situation like that again where you can't see part numbers, call up a company like Dayton Seal and they'll tell you what dimensions to get and then build you up a kit with the right seals for that size.

Yeah that knock is probably the bar inside moving from the force of it spinning 😊

Welding the cap back on with piston retracted? Seal/rubber on end of piston to close to heat?

Wow, thats impressive

Let the Sunshine In...

You did not explain the absence of a seal in the piston.

Awww bit hard on the piston seal welding right beside it, I would have pulled that rod out away from the heat source a bit, but that's me.

you are using dentisit tool

Nice.
So lets see how I do that without a large lathe...and a ultrasonic depth gauge...

Awesomeness

I look at the cly first thing, if it’s welded I tell them what I think and I’m not buying the 💩
Watch out folks or you’ll be shafted by equipment manufacturers

If you pre-twisted your earth clamp cable it might turn ok.

Great Video Josh, As a Pipe welder of more years than I can count. On your welding Motorised Welding Jig, try building a Bail Arm that hinges over the top of the cylinder and clamps down with two bearing wheels to allow easy rotation whilst powering on. Make a fine adjustment screw, so you can push the pipe onto the alignment wheel by eliminating any slip, no matter how light the pipe. I have built many similar devices when I built my Pipe Welding Engineering Workshops. I like your Workplace Methodology. Top job Mate. Cheers from Michael. Australia

That was painful to watch. Not so much an expert demonstration of skill; as a clueless, ham-fisted buffoon demonstrating why noone should emply his services. At least for this type of work. It was hilarious watching trying remove the old seal, and excrusiating watching you do your best to ruin the new one as you fitted it.

First and last of your videos I'll be watching.

I've alway admired machine work, but never had the time to take up one more trade. A pleasure watching you work! Most impressive. I love the challenge of finding ways to make things work that other's say is "impossible". Cheers!

A single acting cylinder does not require a piston seal, some do have a wear sleeve. The giveaway is the single hose. On some off highway dump trucks with two or three stage cylinders one section will be double acting. The dump beds go over center, that section will move the bed back past center and gravity will do the rest.

There are a lot of comments about the type of cylinder this is, and obviously it’s a single acting. This means it is either power out, or lower in, but it doesn’t get powered both directions.
Lots of single acting cylinders start life as standard double acting, meaning they can power in and out, the port on one end can have a breather installed and the other end gets the oil. If it’s double acting it doesn’t matter which end is which, that is determined by the need of the application.
This particular design doesn’t have a piston per se, it works on displacement. As the area of the rod is larger than half the barrel area, when the oil is pressurized, it will naturally force the rod to extend. There is some type of piston/washer/retaining device where the piston goes to prevent the cylinder rod from blowing out of the cylinder. For a common use of this type of cylinder, look at a forklift, lots of the mast cylinders only have rod packing as there isn’t a sealed piston. These cylinders usually have a piston with wear rings, or brass, so as to give lateral support when fully extended. These are single acting displacement cylinders, that’s what he has in this video.
There are mast cylinders that have pistons with piston seals, the draw back to those is once they start to leak the cylinder has to be completely disassembled in order to get to the piston seal. Most mast cylinders don’t have that type piston, hence when it leaks it can be resealed in place, with some TLC and some foul words.
Dump trucks also use single acting cylinders with no piston seals, their cylinders are telescopic, meaning it has multiple sections to the rod so it can tilt the bed high enough to unload (dump) the bed and it’s contents. These are more common than most people think, it’s just the design that changes, but there are lots of these out there.
As far as it being welded together, this is done for one, or more, reasons. First reason is to get people to purchase new as most people don’t realize men like this can still fix them. Secondly, it’s done for safety, some Mfgs don’t want people working on it and use this to prevent them from trying, although this is normally done in more extreme applications where most people SHOULDN’T try to fix it.
I hope this helps explain why there’s no piston seal and why a cylinder would even be made this way. It all comes down to money and safety, but mainly money. Even if it’s not the cheapest to make, it does help control who gets it fixed and who gets to buy new, or in my opinion, who gets screwed!

when rotating light cylinders you might try hanging a preload in the middle of light cylinder ? sandbags on a light rope in middle of cylinder loose so rope does not grab cylinder.

