Log splitter not building pressure

[dave ensign]

MUDD,

I somewhat agree but the exact same problem with two valves gives me pause. I think bad piston seals that are worst on extension and better return.

DAVE

 

[muddstopper]

MUDD,

I somewhat agree but the exact same problem with two valves gives me pause. I think bad piston seals that are worst on extension and better return.

DAVE

Not going to disagree about the cyl, but OP says new cyl and new control valve. The one thing I am sure of is according to the OP the pump is building pressure in one direction. The pump dont care which direction the cyl is moving, it will build the same pressure either way. If the cyl is suspected. All he needs to do is fully extend the cyl remove the hose from the rod end of the cyl and plug it. Then he can try and extend the cyl , see if the oil squirts out of the cyl port. If oil squirts the cyl is bad. If it doesnt squirt, then hook the hose back up, retract the cyl fully and cap off the other hose and try to retract cyl again. If it squirts oil, the cyl is bad. All he needs to test the cyl is one hose cap. If the cyl isnt bypassing oil, that only leaves the control valve, which is supposed to be new also. In the control valve it will most likely be the detent ball not letting the spool make full travel, or the relief is screwed up and letting oil bypass internally, or the valve itself could be cracked.

Now as for bad piston seals being worse on extention than it is on return, not so. The cyl will extend, albeit at a slower speed due to the bypassing oil will serve as a regen. The larger piston area will overcome the the rod side of the cyl due to the rod taking up surface area. Most likely the cyl might retract if oil bypass is minimal, but it will be slower and without power. If you remove the piston completely the cyl will slam out under pressure and not retract at all no matter how much pressure.

 

[ctf58]

Hi guys,
Hydraulic Mechanic says he is 99% sure it is a bad seal in the cylinder. Oil is coming out on the return side of valve when it is fully extended at around 500psi. Now I'm having an issue finding a kit to replace the seals.

 

[Old-Feller]

Hello to the OP, After looking at your lines on your valve, You have the return line back to the tank plumbed to the high pressure side of the valve, And the low pressure return line is plumbed to the high pressure side. You are going to have to make a mount for your valve so you can plumb this right. I will include pics of the splitter I built and after I looked closely at your plumbing, I am 100% sure this is your problem and this explains why you are getting pressure into your hyd reservoir.

 

[Old-Feller]

More pics, You can eliminate one hose by mounting your valve to the cylinder with a schedule 80 pipe nipple 3 inches long, It would go to the return port on the cylinder, Then use one of your remaining lines for the push side of the ram, But you definitely have the pressure and return reversed.

 

[Old-Feller]

Actually, I think I am wrong after looking at your plumbing again. It looks to me like it is plumbed just like mine, However there are different valve setups with reverse port setups like this link to this one. https://www.ebay.com/itm/284008576842?hash=item42203af74a:g:JH0AAOSwLSBfW8o3

Is the ports on the valve marked?

this valve is the opposite of the valve in the link

 

[dave ensign]

Like I said from the start, Just Saying.

 

[ctf58]

Thanks,
Mechanic said plumbing was correct other than he recommended moving the filter from the intake to the return side of the system so that as it gets contaminated it will not restrict intake to pump

 

[muddstopper]

Hi guys,
Hydraulic Mechanic says he is 99% sure it is a bad seal in the cylinder. Oil is coming out on the return side of valve when it is fully extended at around 500psi. Now I'm having an issue finding a kit to replace the seals.

He is probably correct, but If I am understanding you correctly, he operated the cyl and removed the return line hose to check for oil flow. Not the correct way to check for a bad cyl. The oil returns to tank when it flows over the relief valve also. His check could be showing a bad relief valve. I explained in my other post how to check the cyl. That method takes the relief out of the equation. I would check as I suggested before tearing down the cyl to replace piston rings, it only takes one hose cap to do the cyl test and will let you know for sure the cyl is the problem. I know you said the cyl was new in your first post but new now days doesnt mean anything. I bought a new cyl from northerntool a few years ago. I wanted bigger ports so I took cyl apart to drill out the ports. I found the inside of the new, never used cyl to be full of what looked like drill shavings. If I had used the cyl without tearing it down first those metal shaving would have made a mess of my hydraulic system.

 

[pdqdl]

He is probably correct, but If I am understanding you correctly, he operated the cyl and removed the return line hose to check for oil flow. Not the correct way to check for a bad cyl. The oil returns to tank when it flows over the relief valve also. His check could be showing a bad relief valve. I explained in my other post how to check the cyl. That method takes the relief out of the equation. I would check as I suggested before tearing down the cyl to replace piston rings, it only takes one hose cap to do the cyl test and will let you know for sure the cyl is the problem. I know you said the cyl was new in your first post but new now days doesnt mean anything. I bought a new cyl from northerntool a few years ago. I wanted bigger ports so I took cyl apart to drill out the ports. I found the inside of the new, never used cyl to be full of what looked like drill shavings. If I had used the cyl without tearing it down first those metal shaving would have made a mess of my hydraulic system.

