Hydraulic motor driven centrifugal pump

R&S Fence · Feb 4, 2010

I have a 2003 Kubota Grand L3010 HST. I have plumbed a 3 spool Metro valve for a T&T, which is best money spent. Anyways, I also have a 3-point sprayer w\ 16' boom which used to have a PTO Hypro Silver Cast roller pump.
In order to run wettable powders and to cut down on tractor RPMs, I switched to an Ace hydraulic motor driven centrifugal pump. Motor requires 3gpm max flow. Connection for hyd. motor was made on middle spool. Hyd. motor out line goes to tank. Now when the hyd. motor is running,3-point won't lift. Not sure of T&T. FEL still operates, and when it does, you can hear hyd. motor speed up. Question is, would a flow divider or priority valve restore 3-point functions. Also, if it would where in plumbing would it go? Talking to a mechanic, he said "Might be able to use FEL valve since the FEL comes off for spraying". Hyd pump capacity 7gpm.

aczlan · Feb 4, 2010

What it happening when nothing is on is that fluid leaves the pump, passes through the FEL controls, through your valve block, through the 3pt control block and into the transmission.
When you turn on the pump, the fluid leaves the pump, passes through the FEL controls, through your valve block into the motor, out of the motor, back into the valve block and into the transmission (bypassing the 3pt controls).

If you were to measure the RPMS of the pump in your sprayer you would probably find that they drop if you lift the FEL from the ground to max height. This is because a open center hydraulic system in your tractor is a sequential system and the first thing the sequence gets all the pressure, the others get what is left.

Aaron Z

dfkrug · Feb 5, 2010

R&S Fence said:
"Might be able to use FEL valve since the FEL comes off for spraying".

Since your tractor has just the one implement pump, any valve upstream of
your AUX valves will cutoff the flow to your hydraulic motor. That means
that if you operate either FEL valve, the motor will stop. In the same
way, your AUX valve cuts off all flow to the 3-pt. The only way to make
this work (beyond the complexity of a flow divider and new valve) is to
turn off the hyd motor, operate the 3-pt, then turn the motor back on.

You CAN probably lower your 3-pt while the hyd motor is running....just
can't raise it.

R&S Fence · Feb 5, 2010

hooked it up today to see what all worked with motor running. FEL and T&T all worked if feathered, slowed motor down and dropped pressure slightly. Since FEL will be off for spraying, does'nt matter. The 3-pt still won't raise unless I slow motor down by feathering the hyd motor valve. Then it works fine. Still, would a splitter or flow divider fix that? Also Ace BAC-75 hyd204 requires min. 4gpm. Also hydraulic fluid temp, what should be the max temperature for the Kubota L3010 HST.

Thanks for the replies

J_J · Feb 6, 2010

Have you considered this kind of valve. This is a 12 v priority valve. In the normal mode, all the flow goes out one port, and when you want priority flow, which in this valve is 1 gal, flip a switch and you have 1 GPM for the 3-pi. So, all fluid would go to the motor until you wanted to use the 3-pt, Since the orifice is fixed for 1 GPM, the motor will slow a little when using the 3-pt.

There are also fixed flow dividers to divide the flow into equal or unequal circuits . There are also manual push/pull valves that can be used.

https://www.surpluscenter.com/item.asp?UID=3516020606152978&item=9-4017&catname=hydraulic

R&S Fence · Mar 1, 2010

Ok, just installed Brand flow control valve model FC51. 8 GPM input. I thought I could let 4GPM go to HYD motor (min. required) and the rest, being pressurized go out the excess port to the "in" port of spool valve and the continue to 3pt. circuit. It still is not letting 3pt; or TNT work unless I turn down flow to 3.5GPM, then motor slows down some. Any suggestions?

kennyd · Mar 1, 2010

R&S Fence said:
Ok, just installed Brand flow control valve model FC51. 8 GPM input. I thought I could let 4GPM go to HYD motor (min. required) and the rest, being pressurized go out the excess port to the "in" port of spool valve and the continue to 3pt. circuit. It still is not letting 3pt; or TNT work unless I turn down flow to 3.5GPM, then motor slows down some. Any suggestions?

So you have the flow valve hooked up after the remote valve? Can you take or draw a picture of the hookup?

The way I see it, a priority/flow valve must be in the main flow (the PB line in this case), with 1/2 going to your motor and 1/2 going to your 3PH. Putting it after the valve does nothing-because the remote valve is stealing the flow from the IN port and directing it through the spool, then to the OUT (tank) port leaving nothing for the 3PH.