Hydraulic question

[Chris S]

I'm running dad's 25 yr old Northern splitter, and whenever I have it is when things go wrong. I don't want him splitting anymore, so I'd rather bring him the wood, and let him just worry about stacking & burning but I digress.
Recent symptom is that the piston extends to the log, but has no power to push through. With no log on the beam it will go back & forth, just has no power.
I changed out the oil which hadn't been done in a few years, and cleaned the pick up screen, which was mucky.- no change.
Before I order a new hydraulic pump, is there something else I should be checking?

Thanks
Chris

 

[webie]

Just check out your control and start it up and hold the control down and see if it makes the motor grunt down or not . If it doesnt it could be a problem with your control pressure limit .
This really sounds to me like you may have had some contaminated oil , Now besides the pickup screen is there a hydraulic oil filter too , I am thinking there should be .
We had a similar problem with about a 30 year old speedco splitter, Turned out to be caused by moisture in our oil , we ended up changeing the filter twice and had to work the thing till it got good and hot , the pump was sticking only in the high range and would choke out the motor or would get stuck in low and barely move , Anyways we had no splitting power , Now there is the posibility the packing in your ram may have blowin out again this can be figured out also in step one try to make it grunt down .........Need to elimanate items in your system . There is only oil a pump a control and a ram .
I am no expert just been around awhile .

 

[triptester]

Check the connection between engine and pump to make sure it is not slipping.

To check the pump you can remove the return hose and plug the opening in the control valve. Disconnect the spark plug wire. After a couple of pulls on the starter rope it should become very difficult to pull if the pump is good.

 

[leaddog]

sounds like the relief valve is stuck open, The relief valve is usually on the control valve. You can take it apart and clean it but you need a gage to reset it when you put it back together. If when you dead head the piston and it doesn't load the engine it is probably the valve is stuck open.
leaddog

 

[LLigetfa]

The seal could be gone inside the cylinder or the nut inside loose.

 

[Chris S]

Thanks all
It does not stall , or bog down the engine.
The coupler at the engine is good.
The return hose to the tank is clear. When the piston stops against the log, there is no fluid flowing back to the tank- should there be?

 

[triptester]

( When the piston stops against the log, there is no fluid flowing back to the tank- should there be? )


When the piston stops moving and pressure builds, the relief in the control valve will open allowing flow to the tank or the engine will stall.

 

[Chris S]

Since this is not what is happening- piston stops moving, no fluid back to tank,
It makes me think the pump is shot.

 

[webie]

Did it quit while you were useing it or did it not work after it sat and then you wanted to use it another time. if it quit in the middle of use the pump may be broke If just didnt work after it sat for a while I am inclined to think that the pump is dirty or blocked . I would be more thinking i would take the pump apart and see if you can locate a problem than to just buy a new one . Contaminated oil usually with water can make these things act wierd but ussually with some patience you can get them working again .
No mater what there should always be fluid going back to the tank when ever the pump is running.

 

[webie]

Check the inlet screen again it could be a whole bunch of dirt got loosened up when you changed the oil and clogged the screen back up .

 

[triptester]

Another possible problem could be that the check valve between the the high and low pressure sections is stuck open. This could cause the fluid to recirculate without building pressure.

 

[Chris S]

Once again, thanks for the responses. It sat for about a week, then when I went to use it N/G. I will try the various suggestions, before buying a pump, but not today, I have to do a few things for my honey, that don't include splitting wood, plus there's still too much snow covering it up.

 

[dirttracker]

I had a Barnes 2 stage pump go out on my splitter and it acted just like you were describing. If you have a 2 stage, pull the plug on the relief valve and make sure it's closing (no crud in seat, broken spring, etc). If thats not it, it sounds like you have a bad pump. If you take the pump apart you'll probably see wear on the high pressure section. I my case it was from having the suction screen undersized. Mine failed after using it in fairly cold (0 F) weather. The suction screen was acceptable at warmer temperatures, but when the oil was cold it caused too much restriction on the pump inlet, resulting in cavitation and death of the pump.

I don't know if you can tear down the Barnes style 2 stage pumps and put them back together easily. The pump was easy to tear down, but you may need to replace the brass gaskets between the pump stages to keep the pump from leaking after reassembly. FWIW you may be able to reuse the old gaskets as long as you don't tear them. Depending on the pump MFG, you may have trouble finding replacement parts. I was not able to easily find anything for the Barnes pump I had, but I did not look too hard after I figured out the HP stage was shot.

 

[Gooserider]

Suction screens will make you eat pumps if they get plugged up at all... There is a school of thought which I agree with 100% that says you should NEVER have any sort of filtration or other restriction between the tank and the pump inlet. Clean oil with a regularly changed filter on the return side is not going to magically put dirt on the inlet side - just be careful not to allow contamination when filling up the tank. In essence the idea of no suction side strainer is that anything fine enough to catch a pump damaging particle is going to cause enough flow restriction to kill the pump via cavitation. Anything coarse enough to not cause cavitation isn't going to do any useful filtration. Thus you are better off not having any suction side filtering, and concentrate on keeping the contamination from happening in the first place...

(The guy I learned this from teaches hydraulic equipment maintenance on high-end, ultra big bux equipment, I figure if it's good enough for that, it's good enough for my thousand dollar splitter...)

Gooserider

 

[JeffRey30747]

Check the suction side hose for a crack or leak. We had a stack of wood fall on ours last week and it caused a tiny crack in the suction hose. It was sucking air in addition to hydraulic fluid and exhibited symptoms very similar to what you are describing. I thought the hi stage of the pump was gone but after finding the crack and repairing it, everything is back to normal.

 

[dirttracker]

Goose, I agree with ya! When I put on the new pump the suction strainer went in the trash. 3 years and many cords of wood later I have not seen any problems with the pump ingesting dirt. I'll never use a strainer again with this type of system, these pumps are sensitive to having a good supply of oil at the inlet and will not tolerate cavitation.

 

[Gooserider]

Check the suction side hose for a crack or leak. We had a stack of wood fall on ours last week and it caused a tiny crack in the suction hose. It was sucking air in addition to hydraulic fluid and exhibited symptoms very similar to what you are describing. I thought the hi stage of the pump was gone but after finding the crack and repairing it, everything is back to normal.

Good idea - also make sure that the suction hose isn't collapsing internally. It should be reinforced inside to prevent collapse, but I've heard of cases where the hose liner separates from the outer and reinforcing layers, with the result that the hose looks good on the outside, but doesn't let enough flow through on the inside...

Gooserider