wood splitter problems

[aranha]

Howdy y'all, bought this wood splitter at a yard sale with a bad pump and installed a new 2 stage 11 GPM pump from ebay on it. I have the exact same pump on my other wood splitter and it works fine. This new one won't put out anymore than 500 lbs no matter what adjustments i make to either to the pump relief valve or control valve relief valve. So sent it back and got another new one and it does the same thing. It doesn't kick down to the high pressure stage at all. I'm lost now and fit to be tied having taken things apart several times over and over again. Any ideas would be appreciated, thanks.

 

[crowbuster]

flow resriction somewhere ? Any street L's in the plumbing ? Shuldnt be, to much of a bottleneck. No galvanized pipe on hydros.

 

[aranha]

flow resriction somewhere ? Any street L's in the plumbing ? Shuldnt be, to much of a bottleneck. No galvanized pipe on hydros.

Not much has changed on it since it came from the factory. One thing I'm thinking about is the hydraulic tank is below the engine and pump so the pump has to suck up the fluid from down under, maybe a vacuum problem during suction? And still can't figure out why it won't kick down to the second stage.

 

[triptester]

A 2-stage pump does not operate like a transmission . It is 2 pumps in one housing, a large pump and a small pump. Both pumps send fluid to the system until a preset pressure is reached usually 600-750 psi. Once this pressure is reached the large pump stops sending fluid to the system, basically shutting itself off until system pressure drops. The high pressure portion of the pump operates all the time.

 

[aranha]

Yeah, I know how a two stage pump works. Where's that adjustment on the pump and how do you adjust it?