Alright, I ran into an issue today with my splitter. I could only build pressure up to about 700 psi while splitting some tough locust wood. I have my relief set at 1500psi and if I cycle the cylinder to the end, my gauge will climb right up to 1500psi, however on a piece of wood it just tops out at about 700. I believe the pump is not going into second stage. Howcan I determine the exact issue, whether it be a pump, cylinder, or valve problem? All 3 parts are likely 20+ years old. Let’s see if you folks can help me narrow this down. Thanks in advance.
Splitter hydraulic issue
- Thread starter Slimdusty
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Hi! Does the timber actually split? If it does the job, this only means that 700 lbs is enough pressure to get through the job. There needs to be a resistance so the pressure can build up. If the piston is moving, pressure cant build.
If the two stage pump stays onto the high volume side it would more than likely kill your engine. It sounds to me like a leaky cylinder seal or possibly your relief valve not working correctly
No, it will not split, just “deadheads” and the pressure sits at about 700.The engine does not stall out either, although you can hear it load up initially.
So, while troubleshooting yesterday I adjusted the pump, increasing pressure from 600 to just over 700. Above 700 will stall the engine, therefore I backed it off to just under 700. At this pressure the engine does not stall at 3/4 throttle. I believe the relief valve is also working, as I adjusted it just to see, it seems normal. When I cycle the cylinder to end of stroke my pressure quickly builds to 1500 psi, which is where I have always had the relief set.
It seems as though your two-stage pump is not switching over to the high pressure low volume side
Thanks for the help. I agree. Is there a way to verify this, before I buy a new pump. I would rather not buy a pump only to realize the cylinder is leaking. Anything to check/repair on the pump? Its a northern tool 11gpm, and with its age and use probably not worth repairing.
Yesterday in troubleshooting I adjusted the pump from about 600 to 700 psi. Is this the pressure that would normally trigger the high pressure low volume side? Should I try to adjust the pump down to a lower pressure to see if it goes into high pressure low volume side?
Well you kind of already did. If I read correctly above you advanced the relief past the pressure required to trigger the pump to the low volume side. It then stalled your engine. If my comprehension is correct you pretty much already diagnosed it
Hmm ok i guess I did, thanks for the help. If I understand correctly, when i cycle the cylinder to end of stroke and the pressure quickly builds to my set relief pressure of 1500, that is evidence that my cylinder seals are ok, correct?
That is how I am reading it as well. But please keep in mind that long distance diagnosis is more of an art than a science. This is my best guess
Understandable on your disclaimer. So lets assume I am going to buy a new pump. Current pump is a 13 gpm, powered with a 6.5 hp motor, relief set at 1500, this setup works well for the wood i split. Tonnage wise it is pretty low, I forget the exact tonnage right now. It is also a bit slow. I would like to upgrade to a 16gpm pump if possible. Any issues with this, assuming I keep the relief pressure on the low side, I think the 6.5hp engine could handle it, but I could be off track as well.
It's not just the pressure relief, it's the switchover point from hi flow/lo pressure, to lo flow/hi pressure...that's more critical as it's the one that would stall the splitter the most. Now, that said, yes I think you can turn them both down enough to work. I have a 16gpm pump being run by a 8hp and it just plays with it.
Pay attention to the gpm on the lo flow/hi pressure side, they are not all the same...if you get one with a lower gpm you will almost surely be fine.
Mine is around 4gpm on the lo flow side...if you can find closer to 3, you'll have no issues
Pay attention to the gpm on the lo flow/hi pressure side, they are not all the same...if you get one with a lower gpm you will almost surely be fine.
Mine is around 4gpm on the lo flow side...if you can find closer to 3, you'll have no issues
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Surplus Center has an 18.5 gpm pump with 3.0 on the lo flow side...3gpm x 3000 psi = 5.2 hp for the low side relief point.
On the hi flow side you'd have to to turn the pressure switchover point to about 500 psi...that would use 5.4hp at 18.5gpm.
On the hi flow side you'd have to to turn the pressure switchover point to about 500 psi...that would use 5.4hp at 18.5gpm.
