Log splitter will only split at low engine RPM

[nezwick]

Hey everybody, first post so go easy! I don't know a whole lot about hydraulics but I will try to describe the problem as best I can.

So I picked up an older, very heavy duty, homemade log splitter from Craigslist the other day. The seller and I thoroughly tested the machine by splitting a whole bunch of hickory and oak logs from his wood pile, so it was working fine when I left his place. Then a couple days went by before I could actually use it at home. Today, when I tried splitting some wood, it was being REALLY temperamental, and it seems like an unusual problem.

The only way I can get the cylinder to have enough force to push through a piece of wood is to slow the engine WAY down. At a certain speed, my guess is around 1200 RPM (just by ear, haven't connected a tach yet), I can hear the system start to build pressure and the cylinder powers forward through the log at a pretty decent pace. I hear a "whooshing" or "whining" noise when it starts working. Like all of a sudden it realizes it needs to build pressure. Of course since the engine RPM is so low when the load is added, the engine wants to stall so I have to raise the throttle to compensate. MOST of the time, I can make it the whole way through the split by manipulating the throttle, but sometimes the governor wants to give it too much throttle so I lose all my pressure (and also all the noise in the hydraulic system).

At "normal" operating speed (which I assume is somewhere between 2000-2800 RPM), the cylinder will move back and forth but very slowly. It just won't split anything. Another symptom I notice is that the engine will actually bog down more when the cylinder is RETRACTING than it does when it is advancing.

The parts used on this homemade splitter are really hard to identify because there are lots of missing tags and lots of layers of paint. Here's what I know:

Engine is a Wisconsin TJD 18.2 HP inline twin which runs great, so it should have PLENTY of power.

The cylinder is made by Parker Hannifin, has a 6" bore, 24" stroke, and the rod appears to be almost 2" in diameter.

I have no idea about the pump specs, because I cannot find any nameplate.The control valve is made by Prince.

It really is a beast and I got one this big for a reason: lots of big chunks of maple I just can't split with a maul. Really hoping it's something simple and not an expensive repair.

Is this a symptom of air or water in the system? Fluid flush/change first in order?

 

[kevin j]

check everything on the suction side there might be a plugged strainer in the tank, the collapsed hose or the liner coming loose on the inside of the hose. I suspect at a certain flow rate the restriction is too much and there’s cavitation in the pump. that’s diagnostics from a distance of course

 

[triptester]

Could be a damaged or broken spring in the pressure relief. Another possible cause would be a hydraulic hose that is delaminating internally restricting flow in the return hose between the front of the cylinder and the control valve.

 

[jetsam]

Hey everybody, first post so go easy! I don't know a whole lot about hydraulics but I will try to describe the problem as best I can.

So I picked up an older, very heavy duty, homemade log splitter from Craigslist the other day. The seller and I thoroughly tested the machine by splitting a whole bunch of hickory and oak logs from his wood pile, so it was working fine when I left his place. Then a couple days went by before I could actually use it at home. Today, when I tried splitting some wood, it was being REALLY temperamental, and it seems like an unusual problem.

The only way I can get the cylinder to have enough force to push through a piece of wood is to slow the engine WAY down. At a certain speed, my guess is around 1200 RPM (just by ear, haven't connected a tach yet), I can hear the system start to build pressure and the cylinder powers forward through the log at a pretty decent pace. I hear a "whooshing" or "whining" noise when it starts working. Like all of a sudden it realizes it needs to build pressure. Of course since the engine RPM is so low when the load is added, the engine wants to stall so I have to raise the throttle to compensate. MOST of the time, I can make it the whole way through the split by manipulating the throttle, but sometimes the governor wants to give it too much throttle so I lose all my pressure (and also all the noise in the hydraulic system).

At "normal" operating speed (which I assume is somewhere between 2000-2800 RPM), the cylinder will move back and forth but very slowly. It just won't split anything. Another symptom I notice is that the engine will actually bog down more when the cylinder is RETRACTING than it does when it is advancing.


The parts used on this homemade splitter are really hard to identify because there are lots of missing tags and lots of layers of paint. Here's what I know:

Engine is a Wisconsin TJD 18.2 HP inline twin which runs great, so it should have PLENTY of power.

The cylinder is made by Parker Hannifin, has a 6" bore, 24" stroke, and the rod appears to be almost 2" in diameter.

I have no idea about the pump specs, because I cannot find any nameplate.

The control valve is made by Prince.



It really is a beast and I got one this big for a reason: lots of big chunks of maple I just can't split with a maul. Really hoping it's something simple and not an expensive repair.


Is this a symptom of air or water in the system? Fluid flush/change first in order?

Run it back and forth for a while and then look in the hydraulic tank with a flashlight. If you see a milkshake, it's water contamination. If it looks foamy, it's air contamination.

If it's got water or air in the fluid, step one is to figure out how it got in there and fix it. Step two is to change the fluid (or maybe not if it just had air in it, and it looks pretty clean).

Pull the filter too... can you see any chunks of hose in there?

