No cylindder pressure....

mrcaptainbob · Nov 14, 2013

There is no return filter. The first thing that happened to this unit was when the hose from the ram end to the valve blew. The wire wrap was exposed in places and was rusted. I replaced that. The splitter worked fine after I cycled the air out of it. Did about a truck load of easy-to-split oak. Then it quit working. No pressure to split anything. It enters a six by six and presses the wood about an 1/8" onto a really sharp blade. The return will hold the detent position, but will not kick off when the travel is complete. The rpm's drop by maybe 25 or 50. Hardly noticeable. The cylinder does move slow, but, even though there'd be a restriction someplace, would not pressure still build? Since it was seemingly instant when it happened, could that be from a pump not pumping? I believe it is a van pump. Is it possible the vanes are stuck in position? Maybe I should pull that and check it out? I look in the tank and can see oil movement at three positions. Fore/aft/centered. The detent and relief springs are not broken.

wdchyd · Nov 14, 2013

Just pulling stuff apart is not a good idea.....you'll end up with multiple problems

You need someone with a flow load/meter to rule out pump flow and pressure before disassembling any components....otherwise you will just be spinning your wheels and digging in deeper

Egon · Nov 15, 2013

As mentioned disconnect the discharge hose before the control valve and check for flow. After you get flow start looking at the splitter control valve.

oldnslo · Nov 15, 2013

wdchyd said:
Just pulling stuff apart is not a good idea.....you'll end up with multiple problems

You need someone with a flow load/meter to rule out pump flow and pressure before disassembling any components....otherwise you will just be spinning your wheels and digging in deeper

Very good advice given here. The flow load/meter will give you the best information. A damaged pump will produce flow at no load so just looking at flow from a hose under no load doesn't tell you much.

mrcaptainbob · Nov 15, 2013

YIKES! I looked into 'acquiring' a flow/load meter, but I'd be better off just getting a new splitter for the price of some of these!! I'll do two things. One is to check the flow rate as J-J suggested. The next is to get a pressure gauge and find what the pump is producing....or can produce. There is a tag on the pump that says how many gallons per revolution is produced. I bet I can manually give it twenty or so revs and multiply it out for a close-enough flow. Frankly, it appears more of a pressure issue than flow, but I'm trying my best to follow the suggestions of my expert friends here (relative to the finances....).

J_J · Nov 15, 2013

mrcaptainbob ,

With out having to spend a lot of money, to check a hyd pump, you can put a relief valve in the pump circuit and use a needle valve and a hyd gage to put some resistance on the pump. Put the hose in the reservoir for the expended fluid..

Set the relief valve about 2000 psi, start engine and slowly turn down the needle valve. If the pump is working good, it will build up pressure as you turn in the needle valve, and if it starts relieving at 2000 psi, then you can assume the pump is working up to that pressure.

If you can not build up the relief pressure, then the pump is bypassing and needs some work or replacing.

A good hyd shop can also test your pump for shop labor, about $45 to $75.

mrcaptainbob · Nov 15, 2013

Two great suggestions. Thanks, J-J.

oldnslo · Nov 18, 2013

captain bob,
Do you have a brand name or model or both for this pump. You stated that you think it is a vane pump.

Does the oil movement in the reservoir continue when the cylinder has stopped moving and the directional valve is held in the shifted position?

mrcaptainbob · Nov 18, 2013

It's a Republic pump. Not sure of the first character, I think the info is:
Model: 0212 3S2 AB
RPM: 2000
PSI: 2200
cu "/rev: .364
It appears there is oil movement in all positions. I presume I could verify by removing the line to the tank in port.
Frankly, I was VERY surprised to see the pump shaft had been damaged at least twice before. I'm sure that shaft originally had but one key way. It got buggered up, then a new one was cut. And that was buggered up too! And...the key was sheared. So I cut yet a new key way and made up a new 'key' for it. And since the old set screw could not be removed, I drilled/tapped for two 1/4-20's at the 120* positions from the key slot on the coupler. It's nice and snug now. I am astonished that the pump would meet such a load so as to rip that key through the shaft! I would have thought something else in that pump or hydraulic line would have gone first.