Woodsplitter pump woes

I bought a brand new haldex 2 stage woodsplitter pump for my 8 hp briggs & stratton engine in summer 2013. It worked great until this fall. Lately its not building up the pressure it used to. I know hydraulic systems can retain water and for my set-up the pump is at the lowest point. Is it possible it may have been damaged by water collecting in pump over off season? It works well enough for now so thinking rebuilding or dismantling\inspecting pump next week. What I notice is when splitting a piece that normally would be easy, engine bogs down and relief pressure is allowed. My other suspicion is seals\packing in cylinder may be worn and fluid leaking past. I switched to universal tractor fluid this past spring so maybe I need to use a numbered hydraulic oil. I'll buy a gauge (0-3000psi?) and check pressure first. Ideas?
 
Engine is not losing power. It just bogs down like its trying to spkit a difficult piece of wood. The more I think about it the cylinder piston sealing rings could be leaking.
 
Cariboo, do you know how to power check a
cylinder? If you don't, run the cylinder all
the way out, and unhook the line at the rod
end, then with it at an idle, run the lever
to run the cylinder out still, even though
it is all the way out. If the seal is
leaking by, it will leak/squirt oil out the
fitting at the rod end that is open.
Sometimes, if it is a big enough leak, and
you have a 2 stage pump, it goes through the
seal fast enough to think that it hit an
easy spot, making the pump stay in the
fast/speed position, instead of shifting to
the power position
 
RBoots, I have not done that before yet totally understand your directions there. I'll do that over then next few days. Thank you!
 
if cyl leaks, why would engine load down.. and relief valve operate... Only if cylinders dont leak, will the pressure build up.

Why is pressure building up/ engine loading down?? cyls are binding? pump is full of metal? is the splitter dull and no longer sharp?? or wood is dog gone hard. control valve is dead heading/ plugged or line is plugged.

Again.. if cylinders are leaking, pump will not load up and slow down... as the pressure will just leak around the seals in the cyl and return to pump.
 

carb is plugged up and engine has no power and is loading up..

valves on engine are sticking. or something else to reduce engine power??? bad gas, choke sticking,, etc...
 
Hello cariboo4x4,


Put the gauge on the return side, 3000# should be adequate.Then spilt a piece of wood and check the gauge
pressure. If you get a reading, pressure is going pass the seals. You found one problem. Hopefully that
would be the only one,

Guido.
 
No problem Cariboo. Try that as a first step
and see where you are. If you do have water
in the system it would have to be fairly
evident, (ie milky oil), to cause a problem.
Water can and will torch seals, as water
will not compress like oil,but it would have
to have quite a bit of water in it to cause
a problem. But, that being said, cylinder
seals can wear out or come apart with age. I
have seen some of the cheap big box store
splitter pumps have issues. But, they are
usually a Chinese no name pump, not a Haldex
like you said yours is. I don't know the
quality of a Haldex pump, but they must be
pretty popular since I've seen their name
all over, so I'm just guessing that they are
better than the Chinese no name pumps. It
wouldn't be real hard to be better. Most of
the 2 stage pumps have a hex shaped cap just
in front of where the suction line goes into
the hydraulic pump. If you take that off,
there is an adjustment in there that adjusts
the shift between the stages of the pump. I
can't remember of the top of my head, but I
think if you turn it in, it will try to stay
in the "speed" mode longer, and lug the
engine down or possibly even stall it if you
go too far, before it shifts to the "power"
stage. The engine usually doesn't have
enough juice to run the pump at he speed
stage all the way up to full pressure. Then
I believe if you back it out, it will shift
to the slower "power" stage quicker,
sometimes before it really even touches the
block of wood. But, that's what that
adjustment is for. Mine has enough power
that it will usually split dry ash without
shifting down, but if I get into a knotty
piece, it runs fast until it hits the knot
and starts to lug the engine, then it shifts
down. If your cylinder power checks ok, then
plug your gauge in and see what you have for
pressure. If your pressure is low, or goes
over relief quickly, you could have a broken
relief valve sprung or trash in the relief
valve itself in the splitter control valve.
The relief valve can easily be torn apart
and checked over, but make sure before you
start it the first time after reassembling
it, that you have the relief valve backed
out all the way of if it is an adjustable
type. I don't think many of the log splitter
valves are adjustable relief, but some are.
If yours does have the adjustable relief,
you'll just have to use your gauge to set
the relief pressure, while holding it over
relief. The relief should be set based on
what your valve and cylinder are rated for.
My Cross brand control valve does not have
an adjustable relief, but when I checked it,
it was at around 2300 PSI when it as
supposed to be set for 2500. My cylinder is
rated at 2500, but I know they'll take a
little more, so I shimmed my relief valve up
to 2800 psi, everything works together well
set up like that on mine. If you have any
more questions feel free to ask

