Hydraulic Pump Volume Reduction?

[Spiros]

In an attempt to attach a backhoe to my TC33 I ended up with a Prince PTO pump rated at 21gpm. Even with the engine idled down, the outriggers will go down so fast they dig holes by themselves. In an attempt to feather the controls lightly to gain some form of control, the pto pump clicks very fast and no movement is had.
Full throw of any control results in lightning fast operation.
Is it possible to bleed off some of this massive flow back into the return tank or should I look for a lower volume pump?
Thanks in advance.

 

[J_J]

You should be low volume as the PTO speed is proportional to engine speed.

However, If your tractor is at idle, and the pump volume is too great. then you can use a splitter and direct some of the flow to tank.

Something like this.

6/30 GPM PRINCE PRIORITY FLOW DIVIDER W/RELIEF

or this

3/4 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS175-30

 

[SPYDERLK]

The problem is with the control valve. A suitable one will allow feathering the flow you need to the implement and bleed excess to tank. All loader control valves work this way. It may be that the valve is far too small for your supply, but sounds as if its just an unsuitable design.
larry

 

[Spiros]

Hi guys! I just ordered a variable flow divider and some other bits parts and pieces for my backhoe project.
Thank you very much for the input and I will respond back on this thread with my progress.
Spiros

 

[J_J]

You do know that PTO pump requires more HP than you have available. 26.9 hp [20.1 kW] (hydro)

PTO pump = Max output @ 540 RPM input: 21 GPM @ 2,000 PSI & 32.1 Hp input

If you ran the engine at about half engine rpm, the 270 PTO rpm would produce about 10.5 GPM.

However since you have a variable splitter, you can obtain any flow you need.

Using your tractor pump, you would have more hyd power if the pump setting is about 2500 psi.

GPM dictates the speed of operation.

 

[Spiros]

Finally finished the variable splitter installation and now my backhoe attachment works as it should. Thank you for the tips and pointers.
There is great depth of knowledge on this site!

 

[J_J]

Well, what or how did you do it.

Pictures, diagrams, explanation, something.