 

[Ashful]

I think the three answers above already nailed most of what I’d be looking at. Just a few more thoughts, sort of related to the answers you already received. Was it sitting outside? Was it below freezing? Did he have it warm when you tested before?

I’d be getting it warm and draining the hydro fluid. New hydro filter, refill, test. First thing I do on every machine I drag home is replace all fluids, so I know where to begin my own maintenance schedule.

I can help you check the design, if you think it’s a design issue. Measure fittings on the pump, and all line sizes, if you want to go there. NPT fitting sizes are roughly 1/4” under their OD measurement. Hose barbs (suction side) are their OD measurement.

 

[zrock]

did you check fluid level?

 

[nezwick]

Thanks for your replies!

There is no external filter to check or change, but the guy said there is an internal cartridge filter underneath a metal plate on top of the tank - which I assume just gets cleaned out with kerosene. Once I get an opportunity to go outside today, I'll start by taking off the filter cover and checking that out. That will also give me a chance to look at the condition of the fluid. There is a sight gauge on the side of the tank for checking the fluid level, but it's too dirty/cloudy to be useful right now. In general, where should the level be in relation to the suction side hose? Or should the tank just be "full".

It was stored outside and unfortunately will also be stored outside here as well. Now that you mention it, it was raining really hard for the trip home (over an hour drive), so maybe some water got into the system somewhere. Or maybe a bunch of trash in the tank was knocked around.

The weather when I bought it was low 40's and raining. The weather yesterday was mid 30's.

We'll look at design issues once we get through the basic cleaning. I'm guessing this was built in the 1950s-60s so I'd have to assume at some point in its life it worked correctly.

 

[Ashful]

Level at suction hose must never dip below fitting, while running. Really, as long as the level is somewhere up close to return, you should be good. You want some head space in the tank.

I'd drain and trash all fluids, spin a new filter on there, an refill fresh. Most of us run ATF in our splitters, easy to come by.

If storing outside, keep a tarp over it. I do that with my own splitter, just to avoid having to trailer it back up to the barn each time I use it.

 

[nezwick]

Here’s what the fluid looks like after sitting overnight... I’d say it needs changed. It’s plenty full. Water infiltration?

 

[jetsam]

Ew! If it had just been running I'd say water contamination. If that picture is after sitting overnight, it may be water plus the hydraulic fluid is from 1960 and has decomposed into something that stays mixed with water?

Definitely change the fluid and filter. I'd give it just enough fresh to keep the intake covered and run it a little (inch or two out, then in) to get some of that glop cycled out of the lines and pump, and then change it again.

 

[Ashful]

Yeah, you're beyond "single change" territory. Double-change time. Only other option would be to remove every damn line and fitting, to try to get all that crap out of there, but I'd not try it on an old machine.

Run, drain, fill, run, drain, fill.

 

[nezwick]

Got it! Yeah I thought that looked terrible. I'll get some ATF at NAPA today or tomorrow (temp is supposed to be almost 70 tomorrow so that should help the fluid flow). I think the guy said it takes over 5 gallons of fluid. This stuff doesn't look half as bad as what came out of the rear end of our '44 2N when I first got it. It was chunky and looked like butterscotch pudding.

I did get the sight gauge cleaned off and here's what it looks like. Also, despite the condition of the fluid I managed to get a little pile done yesterday. It will bust through just about anything and I can't even imagine how powerful it will be once the fluid is correct. We burn about 2 cords a month to keep the house warm.

 

[kevin j]

I think there are two issues
one the speed which seems to be related to flow rate and engine speed. the other issue is fluid quality which definitely needs a change and flush.

is that sight gauge after running? Then that would be sucking air and a loose connection or suction side issue or shaft seal possibly
if the sight gauge is that way after sitting overnight then it’s fluid compatibility or water or mixed fluids who knows what people have dumped in there and added together

 

[Ashful]

6” cylinder = 28.26 sq.in. = 84,780 lb. @ 3000 psi = 42 tons. Yeah, it’ll split just about anything.

 

[nezwick]

That sight gauge is after sitting overnight with no use, just the movement of towing the splitter from the wood pile back to the barn. Picture was taken at the same time as the view from the top of the tank.


42 tons!! Go big or go home! What I really wanted was a 3 point PTO powered splitter, but I searched for months and couldn't find anything. Brand new ones are way above our budget. So I "settled" for this one, and I'm pretty sure I'm glad I did.

 

[sportbikerider78]

Did you say ATF? Hydraulic oil and ATF are not the same thing.

I'd drain that thing asap.

 

[nezwick]

A couple posts ago, Ashful suggested replacing whatever that stuff is with ATF. I hope I didn't just cause one of those famous internet "what's the best oil" wars.

I'll fill it with whatever is correct. Never owned a log splitter before so I wasn't sure what to use.

 

[blades]

Might want to check the pricing between ATF and say AW32 Hydro oil or 303 tractor fluid- likely being less costly than ATF labeled products although very similar. My splitter has been running on W32 for 15 years ( yes it has been changed a few times in that span)

 

[Ashful]

A couple posts ago, Ashful suggested replacing whatever that stuff is with ATF. I hope I didn't just cause one of those famous internet "what's the best oil" wars.