Ross
 
Took my 30 year old splitter cylinder yesterday to have new packing put in. Seals were completely gone. It was still splitting, but was weak.
Richard in NW SC
 
If it's producing enough pressure to trip the relief valve and bog down the engine, the pump is fine.

Maybe an obstruction somewhere in the system? Or as you suggested something wrong with the cylinder itself?
 
Splitter worked great today yet not splitting like it used to. have two more cords to split tomorrow and then done for season. Going to pull cylinder apart first. Thank you for all your suggestions!
 
Make sure your coupling between the engine and pump isn't slipping on either shaft. If the cylinder were leaking by the oil would return
thru the control valve back to the tank. So I rule that out since you say the relief valve releases. I would check the spring in the
relief vavle. They do break once in a while.
 
(quoted from post at 01:25:57 10/28/16) Splitter worked great today yet not splitting like it used to. have two more cords to split tomorrow and then done for season. Going to pull cylinder apart first. Thank you for all your suggestions!

Why tear the cylinder apart when it hold pressure and will lug the engine? There is either valve or engine trouble.
 
The relief valve is in the control lever spool valve. I'll check that first and also slippage of couplers on eng to pump.
 
Finally got around to troubleshoot woodsplitter. Everything checked out until I took hydraulic line off directional spool valve. Running engine at max rpm and with cylinder extended and spool valve in extended position, oil kept on coming out of line that retracts cylinder. I ran line into 15 gallon bucket and at first got sprayed with oil ha ha. I also took a spare line that I attached to spool valve and ran it into bucket too. After a bit of testing I determined oil was leaking past packing. I disassembled cylinder and sure enough most of the packing was missing or had become hard and brittle. I took remaining packing and piston to the store that sold me o-rings, and flat rings 2-3 years ago. They told me the "regular" o-rings, flat rings are likely not suitable for packing and that they would look into getting me packing that would stand up to high and warm\hot oil pressure.

Is there a big difference in o-rings\flat rings depending on application?
 
(quoted from post at 11:13:56 08/10/17) A hydraulics shop would have a catalog to match up the packing/wipers/orings for your particular cylinder.

We don't have a local shop that does not do just hydraulics. I believe they do have the sources for parts. Its a "shur-lift' cylinder 3.5" ID, Model 3510 U 820255, Ser. 2-32564. I just gave him the model #3510 U. Today is day 2 so I hope he has found something by 4 pm today.

I couldn't find an exact kit on the internet myself. I see images of packing on google for 3.5" cylinder yet I think the images are just an example of packing parts.
"
 
Found out yesterday parts fellow sent cylinder piston to a hydraulics shop to get the correct packing. Thumbs up!
 
Well received seal kit last week. It came into 2 packages. One package for piston and one package for end plug for cylinder. Also a new internal snap ring to hold end plug inside end of cylinder. The package for the piston was one u-cup seal. It was about 3/8" wide and had a o-ring embedded into it to face highest pressure side. It was bit of a workout getting u-cup seal over piston into its groove. I warmed seal up and used hyd. oil to maneuver u-cup seal into position. It did not like to stretch like a regular o-ring. I seen a few videos on Youtube using special tools to insert seals etc.

I had to use a screw type jack laid on its side to push piston and piston shaft back into cylinder. I was a wee worried about pressing piston with piston seal into cylinder since seal had to pass over internal snap ring groove. I used hyd. oil as a lubricant. I did not have much wood to split and the few pieces I had, the ram did not slow down and no leaks. So... so far so good!
 

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