Yes, but it's a heck of a lot easier to detach the "retract" hose from the valve and hold it over the tank. Extend cylinder. It will discharge oil until the cylinder reaches it's limit or is otherwise stopped, and then the oil will stop flowing. Providing the cylinder isn't leaking, of course. If it is leaking, then it will continue to discharge oil.

There is also a side benefit to this plan. The open port on the valve is somewhat open to the return line system pressure, but only after it has passed the pressure valve. If you are getting pressurized oil out of the open port on the valve, that's a sure sign that something is amiss somewhere besides the cylinder.

 

[ctf58]

Okay where is the relief valve? Are you talking about something on the control valve or on the pump? I have put a brand new control valve and got the exact same results. 500-750psi forward and 2000psi going backwards.
Or are you talking about on the pump? I have adjusted the slotted screw under the cap on the intake side of the pump so that it bogs but doesn't stall. From what il seeing online there is another ball on spring type valve on the output side of the pump but I have not touched it because I do not know what it does.

 

[triptester]

The pressure readings on the gauge should be the same regardless of direction. It appears that the problem is with the cylinder.

 

[muddstopper]

Yes, but it's a heck of a lot easier to detach the "retract" hose from the valve and hold it over the tank. Extend cylinder. It will discharge oil until the cylinder reaches it's limit or is otherwise stopped, and then the oil will stop flowing. Providing the cylinder isn't leaking, of course. If it is leaking, then it will continue to discharge oil.

There is also a side benefit to this plan. The open port on the valve is somewhat open to the return line system pressure, but only after it has passed the pressure valve. If you are getting pressurized oil out of the open port on the valve, that's a sure sign that something is amiss somewhere besides the cylinder.

You can test the cyl several ways, provided you keep plenty of staydry on hand to clean up the mess

 

[dave ensign]

MUDD,

WE COULD BE FRIENDS!

dave

 

[pdqdl]

Okay where is the relief valve? Are you talking about something on the control valve or on the pump? I have put a brand new control valve and got the exact same results. 500-750psi forward and 2000psi going backwards.
Or are you talking about on the pump? I have adjusted the slotted screw under the cap on the intake side of the pump so that it bogs but doesn't stall. From what il seeing online there is another ball on spring type valve on the output side of the pump but I have not touched it because I do not know what it does.

The pressure relief valve is probably built into that cone shaped protrusion on the new valve you installed. Sometimes they are built into a separate area of the valve. If you saved your original documents, it should at least be mentioned how to adjust the pressure relief valves.
Since your engine keeps running when it is stalled on retract, I am assuming that it is set about right, and shouldn't be the problem. How 'bout you tell us what model of valve you bought, and we can find out more info on that?

I continue to think that it isn't the cylinder, however. No amount of "bad seals" will cause the tank to overflow. I've bought far more hydraulic cylinders over the years that the average joe with a log splitter, and I've never had one that failed when new. I think that is the last place you should be looking.

I want to see proof that the hydraulic motor is being spun in the correct direction. I would like to see the details on the casting of the hydraulic valve to make sure it isn't being fed oil from the wrong side. And I want to see something that assures me that the oil is being picked up from the bottom of the tank (or close).

I believe that something is letting air into the system. You said the high pressure lines were loose, yet didn't leak. In my opinion, that cannot happen.

And... I have not heard any reports as to whether there was a check valve located anywhere on the system. One little check valve in the wrong spot can cause troubles, as can a pressure relief valve.

 

[Old-Feller]

That cone shaped thing is the cover for the return detent adjusment. Which is usually somewhere between 500 to 800 from the factory.

 

[muddstopper]

Okay where is the relief valve? Are you talking about something on the control valve or on the pump? I have put a brand new control valve and got the exact same results. 500-750psi forward and 2000psi going backwards.
Or are you talking about on the pump? I have adjusted the slotted screw under the cap on the intake side of the pump so that it bogs but doesn't stall. From what il seeing online there is another ball on spring type valve on the output side of the pump but I have not touched it because I do not know what it does.

I have said this already, but the pump dont care which direction the cyl is going, it will put out the same amount of pressure in either direction. I would stop messing with the pump, it is not your problem. I believe you said you had a energy control valve, I think pressure is preset on those valves, but never fooled with one so I cant be sure. With all new parts, is it possible you have the hoses connected wrong.

 

[CJ1]

cj

 

[ctf58]

Air leak was taken care of. A line was not tightened up. I used a heat sensor and when trying to split a peice of wood for a prolonged time a hot spot showed up on the cylinder. It went up about 20° higher than the rest of the cylinder and was roughly the same distance from the end of cylinder compared to the wood I was trying to split.

 

[ctf58]

Here is the new valve I replaced the energy with. I is connected the same was the Energy was. My plumbing is the same as the diagram, except that my filter is on the outlet of the tank. No check valve. It would be virtually impossible to plumb it differently because the hose to the "A" port would not reach the "B" port. Also the "A" port is a small nipple straight into the ram end of the cylinder.

I'm sure I could change the seals in the cylinder but I cannot find a seal kit for that model cylinder. The mechanic is quoting me $150 to do the job. I could buy a new one for $190..
Thanks again guys.