Forget my last comment. I see you use a button as well…never mind

Hydraulic seal removal spoon set makes the removal and replacement of the seals much easier (easier is a relative term with some jobs). They're more robust than the small metal picks for prying. Also help with getting metal retention rings in place on reinstalls where metal retainer rings are used. Cheap and good to have around for hydraulic rebuilds or any o ring job. Good job on the rebuild!

its a displacement cylinder no seals

tack weld a 3/4 " bolt to the end of the eye end put a nut on it put the ground on the nut the nut will screw you will need to adj occasionally

I think they make a swivel magnetic ground for the mig. 😊

Over 50 years ago, I worked as a hydraulic mechanic. As I was taught, this is what is called a "displacement" cylinder. This is a "power in one direction only" cylinder. Oil is pumped in under pressure and the "rod" is displaced. Everyone in America has interacted with one of these cylinders at one time or another.
Many elevators in a building of less than 7 or 8 stories have elevators that are raised by one of these hydraulic cylinders, where a pump lifts the elevator and gravity brings it back down. A hydraulic bottle jack, floor jacks and two and four post car lifts use these type of hydraulic cylinders. Just a little fun info.

Great job

You need a bearing on your ground clamp.

Thats a displacement cylinder, you just shove as much oil as you can in there and out it goes.

one way cylinder and dummy "piston" is wobbling inside :)

i love struggle as long as they are yours

in the Maries, we used 1/8" brass rod and hammered a flatish end so it would help dig out the seals but not bend up liek those picks are.

Love the t-shirt! LOL

I didn't know those seals have part numbers on them. Fingers crossed!

A single acting ram, nothing special about them.
The oil goes in anywhere and pushes the rod out. And then usually gravity takes care of pushing the rod back in.

Change my mind now that I've seen all whole thing you .are the best choice in cutting that end off

Good job again. I always enjoy your videos. Thanks for the video keep on keeping on.

Them harbor freight picks lol

Hit it with your purse

Love DIY's and how anything can be done if you need it to! Thanks for the video

Curious… I didn’t hear you mention finding out what the non piston arrangement was about…??

The spindle bore in that lathe is awesome.

Why not acid etch the end to see where the weld is exactly

Its the paint.

The entire rod is the piston ...

I run a hydraulics manufacturing and repair company that specializes in heavy industrial applications. We refer to this type of cylinder as a mobile or welded type. Mobile/welded cylinders like this are in many cases considered throw away as they tend to be cheaper to buy new than to repair. Something like this could likely be purchased from a Tractor Supply store or something like it for a few hundred dollars. But, sometimes that is not an option. This is known as a volumetric cylinder, as the oil volume and pressure displaces the rod. It is single acting on the extend side, and uses gravity/mass to retract it, or other mechanical action of the equipment it is used for. It does not need a piston seal, or a piston for that matter. The "piston" on this rod is just a stop to keep the rod from being blown out by the oil and pressure at full stroke. It is an odd design though, being completely un-repairable. It really isnt the least expensive way to manufacture this type of cylinder, either. It would cost us more to build this way than to make it repairable. This is just a poor design. Most welded type cylinders have an open tube on the rod end with a threaded on cap that holds the rod seal, the rod wiper, and an oring to seal the outside of the cap to the tube, and it is very inexpensive to build them this way, and much easier to rebuild. This could probably be converted to that style easily, and then it would be rebuildable. When you assembled the cylinder, it took some good hammer hits to get the rod to load through the seals, i would recommend cutting a good load chamfer on the rod, something around 20 degrees, to make this easier to load, and not risk cutting or rolling your new seals. Also, if you dont have part numbers for your seals, you can measure the dimensions of the groove, which any seal company can use to find a seal that will work for you. Lastly, since this is a pressure vessel, be very careful with MIG welding, its very easy to end up with voids and holes that will not hold pressure and allow oil to escape, which can cause a dangerous situation. It can be done correctly with a MIG welder, but care must be taken. I would highly recommend testing this after the repair as well with a small hydraulic unit, utilizing proper PPE, and taking safety precautions. Ive experienced failures during testing where heads blew off, rods blew out the end, oil jets shot out from small holes in welds, etc... We have never had any major injuries from this, we use ballistic shields during testing, but there have been serious injuries over the years in our industry, and even some deaths from failures during testing. Just be smart about it if you do testing, its a pressure vessel, and if it bursts or breaks under pressure, a large amount of stored energy can be released in a bunch of different ways, so be careful. Anyway, you did a nice job repairing that very poorly design and manufactured cylinder, keep up the good work.