hydraulic failure in two way splitter

[chuckwood]

I have a splitter that is designed differently from most. The splitting wedge is welded onto the cylinder, and the piston is stationary, with the moving cylinder doing the splitting. It's had three years of heavy use. Earlier this year it developed a problem in that it could only split in one direction instead of two. In one direction, it had only enough power to move the cylinder back into splitting position but not enough power to actually split anything. At first I though maybe a seal had gone bad in the cylinder and was allowing fluid to bypass in the other direction leading to loss of power. I figured I'd keep using it as a one way splitter until it broke down completely, which it did today. Moving the valve to retract the cylinder resulted in the cylinder suddenly moving in the opposite direction than it should have. So now it's fully extended and will not retract. I'm assuming now that it's the control valve that has malfunctioned. So should my first step be to remove the control valve and take it apart to see what's wrong?

 

[Jakers]

its still the seal. more piston face on the extend side. it could happen at the valve side too but usually valves are tight tolerance and dont flow much fluid in an internal leaking situation

 

[chuckwood]

its still the seal. more piston face on the extend side. it could happen at the valve side too but usually valves are tight tolerance and dont flow much fluid in an internal leaking situation

Well, then I think I know what caused the failure if it's piston seals. Splinters and small pieces of wood are packed into a recessed area on the end where the rod slides in and out of the cylinder. I try to keep debris out of it but it's almost impossible to get in there and get it all out. To really clean it I'd have to remove the entire cylinder assembly just to get to it. So when I get this fixed, I'll have to weld up some sort of removable guard on the end of the cylinder to keep wood splinters from getting in there. Splinters have probably punctured the seals. But I've not noticed any hydraulic fluid leaking out......

 

[JeffHK454]

Wedge is attached to the tube and the rod is mounted solid to splitter chassis...tube moves..correct?

But like what was allready said above, its got bad piston seals and the non-rod side wins the surface area battle.

 

[chuckwood]

Wedge is attached to the tube and the rod is mounted solid to splitter chassis...tube moves..correct?

But like what was allready said above, its got bad piston seals and the non-rod side wins the surface area battle.

Yes, the rod is mounted solid to the chassis. Well, I think on this one I'll just remove the hydraulic cylinder assembly and take it to a shop. Maybe a $100.00 repair?

 

[ChoppyChoppy]

Yes, the rod is mounted solid to the chassis. Well, I think on this one I'll just remove the hydraulic cylinder assembly and take it to a shop. Maybe a $100.00 repair?

$200-300 around here.

 

[chuckwood]

$200-300 around here.

Well, I've been spending some time on you tube watching hydraulic cylinder repair videos. It seems to be a fairly simple procedure to rebuild them. However, I'm wondering if finding the parts to do it could be an issue for me. It's a Harbor Freight splitter. I like the machine because it's fast in that it splits both ways, and there's not as much time spent in waiting for the wedge to retract fully for the next split.

 

[hanniedog]

Can you post a photo of the splitter. Want to see what you have.

 

[dave_dj1]

I just rebuilt a 4" didier the other day and it cost me $16.20 and some time, I did know how to get the cylinder apart though with the help of youtube.
To be fair, I didn't put anything new on the piston end, just rebuilt the end piece, O-ring, backer, wiper and double lip seal. I bought them at a hydraulic shop. Great people.

 

[JeffHK454]

Well, I've been spending some time on you tube watching hydraulic cylinder repair videos. It seems to be a fairly simple procedure to rebuild them. However, I'm wondering if finding the parts to do it could be an issue for me. It's a Harbor Freight splitter. I like the machine because it's fast in that it splits both ways, and there's not as much time spent in waiting for the wedge to retract fully for the next split.

Have you looked to see if it's rebuildable..some low cost rams don't have removable glands or end caps. If you can dissassemble it then rebuilding it is possible if you take care to not destroy the seals and take them to the local seal/hydraulic shop. A set of cheap dial calipers and a couple measurments along with the old seals and any good counter guy can spec. in all the replacement parts.

If you start into the project check the condition of the tube bore & ram chrome ... and replace the gland seals and wiper while you're in there.

 

[Jakers]

To the op, the seal on the piston is internal and the leakage is internal. The seal on the end that you described as getting beat up by debris is a dust seal. There's a pressure seal under that to hold back fluid pressure inside. If that seal leaked you'd have an oily mess coming out around the rod. The seal that's bad is on the piston attached to the inside end of the rod. Good luck with rebuilding it, most harbor freight stuff is non serviceable.

 

[ChoppyChoppy]

Can cut the cap off the tube and reweld if it's just welded on.

 

[chuckwood]

To the op, the seal on the piston is internal and the leakage is internal. The seal on the end that you described as getting beat up by debris is a dust seal. There's a pressure seal under that to hold back fluid pressure inside. If that seal leaked you'd have an oily mess coming out around the rod. The seal that's bad is on the piston attached to the inside end of the rod. Good luck with rebuilding it, most harbor freight stuff is non serviceable.

