log splitter problem

[Bigjohnsons34]

Hey guys.
Well I changed the pump last year and than the weather changed, got tied up with my kids and sports, and working on the house , So the wood splitter took a long rest
This week I pulled it out to finish up some wood that I had and now it splits the straight grain stuff no problem but the knotty stuff I can not get more than 1200 psi form it
I have a tee with a gauge in line after the valve, I moved the gauge to after the valve deadheading it before the cylinder and still get the same reading
I tried to put it on the hose directly from the pump but can’t start the motor because there is to much pressure
I did notice that when I first start the unit up I can maybe get about 1500 psi but when I run it for a while and the oil gets hot I get closer to 1000psi. Not sure if this means anything
I’m don’t know if it’s a bad pump, I never used it last year or a bad valve or what.
Thanks for any and all advise.
Happy thanksgiving

 

[homemade]

I would look into the valve. You shouldn’t have any pressure on start up.

 

[VirginiaIron]

Your gage should be before the valve. Unless you have detent engaged in retract there shouldn't be any pressure or next to zero.
Relocate gage, try again, and adjust the valves bypass. Happy Thanksgiving

 

[Bigjohnsons34]

Sorry for the misunderstanding
The gauge is mounted on a tee right before the valve
I moved the gauge around to try to get different readings. When I put it directly on the pump that when the motor did not start because there was to much pressure
Thanks

 

[VirginiaIron]

Sorry for the misunderstanding
The gauge is mounted on a tee right before the valve
I moved the gauge around to try to get different readings. When I put it directly on the pump that when the motor did not start because there was to much pressure
Thanks

Did you adjust the valve bypass to increase the pressure necessary to activate the bypass?

 

[NSMaple1]

Sorry for the misunderstanding
The gauge is mounted on a tee right before the valve
I moved the gauge around to try to get different readings. When I put it directly on the pump that when the motor did not start because there was to much pressure
Thanks

Not sure what is going on here. 'Directly on the pump' should be just the same as right before the valve. So you should see the same pressure, and there shouldn't be any difference on how the motor works.

Unless, you mean - you disconnected the hose from the pump outlet & put the gauge where the hose was, on the outlet? Then that would be something you should not do. Unless you had a vid cam rolling and were going for some kind of Youtube explosion video.

 

[Bigjohnsons34]

Today I tried adjusting the bypass on the valve. I believe that I'm adjusting the right. There was a 5/8 nut and when I removed it there was a screw under it.
I could only get 1 full turn clockwise and the pressure got up to 1500 PSI. I tried the screw the other direction and the max pressure was around 900 PSI. So I am assuming that is the right adjustment.
Does that mean that I have a bad valve? and if so should I replace it or rebuild it?
Or is there something else that I should try

Thanks again for all of your help.

 

[VirginiaIron]

Today I tried adjusting the bypass on the valve. I believe that I'm adjusting the right. There was a 5/8 nut and when I removed it there was a screw under it.
I could only get 1 full turn clockwise and the pressure got up to 1500 PSI. I tried the screw the other direction and the max pressure was around 900 PSI. So I am assuming that is the right adjustment.
Does that mean that I have a bad valve? and if so should I replace it or rebuild it?
Or is there something else that I should try

Thanks again for all of your help.

That is the right place. If you had that scenario in extend and retract, I would believe it is the spool. There could be a remote chance the piston is bypassing.

Since you have the gage in the system, and as a temporary test procedure, you could remove the screw and stretch the spring or place a spacer/washer behind the screw temporarily, adjust and check pressures again to see if you can set your system at its rated pressure. Then decide what to do next.

I would replace the spool instead of rebuilding it.

 

[4seasons]

I have not seen what type of pump you have. If it is a 2 stage pump the adjustment should be for the pressure that the high flow low pressure pump disengages and the low flow high pressure does all the work. Your proper hose routing should go from the tank to the pump thru a large low pressure hose. Then a high pressure hose goes to the valve from the pump. This is also the line that you want the gauge on to determine if the pump is working right. Then you should have a larger high pressure hose from the valve to the top or extend port. A pressure gauge on this line will tell you how much pressure is making it thru the valve to apply force to the cylinder to split wood. The hose going from the lower cylinder retract port to the valve can be smaller than the upper extend hose but at least as big as your pump to valve hose. Then the return line should be as large as your upper extend hose and place your filter i the return line. A gauge between the valve and filter will tell you if you have a restriction in the filter. The line between the filter and the tank should have very little pressure and also needs a large hose to limit restrictions.

 

[Bigjohnsons34]

I ordered the valve and finally got around to installing it seeing I’m hone. Same result. I can get the pressure up to around 1300 psi when cold but as it warms up it only goes to about 1000 psi. I turned the adjustment screw in about a 1.5 turns but no difference.

the only thing that has not been changes is the piston. Do I assume that’s the problem of do I have a defect valve or pump?

also there is a “whine“ when there is no load on the piston. Once the wedge hits the wood it stops. I do not remember this before I replaced the valve. The hydraulic oil is good.

thanks in advance.

 

[Wow]

Just reading this. When I worked on airplane hydraulic systems a looong time ago. That system was at 3,000 psi.
Your system may not be that high.
My GUESS is 1500 psi should split wood IF the Actuator Cylinder is big enough. I replaced my Actuator Cylinder last year. I think (without looking) it's 4 inches. May be 3.
The Formula we used is Force is based upon Area X Pressure. I've noticed some splitters have Difference size Actuators. The 22 ton like mine has a smaller cylinder than the 35 ? Ton.
The way a Hydraulic Jack works is the handle activates a small plunger. The Actuator is bigger. It's similar to a small gear turning a bigger gear. I have a piece of Equipment where a 10 tooth Chain Sprocket drives a 50 tooth chain sprocket. That's a 5 to 1 ratio. You'd be amazed how much 1200 psi can do with the big cylinders.
Here is a trick ive used to check my Actuator Cylinder for internal bypass leaking.
Slow your drive engine way down. Just above idle.
Put a piece of wood under the Actuator and pull the selector down driving the wedge into the wood almost to the point where the gas engine starts to bog.
Hold it there a moment.
If the hydraulic cylinder has an internal leak where pressure is bypassing to return the motor should increase speed as the system unloads its self. The ONLY Leaks ive encountered is external shaft seals.
I believe the cylinder seals dried out on one side because the cylinder was stored in the horizontal position. Now I store mine with the actuator vertical.
Also I wipe oil on the shaft by lowering it 4 inches after it's been sitting applying oil to the shaft raising the shaft and do that repeatedly every month or so. In the Military we wiped our cylinder shafts with a soft cloth and Hydraulic oil on the rag. We did that often. Good luck.

 

[homemade]

I ordered the valve and finally got around to installing it seeing I’m hone. Same result. I can get the pressure up to around 1300 psi when cold but as it warms up it only goes to about 1000 psi. I turned the adjustment screw in about a 1.5 turns but no difference.

the only thing that has not been changes is the piston. Do I assume that’s the problem of do I have a defect valve or pump?

also there is a “whine“ when there is no load on the piston. Once the wedge hits the wood it stops. I do not remember this before I replaced the valve. The hydraulic oil is good.

thanks in advance.

The whine from the pump while not splitting could be the pump cavitating.