Kubota M108 3PH priority

[rolandjeff]

Hi,

We bought a Kubota M108 last year to use as our main seeding tractor. We grow row crop vegetables and were looking for a small light tractor that could handle our seeder. The tractor is great and works well. The only issue we have run into is that our seeder uses a hydraulic motor to run the fan for the seeder. When we get to the end of the row and try to raise the 3PH, it will not lift until we disengage the hydraulic motor. Any tractor we have used before provides the 3PH with priority over the remotes. Is there anyway to change this somehow. We have talked with our local dealer and they tell us that there is nothing we can do. This is frustrating because it knocks all the seed off our discs at the end of the row.

Thanks for any help.

 

[bigdeano]

It looks like your tractor has a large hydraulic flow, so you could use a priority flow divider to split the flow so both the 3ph and the remotes will work at the same time. If you use an adjustable one you can set the flow to your liking. Surplus Center has some.

 

[rolandjeff]

It looks like your tractor has a large hydraulic flow, so you could use a priority flow divider to split the flow so both the 3ph and the remotes will work at the same time. If you use an adjustable one you can set the flow to your liking. Surplus Center has some.

Thank you. I will look into this.

 

[Dave M7040]

Hi,

We bought a Kubota M108 last year to use as our main seeding tractor. We grow row crop vegetables and were looking for a small light tractor that could handle our seeder. The tractor is great and works well. The only issue we have run into is that our seeder uses a hydraulic motor to run the fan for the seeder. When we get to the end of the row and try to raise the 3PH, it will not lift until we disengage the hydraulic motor. Any tractor we have used before provides the 3PH with priority over the remotes. Is there anyway to change this somehow. We have talked with our local dealer and they tell us that there is nothing we can do. This is frustrating because it knocks all the seed off our discs at the end of the row.

Thanks for any help.

The flow divider is certainly an option. The challenge is getting to the lines to install the flow divider between the 3 pt hitch and existing rear remotes.

Your tractor has an open center hydraulic system so the first control valve closest to the pump output gets the flow ( which now is the rear remote feeding the motor) and other items downstream have to wait.

Unlike older tractors more, and more hydraulic valves are internal to the transmission so altering systems is challenging. I expect the rear remotes are fed internally in the same area of the transmission as is the 3 pt hitch.

My experience is the hydraulic flow on larger Kubotas goes to the steering, then FEL and next, using a power beyond feature of the FEL, to the rear of the tractor.

If there was a new flow divider on the power beyond outlet of the FEL, then part of the flow would constantly be going to the 3 pt and factory rear remotes and the other part of the flow divider could go to new quick couplers on the rear of the tractor which are just conveniently located but otherwise independent from the existing rear remotes. There would be a new control valve
feeding the new rear remotes so you can control the hydraulic motor.

If this explanation is not clear enough please ask some questions and I will expand my logic further.

Dave M7040

 

[ovrszd]

Dave nailed it.

 

[rolandjeff]

The flow divider is certainly an option. The challenge is getting to the lines to install the flow divider between the 3 pt hitch and existing rear remotes.

Your tractor has an open center hydraulic system so the first control valve closest to the pump output gets the flow ( which now is the rear remote feeding the motor) and other items downstream have to wait.

Unlike older tractors more, and more hydraulic valves are internal to the transmission so altering systems is challenging. I expect the rear remotes are fed internally in the same area of the transmission as is the 3 pt hitch.

My experience is the hydraulic flow on larger Kubotas goes to the steering, then FEL and next, using a power beyond feature of the FEL, to the rear of the tractor.

If there was a new flow divider on the power beyond outlet of the FEL, then part of the flow would constantly be going to the 3 pt and factory rear remotes and the other part of the flow divider could go to new quick couplers on the rear of the tractor which are just conveniently located but otherwise independent from the existing rear remotes. There would be a new control valve
feeding the new rear remotes so you can control the hydraulic motor.

If this explanation is not clear enough please ask some questions and I will expand my logic further.

Dave M7040

I just had a look and it looks like there is a line coming off the pump going to the rear remotes. We don't have a FEL. So we could put a divider right before it goes into the rear remotes. Have the one line set to go to the remotes and 3PH and the other one feeding the motor?
Now if we have 17GPM supply and i send 12GPM to the remotes and the rest to the motor, will we only ever have 12GPM available for the remotes, or if we are not running the motor would we get the oil its not using? My understanding is that the divider will split the flow, but what happens when one side isn't being used?

What about using a restrictor before the hydraulic motor?

Thanks for your help Dave.

 

[oldnslo]

Roland,
How much flow does the hydraulic motor on your planter require? Reason for asking is that using a priority flow control will reduce the flow to the motor which might cause the air planter to not generate enough blower pressure to to operate correctly.

 

[rolandjeff]

I am estimating about 6-7 GPM. I should know more accurately when we are able to hook it up and run it so i can count count the RPM we are using.

 

[bigdeano]

If you have the controlled flow port feeding the motor you can adjust the flow to the motor from zero to your max pump flow. What's left over would go out the excess flow port to the remotes and 3PH. If you're not using the motor, just set the flow control to zero and all the flow will go to the remotes and 3PH.

 

[rolandjeff]

If you have the controlled flow port feeding the motor you can adjust the flow to the motor from zero to your max pump flow. What's left over would go out the excess flow port to the remotes and 3PH. If you're not using the motor, just set the flow control to zero and all the flow will go to the remotes and 3PH.

So could i put something like this before the remote valves then? I am guessing i would need a pressure relief coming out the EF port then?

3/4 NPT Hydraulic Flow Control Valve w/Relief RDRS175-3 | Prince Mfg | Brands | www.surpluscenter.com