Tudor, can you give more information about this one??Like the Aux pump and such??
The pump has a displacement of approximately 0.39 cu-in, sized for the loader. It's a bit small for the splitter, but it does the job. The one on there now (replaced in '96) has a 5/8" shaft which seems to be hard to find in the new pumps. The 1/2" shaft twisted off on the old pump.
At 1500 psi, the 3.5" cylinder has 7 tons of push. That's been enough to split about 98% of the maple, birch, and beech logs that I've dealt with. An 8 lb maul and a 12 lb sledge can deal with the rest, if I'm feeling ambitious.
If you want more speed, you need more pump dispacement. If you want more force, either a higher relief valve setting or a larger diameter cylinder is required.
My setup has a Cross 10 micron filter in front of the pump and the valve set is permanent to the tractor. The splitter has the cylinder and the 2 hoses with quick connects to join to hoses from the valve set. The reservoirs are the loader's posts, about a gallon of Dexron ATF each. Work lines are 1/4" hose and the pump supply and reservoir crossover hoses are 3/4". A bigger pump will require bigger lines.
This was one of my first hydraulics projects and is missing the system relief valve that should be right after the pump. With the location of the loader and auxilliary valve sets being at some remove from each other, it's difficult to operate both under load at the same time and there is little risk to destroying the pump. That oversight will be corrected when I refurbish the tractor which has been parked for several years.