Not at all. Some run various viscosities of Hydro fluid, but if you check the manual of most homeowner grade splitters today, you’ll find they just call out ATF. There’s nothing wrong with ATF, it’s more easily-obtained (Walmart carries it) than most other options, and its temperature range is well suited to where most are using their log splitter.

If you go with another option, consider the range of usage temperatures. Too thick, and you’re going to have fun starting it with a live pump connection (no clutches on log splitters). Too thin, and you’re going to have a wet slippery hand on that control valve.

Either one will work perfectly well. You just need a non-compressible non-detergent oil. Heck, my zero turn runs 15W-40 detergent oil in the hydro case, per John Deere. Non critical, although this one is a nightmare to start in the cold.

 

[nezwick]

Cool. I should have access to just about any lubricant they make. I assume I'll be doing most of my splitting in the fall, through the winter, and in the spring. Doubtfully in the summer heat, but maybe. The old farmer's rule is to have all the wood split and stacked before Easter... yeah right.

This splitter actually has an in/out gearbox thing in between the engine and pump, so while it's not a clutch, it's still a neat way to disengage the hydraulics when needed.

 

[kevin j]

OK if that sight gauge is from sitting over night it probably isn’t water because that would’ve settled down ( unless it has detergent motor oil in it which will emulsify water) and air would’ve come out. it’s probably chemical incompatibility from something that was dumped in there over the years. or most likely a combination of all of those above.

you might want to drain the fluid disconnect the hoses cycle the cylinder in an out to get as much out as possible and then instead of partial filling the tank and cycling a few times try putting the pump suction into a bucket of new fluid. start it up with the valve handle held moving the cylinder in one directio. as soon as it gets to the end of stroke move the valve and cylinder to the other direction. as soon as it reaches the end of stroke back shut off the engine. This way you’re pushing fresh fluid through the system rather than sucking out of the tank and recycling and moving a mixture around the system. Then drain and clean the tank hook everything back up. put enough fresh fluid in the tank to cover the suction and run it and cycle it a few times. Then see the what the condition of the fluid in the tank is. And decide whether to drain that or to just continue to fill it with fresh fluid.

this is pretty crappy looking and it’s a little bit more involved than just a normal drain and refill. But not terribly complicated because it’s such a small system.

A bad day is a 1000 gallon system with 22 pumps, another dozen motors and 50 cylinders when the tank looks like panning for gold with sparkly pieces of brass and silver everywhere.
A large industrial plant or oil platform would be even bigger and worse but they have whole different levels of contamination control systems.

I saw about every possible fluid added to hydraulic tanks usually accidentally from unlabel container that was on the machines or occasional cases of sabotage. We saw antifreeze, battery acid, used engine drain oil, an unidentified biological contaminant of some sort. that one kept regrowing about a week after that system would be cleaned and flushed thoroughly scrubbed and refilled. After assorted attempts with biocides and two or three cycles of cleaning eventually they scrapped the machine because it was quite old and it was a 500 gallon system I think.
I’m sure I’m forgetting a few more.

 

[JimBear]

Cool. I should have access to just about any lubricant they make. I assume I'll be doing most of my splitting in the fall, through the winter, and in the spring. Doubtfully in the summer heat, but maybe. The old farmer's rule is to have all the wood split and stacked before Easter... yeah right.

This splitter actually has an in/out gearbox thing in between the engine and pump, so while it's not a clutch, it's still a neat way to disengage the hydraulics when needed.

I believe you said you were going to NAPA for your oil, they should have exactly what you want & may even have it it bulk so if you have your own jugs/buckets it could save you some money also. Our local NAPA carries bulk oil from Northland and several other brands in 5gallon - 1quart sizes. As far as oil type I believe Hy-Tran oil is cheaper than ATF. CASE/IH calls it HY-Tran, JD calls it HY- Gard or something similar but that’s what they use in the transmission & hydraulic systems of their tractors. My Dad & brother use their chore tractor year round, when it’s negative temps the loader is a bit slow but after a couple of cycles it works just fine. I would buy 2 filters & the cheapest thing I could get for the first clean out, then change that filter along with the oil, then put some better oil in on the subsequent refill. You may even be able to sell that oil to someone with a used oil burning heater. Water shouldn’t be an issue if they have a skimmer.

 

[jwfirebird]

some times tractor supply has the universal rear fluid on sale, i use it in alot of stuff, some quads, splitter, tractor, etc. it normally 20 for 2 gal for the wet clutch 50 for 5g sometimes they have it for 40

 

[Tar12]

Go with whatever is cheapest as you are tossing it anyway...I will have to say you win first prize for the worst hydro fluid I have ever seen!

 

[jetsam]

Go with whatever is cheapest as you are tossing it anyway...I will have to say you win first prize for the worst hydro fluid I have ever seen!

I'm going to give it second prize, but only because of this:

This stuff doesn't look half as bad as what came out of the rear end of our '44 2N when I first got it. It was chunky and looked like butterscotch pudding.

"chunky butterscotch pudding"