any hydraulic experts out there?

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bruce56bb

Feeling the Heat
Nov 18, 2005
336
Flint Hills of Kansas
i'm having trouble with my splitter. after it has been ran a while(an hour or so), when the ram reaches the log it doesn't imediatly kick down to the 2nd stage. sometimes it can take as long as 10-20 seconds to kick down and split it. the fluid looks good and there is probably 5 hours on the filter.any suggestions?
thanks in advance
bruce
 
elk.......it has acted up in temps from 5*-65*. i am unsure of age as it is a homemade unit. i've probably split 4 or 5 cords of hardwood with it this year. i'll have to look for an adjustment screw.
 
pic of the pump
 

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and of the cylinder.sorry about my photographic skills:(
 

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I'd vote for worn pump impellers. Once the fluid heats up and thins out the pump isn't building the pressure it needs too. Could be checked with a pressure gauge inline I guess. Possibley also worn cylinder seals that are allowing fluid to bypass and return to the tank, but usually when this happens the cylinder also tends to lock up.

I've had both issues with an old Craftsman splitter I've got.
Willhound
 
hound...if it is the impellers are they fixable or do you just replace the pump? i wonder if adding more fluid to the resivoir could possibly help? i also assume if it is the cylinder seals that it has to be rebuilt? thanks bruce
 
Silly me, I didn't even think of suggesting that you check the fluid level in the reservoir as this is also a classic symptom of low fluid. I just assumed that you had done that. However, if is not low, do not overfill it, as this will not likely help. At best the excess will just puke out the vent, at worst, it could cause problems for returning fluid to the tank.
As far as pumps and cylinders, most can be re-built. Pump might be more difficult if it was an older brand and parts can't be found, but a replacement pump should not be too expensive. Most cylinders are easily re-built since the seals are pretty common. Cylinders usually only need to be replaced if the actual piston is damaged, or worn way past serviceable use, but when this happens, you usually see the leak long before. Any industrial hydraulic shop should be able to do either one for you.

Willhound
 
hound...thanks for the help. it does look like the reservoir holds roughly 5 gallons with maybe 3 gallons in it now. should i add another gallon and give that a try?
 
That would be the first thing. Most I've seen run fairly full, not right to the top, but at least 3/4's full, or more. Sometimes there is a sight gauge, looks like a little round window in the side of the tank.
Fluid is pretty cheap compared to replacing pumps and seals.
And the more I think about it, the more it sounds like low fluid. It's usually the simple things that cause problems.
 
the picture were so dark they were useless. Anyway only have 60% hydro fluid is probably the problem. One can buy Hydro fluid fairly cheap at Walmart in 2 gallon containers in the Automotive section
W hound is right sounds like low fluid. If that does the trick great I work on my heavey equipment so I have rebuilt cylinders and all sorts of valves usually o rings let go. Lets hope it is just low on fluid. I can price out pumps and control valves not real bad cost wise to replace
 
I'm not too familiar with splitters, but if it was the first time I'd ever added fluid, I'd try to make sure I used the proper stuff.

Anybody? Are fluids different enough to be concerned? I remember the old "F" type vs. Dexron type. You didn't want to get those mixed up! I suspect there are others. Does this come into play?

BTW: It looks like somebody barrowed Brother Bart's (or Fred Flintstone's) camera. :)
 
Camera? I thought they were carbon black etchings.


Just kidding.
.
You probably want to use a standard industrial hydro fluid. Its about a 10 wt oil. there are different kinds but you should be OK in this app even if you mix them.

.
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. You will want to retract the cylinder all the way and fill the resivour to within 1" of the top, leaving space for expansion. You also want to keep the fluids topped off to prevent moisture accumulation witch could be your problem also considering the tank has been drawn down.
 
Mo Heat said:
BTW: It looks like somebody barrowed Brother Bart's (or Fred Flintstone's) camera. :)

Ahem. I do my artistry with a chainsaw, thank you.
 
bruce said:
make sure its the right fluid, my splitter has 4 gal of atf in it

Heh heh...I'm not sure if this is supposed to be funny or not. ATF has a special forumlation with a balance of friction modifiers and lubricating agents. The lubricating agents are added to help keep bushings, bearings, and sliding parts of the transmission happy, but the friction modifiers are added actually raise the coefficient of friction of the fluid to help the clutch plates grip. ATF is a careful balance of "slippery and sticky" if you will.

