Log splitter not building pressure
- Thread starter ctf58
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dave ensign
Trapshooter
What is amazing is that you could get pressure on the return stroke.
ctf58
ArboristSite Lurker
Yeah I'm not understanding that either
Little picks like these help a lot:
https://www.amazon.com/s?k=seal+pick&ref=nb_sb_ss_ts-doa-p_1_9
Harbor Freight has some similar. I'm sure that Snap-On & Mac have some too, but they won't talk to me.
https://www.amazon.com/s?k=seal+pick&ref=nb_sb_ss_ts-doa-p_1_9
Harbor Freight has some similar. I'm sure that Snap-On & Mac have some too, but they won't talk to me.
I would wipe dry the inside of cylinder and look for any flaws with the wall.
Go to the hydraulic guy and buy an o-ring from him or go to a large tractor dealer, one that sells implements. They should have a suitable o-ring. Take both the cylinder and ram with you.
Go to the hydraulic guy and buy an o-ring from him or go to a large tractor dealer, one that sells implements. They should have a suitable o-ring. Take both the cylinder and ram with you.
https://www.baileyhydraulics.com/products, pretty much get any cyl part here that you need.
Old-Feller
Pretty Fart Smeller
"Sure. You knew what you were doing. It's not quite the same instructions for less experienced people.
I pretty much know what I am doing, too, but I still find that separating or actuating hydraulic cylinders with air pressure is a bit iffy. Chain hoist or other rigid pulling device? Not so unpredictable."
I agree with that.
I pretty much know what I am doing, too, but I still find that separating or actuating hydraulic cylinders with air pressure is a bit iffy. Chain hoist or other rigid pulling device? Not so unpredictable."
I agree with that.
ctf58
ArboristSite Lurker
Took piston to hydraulic shop about 45 minutes away. He put new seals on piston and gave me 2 O rings for the end caps. NO CHARGE!
Cylinder looked good with a super bright LED shining down it.
Reassembled the whole thing, bled the air and...
Cylinder looked good with a super bright LED shining down it.
Reassembled the whole thing, bled the air and...
ctf58
ArboristSite Lurker
Well, you have basically a brand new splitter. Enjoy the many years of service ahead.
We still have not answered why there would be oil blowing out the tank vent.
You can be assured that the bad seal in the cylinder wouldn't cause that problem.
Over fill the tank with hydraulic oil while the cylinder was extended could do that, though.
You can be assured that the bad seal in the cylinder wouldn't cause that problem.
Over fill the tank with hydraulic oil while the cylinder was extended could do that, though.
ctf58
ArboristSite Lurker
I posted way back It was a loose fitting.
dave ensign
Trapshooter
First things first, the cylinder always has the same amount of fluid in it. If we add some air from the intake side than that air must be sent into the fluid tank to purge the air. That is when the excess comes out the vent. Your correct, not a bad seal but air being sucked into the system. Nothing to do with a cylinder seal. If the OP could have reversed the lines as I suggested day one we would have known the issue was the cylinder but he could not do that. The problem has been fixed, NOT A PUMP, NOT A MOTOR HP, NOT A PUMP DIRECTION, NOT A RELIEF VALVE, NOT A DETENT, NOT A VALVE. It was a bad piston seal. Nothing else. GLAD WE COULD ALL HELP.
I hope you can all help me with my floor jack when I get to the point I have a question!!!!!
Ummmm.... No, you are mistaken. Just think about that a little bit harder.
Almost all cylinders hold more oil extended, and less oil when retracted.
The ram goes in and out of the cylinder, displacing fluid as it comes in. The only exception to that rule would be a very unusual type of cylinder that has a rod on each end of a cylinder, such that one pushes while the other pulls. I have never seen one, but I'm sure it could be built.
Not only does the tank over flow during some unusual circumstances, it is actually pretty damned common with certain applications. I can't tell you how many times I have seen one of my dump truck reservoirs blow oil all over the place when the bed is raised to add oil, the mechanic fills up the reservoir, and then the excess oil pours all over the ground when the bed comes down.
Certain hydraulic systems are designed with different limits imposed on them. A dump truck has a very low capacity reservoir, as it needs little cooling on account of it's infrequent use. A log splitter has only one cylinder, but it sees lots of action. The reservoir must be built big enough to act as a cooling radiator for the system. Still... If it is filled to the top when extended, it will blow oil out the top when retracted. Not just occasionally, or rarely: ALWAYS!
dave ensign
Trapshooter
Sorry, but BS, what goes in comes out. But if you add fluid, (top off the tank) then you could get some displacement problems. But if some air is brought into the system because of a suction problem then it must go someplace. Cylinders are ALWAYS FULL, BOTH ENDS. When a dump truck puts fluid in the one or two cylinders to raise the box, the fluid in the other end of the cylinder goes back to the tank, when the box drops, the fluid travles
back to tank but also back to the other side off the cylinder.
back to tank but also back to the other side off the cylinder.
When the ram is extended, there is more area thus more fluid. When the ram is retracted, you now have the ram to figure in the equation. Hence less fluid. Think about it.
The reason he could not swap hoses is because the control valve is hard piped to the cylinder. Looking back at it, it now makes sense. It just would have taken a bit more work than he wanted to do. I guess.
dave ensign
Trapshooter
Sorry, eat my shorts. You are correct. In a single hose system there is no fluid in the cylinder upon return. There fore the top end of the cylinder is empty upon return. More fluid in the tank.
The rod displaces fluid, even on a double acting cylinder. When the ram is extended, the rod is no longer inside the cylinder, so the cylinder now holds more oil and less steel. Reverse that condition for retracted. Excess oil upon retraction returns to the tank. No room left in the tank? Out the top it goes!
There is a mathematical corollary here to the power a hydraulic cylinder can exert in each direction, too. A cylinder pushes much harder than it retracts, because the surface area of the piston is larger when extending, and smaller on retraction because the area of the rod is subtracted from the area of the piston.
Similarly, given an identical flow of hydraulic fluid, cylinders retract faster than they extend, because it takes less fluid to fill the side holding the rod.
Besides, both my dump trucks have double acting cylinders. So... Let's not talk about eating any shorts.
There is a mathematical corollary here to the power a hydraulic cylinder can exert in each direction, too. A cylinder pushes much harder than it retracts, because the surface area of the piston is larger when extending, and smaller on retraction because the area of the rod is subtracted from the area of the piston.
Similarly, given an identical flow of hydraulic fluid, cylinders retract faster than they extend, because it takes less fluid to fill the side holding the rod.
Besides, both my dump trucks have double acting cylinders. So... Let's not talk about eating any shorts.
ctf58
ArboristSite Lurker
If a moderator wants to close this thread it is fine with me. Thanks again to everyone who tried to help me out.
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