Good info., well said and much appreciated. I had this thought in my head about the switch over pressure, your explanation helped me understand. Here is the specs on my current pump, the 1053 model.
2 questions. Do these “log splitter pumps” pretty much share the standard 4 bolt mounting pattern? I would hopefully use my existing bracket with the new pump. Next question is, this pump is way cheaper than the 16gpm replacement that i was originally looking at, is there much difference in quality with the pumps out there or are they just renamed and made by a couple of companies.Surplus Center has an 18.5 gpm pump with 3.0 on the lo flow side...3gpm x 3000 psi = 5.2 hp for the low side relief point.
On the hi flow side you'd have to to turn the pressure switchover point to about 500 psi...that would use 5.4hp at 18.5gpm.
Log Splitter Hydraulic Pump Horsepower Calculator
Calculate a Hydraulic Pump's Horsepower Needed for a Log Splitter
logsplitterplans.com
Not all of the pumps available give the specs needed to break it all down though (like the low flow output)
I believe many of the pumps use the same bracket...but once you get over say 20(?) gpm pumps I think they use a larger one.
I'm sure there are different qualities of pumps out there, but it seems most of the consumer grade splitters use the aluminum bodied pumps like I linked, which generally hold up pretty well.
Surplus Center has some pretty good prices on things though, so might not be a fair comparison.
I'm sure there are different qualities of pumps out there, but it seems most of the consumer grade splitters use the aluminum bodied pumps like I linked, which generally hold up pretty well.
Surplus Center has some pretty good prices on things though, so might not be a fair comparison.
I ran the numbers comparing my old pump to the new pump that you suggested and agree, it should work as long as I dial down the switchover pressure. Besides, for a $100 it’s pretty modest investment. Worst case scenario I have an 8hp honda collecting dust I could always use if needed. I will report back once installed
Unfortunate update! I received the new pump and installed it this morning, but it continues to not kick into the second stage, or so it seems…. I adjusted the new pump pressure down and back up to the point it would stall the engine. Now am I to assume the cylinder is leaking internally?! Argh…..
Yup, must be.
The good news is that rebuilding the cylinder is pretty easy, and not terribly expensive (if you diy it)
What kind of splitter is it?
I repacked a DHT 25 T cylinder without even taking it off the splitter...only lost about a half pint of oil too.
It’s a homemade splitter. I bought all the components from a widow, (axle, wheels, beam, cylinder, pump, and valve) and reconfigured the setup to how I wanted it. The cylinder is a 5” cylinder with 1 1/2” rod with the knife welded on to the rod. It’s functional but janky. I had previously thought if the cylinder ever fails I would replace it with a more standard 4” cylinder 2”rod. Maybe the time has come for a new cylinder and knife design.
I built one a couple years ago, used the 4" version of this one (much cheaper!) https://ruggedmade.com/log-splitter-cylinder-5-bore-30-stroke-3-5-rod-2-375-rod-end.html
I like it, large ram (fast return!) 3/4" ports, and at the time it had a great sale price, with free shipping!
Even with a wedge on it, it has plenty of power... very rarely see over 1500 psi to pop a log open, and if you have a knife design instead, it would be even less...if I build another one, (vertical table style) I might try a 3" or 3.5" cylinder.
I like it, large ram (fast return!) 3/4" ports, and at the time it had a great sale price, with free shipping!
Even with a wedge on it, it has plenty of power... very rarely see over 1500 psi to pop a log open, and if you have a knife design instead, it would be even less...if I build another one, (vertical table style) I might try a 3" or 3.5" cylinder.
How is the cylinder constructed?
Some are very easy to take apart
snap a pic of it if you want any help to take it apart. You got nothing to loose if you decide on replacing.
Placing a gauge inline would tell you if the cylinder is leaking, instead if using the parts cannon
Some are very easy to take apart
snap a pic of it if you want any help to take it apart. You got nothing to loose if you decide on replacing.
Placing a gauge inline would tell you if the cylinder is leaking, instead if using the parts cannon