Straight hydraulic systems have no need for any friction modifiers as there is no need for any part of the system to "grip". You want the highest lubricity and lowest coefficient of friction possible for maximum effieicncy. Additionally, ATF fluid usually heats up beyond 212F during service which helps boil moisture out of the system. Small hydraulic systems usually do not reach this extreme temperature and must deal with condensed water in a different manner. In the end, hydraulic systems and automatic transmission have vastly different fluid requirements.

I run Wal-Marts Super Tech "R&O Anti-Wear Hydraulic Oil" in my splitter with good results so far.

Good Luck,
Corey
 
dadgumit! i added fluid but it is still acting up. is it possible the high pressure bypass is not working properly or is there and adjustment to it? please, no griping about my updated pump picture....i do not make my living taking pictures.
thanks


ps corey.......if this gets too complex for me can i just drop it off at your house for you to fix?:)
 

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I don't know if I'd term myself a hydraulic "expert" but if you are in the Lawrence, KS area, swing by...we'll have a beer and do some trouble shootin'.

Going back and reading your original post, it seems that the issue is the splitter works fine for ther first hour or so, then it gets to a point where takes a long time to kick in the second stage of the of the pump once the ram hits the log? This sounds a little different from the 2 stage pump I use. In my setup, the first stage (actually two sections of the pump working together) moves the ram when it is free and also on easy splitting logs it may run all the way through. It usually only kicks in the second stage (drops out one section of the pump) when I hit a knot, crotch, or when splitting elm. I believe my stage change is set at about 1100 psi (and is adjustable)

If your pump is similar, it sounds like you are not developing the required pressure to cause it to switch stages. (It also sounds like the switch may be coming a bit early if it switches as the wedge first touches the log, but that is another thread)

So you now have good oil level and a clean filter. There is usually also a screen on the intake side of the pump (usually down in the oil reservoir) You may want to check to make sure the screen is clean and make sure the tank breather is clean. Beyond that you may try to adjust the switchover point for the stages.

I'd also be curious to know if the symptoms come on all at once (that may indicate something mechanical operating improperly, like a valve getting stuck) or if they build up gradually over the hour (that may indicate leaking seals, thin oil, or blocked inlets)

Hope this helps,
Corey
 
corey....i'm not sure i feel comforable going to enemy territory (lawrence, darth vader etc) when i am a died in the wool wildcat(council grove,the good guys ya know, john wayne ect):).
but seriously, the symptoms gradually get worse the longer it's running.
i heard the jayhawks won again today. were they playing northeast new orleans community college of the blind again?
bruce
 
cozy heat for my feet said:
bruce said:
make sure its the right fluid, my splitter has 4 gal of atf in it

Heh heh...I'm not sure if this is supposed to be funny or not. ATF has a special forumlation with a balance of friction modifiers and lubricating agents. The lubricating agents are added to help keep bushings, bearings, and sliding parts of the transmission happy, but the friction modifiers are added actually raise the coefficient of friction of the fluid to help the clutch plates grip. ATF is a careful balance of "slippery and sticky" if you will.

Which raises the musical question "Why did the Duerr manual require that I use Dexron ATF in my splitter?".

I know hydro oil and ATF are different (old Chinook mechanic here) but I wasn't going to take any chances on the warranty. Which isn't an issue after running it with the ATF for 18 years now.

And actually starting to give some thought to draing and changing it for the first time.
 
Awww Bruce, we aren't that bad! I could even turn off the Darth Vader theme music and shut off the "spooky fog" machines we've placed on all the main roads into town. Seriously, though, I'm a transplant to Lawrence, so I'm not too concerned if you support the red and blue or the...what is that wildcat color...lavender? :)

BrotherBart - Does look like a good case for ATF if the manufacturer said so. There are probably millions of power steering pumps out there running on ATF as well. Probably one of those things that will work perfectly fine and save from having to buy yet another fluid type. But in a pure hydraulic system, I still don't see where there is any use for the friction modifiers found in the ATF.

Corey
 
corey, i'm still laughing about the fog machines:).
you mentioned "and make sure the tank breather is clean" . my tank does not have a breather, could this be the problem?
 
Bruce
Some have a seperate breather valve, but most (at least that I've seen) are vented throught he cap with either a vent hole, or a double lip type trap thing. Usually there is a piece of foam in the cap covering the hole (tiny small hole) that you can remove and clean any gunk out.

Willhound
 
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