Well, this is getting interesting. I appreciate all the feedback from y'all, and I'm replying here to more than one post. I can't really complain too much about my splitter, I got it on sale and it's basically already paid for itself. I've used it pretty hard. However, if it turns out that the cylinder assembly can't be rebuilt very easily or at all, I won't be purchasing another HF model. There is at least one more 2 way splitter out there on the market with a very similar design to the HF splitter, but I think that one is made in the USA instead of China. There is no oily mess coming out around the rod, I'm not losing any hydraulic fluid. However, there is no removable cap on that end where the rod goes in. But on the opposite end, there is a cap. It is held in place by a bolt that can be removed with a big allen wrench. I'm wondering now if I can access the piston on the opposite end by removing that cap. I guess I'll be finding out soon when I remove the cylinder assembly sometime this week. I'm the type that enjoys tinkering and welding, I've got a small shop so maybe there is a way I can get this thing running again. The predator engine on this splitter has performed flawlessly, always starting on the first or second pull. I don't look forward to junking this machine. Here's some pics of both ends of the cylinder.......

 

[kevin j]

so if this is a moving cylinder body, does the hydraulic connection port through internal drillings in the rod? That's often done but it's quite expensive to make.

on the rod end of the cylinder, it looks like there's a wire snap ring outboard of the seal holding it together. if you can push the rod gland assembly into the cylinder then that wire snap ring comes out and then the gland assembly comes out the rod end. the wire snap ring may be held in kind of a groove and will not come out until you push the rod gland assembly in, or the snap ring my come out just as it sits. It depends on the cylinder design

The allen bolt on the closed-end might be holding something inside I really don't know but it does not look like the closed-end comes apart

almost always the closed-end is welded because of stress issues, and because the rod end has to be removable for construction purposes and just how they make the cylinder so there is no point in having the closed and removable

 

[Hinerman]

Well, this is getting interesting. I appreciate all the feedback from y'all, and I'm replying here to more than one post. I can't really complain too much about my splitter, I got it on sale and it's basically already paid for itself. I've used it pretty hard. However, if it turns out that the cylinder assembly can't be rebuilt very easily or at all, I won't be purchasing another HF model. There is at least one more 2 way splitter out there on the market with a very similar design to the HF splitter, but I think that one is made in the USA instead of China. There is no oily mess coming out around the rod, I'm not losing any hydraulic fluid. However, there is no removable cap on that end where the rod goes in. But on the opposite end, there is a cap. It is held in place by a bolt that can be removed with a big allen wrench. I'm wondering now if I can access the piston on the opposite end by removing that cap. I guess I'll be finding out soon when I remove the cylinder assembly sometime this week. I'm the type that enjoys tinkering and welding, I've got a small shop so maybe there is a way I can get this thing running again. The predator engine on this splitter has performed flawlessly, always starting on the first or second pull. I don't look forward to junking this machine. Here's some pics of both ends of the cylinder.......

View attachment 594798 View attachment 594799

IF you get it apart, take the rod and all seals and gaskets to a cylinder/gasket shop. They will measure and match all the seals/gaskets perfectly. If they don't have them in stock, they will order them for you and will probably be better quality than what the cylinder came with. I ordered an extra set for mine just in case.

 

[chuckwood]

so if this is a moving cylinder body, does the hydraulic connection port through internal drillings in the rod? That's often done but it's quite expensive to make.

on the rod end of the cylinder, it looks like there's a wire snap ring outboard of the seal holding it together. if you can push the rod gland assembly into the cylinder then that wire snap ring comes out and then the gland assembly comes out the rod end. the wire snap ring may be held in kind of a groove and will not come out until you push the rod gland assembly in, or the snap ring my come out just as it sits. It depends on the cylinder design

The allen bolt on the closed-end might be holding something inside I really don't know but it does not look like the closed-end comes apart

almost always the closed-end is welded because of stress issues, and because the rod end has to be removable for construction purposes and just how they make the cylinder so there is no point in having the closed and removable

Yes, the hydraulic connection ports through internally in the rod. I can't see any removable parts or rings on the rod end of the cylinder, it's all welded in. I'm still unable to figure out how to get the rod and piston out of the cylinder without taking a plasma cutter or cutting wheel to the rod end of the cylinder, and that procedure could ruin the end of the rod if something doesn't go right. It could be that the end of the rod that has the hydraulic lines attached to it was welded on after everything else was assembled. That would require cutting off the end of the rod to disassemble it all, and I'm not sure I have the welding skills to weld something like that back up. It would have to be done very precisely and with the right welding rods and equipment.

 

[NSMaple1]

First pic in post 13 - do i see a seam, where it looks like something might unscrew? Right in front of the wedge weld blob?

 

[chuckwood]

First pic in post 13 - do i see a seam, where it looks like something might unscrew? Right in front of the wedge weld blob?

I see what you are noticing, but it's not a seam. The piece on the end with the big round opening for the rod is welded on. I'm thinking of cutting that end piece off with a big skillsaw with a metal cutting blade on it. As long as I set the depth on the blade properly I could cut the very end of the cylinder off without harming the rod.

 

[JeffHK454]

Thing is , once you roughly cut the endcap off you'll have to re-machine that tube / end cap joint you've created so they're nice and perpendicular to the ram stroke. If you get the cap fitted you'll need to be a good welder that can lay down leak-free and pull-free welds all while not overheating the area with the new seals you've just put in.

If that cap cocks it will drag or bind the rod and screw up the chrome plating ..not good.

Also, pin hole leaks are very dangerous in hydraulic systems , even a simple splitter can see 4,000-5,000 PSI spikes that happen faster than a PRV can dump back to tank..high pressure oil can be deadly.

Don't be afraid to try just be cautious.

 

[NSMaple1]

No way would I try a weld like that - we have a couple of welders here, but I'm not a pro welder.

I hired welding on my water tanks done, and they don't see more than 20 psi. 3-4000 psi? Not a chance.