JD 4720 Hydraulics

[Furu]

I have a JD 4720.
Specs states 2500psi
17.1 gpm hydraulic flow.
5.1 gpm steering
12.0 gpm pump flow

My question is on the 12.0 gpm pump flow,
If the tractor is not moving how much of that 12 gpm makes it to the rear hydraulic port (power beyond) for available flow.
It runs everything I have asked of it but if I put an implement (post pounder) that requires 12gpm will I be disappointed because the 12 gpm never makes it to the rear port.

 

[ptsg]

This is a common misconception. The HST won't steal any flow from the rest of the hydraulic system. It's just it's own pump and motor tied together and only things shared between the rest of the hydraulic system and the HST is the fluid and the power plant.

You'll have roughly 12 GPM on the loader, remotes and 3 pt at the rated engine RPM. Maybe 2500 RPM? Don't know about that model in particular. I say roughly 12 GPM because when they list those specs, they typically just calculate it using the displacement of the pump at the rated engine RPM and won't really take into consideration the efficiency of the pumps and the losses between fittings, hoses, valves, etc.

You should still have somewhere between 10 and 12 GPM anyways.