3-Point Hitch Kubota B3000 crazy hydraulics

[B3000]

I have a hydraulic spray pump connected to one of my remotes. It works perfect. The problem is that while the spray pump is running, my 3 point hitch will not go up or down. Is there a fix for this? I can't use the pump and operate my hitch at the same time. What gives?

 

[easygo]

Try to operate the loader and raise the 3pt hitch at the same time. It does not work on my tractor. There must be physics involved but I don't know the real reason.

 

[Chilly807]

This is normal behaviour for most tractors. The power beyond system allows flow to valves downstream (such as your 3-point valve) as long as there is no demand upstream (such as the FEL or remote valves).

When you operate your sprayer, all of the hydraulic flow is diverted to it, with none left for the 3-point, which is always the last valve in the system. If you can feather the remote valve while raising or lowering the hitch, you may get some response, but it will be slow if at all.

Irritating, but the good news is there is nothing wrong with your tractor. I think you should be able to lower the hitch, but not raise it.

Sean

 

[B3000]

So if nothing can be done to "correct" my problem how can I connect my spray pump to the mid hydraulic block (where a FEL would normally connect)?

How, exactly, would this need to be plumbed? It would need some sort of valve to turn the pump on and off.

I could get the tapped block cover plate from my dealer and then what do I need...?

 

[Verticaltrx]

So if nothing can be done to "correct" my problem how can I connect my spray pump to the mid hydraulic block (where a FEL would normally connect)?

How, exactly, would this need to be plumbed? It would need some sort of valve to turn the pump on and off.

I could get the tapped block cover plate from my dealer and then what do I need...?

No matter where you connect it it will have the same problem. As Chilly said the 3pt hitch is the last valve in the circuit, so if ANY other valves are being used (loader or remotes) the 3pt hitch won't have any oil flow.

I'd look into a pto drive pump for the sprayer if possible.

 

[B3000]

Chilly you are correct, hitch will lower just not raise while the remotes are in use.

Looks like if I could somehow get just the small amount of constant metered flow to the spray pump, then the hitch should still function. As you can tell, I not well versed in hydraulics. Is it the open center system that is my problem?

 

[kuboman]

Chilly you are correct, hitch will lower just not raise while the remotes are in use.

Looks like if I could somehow get just the small amount of constant metered flow to the spray pump, then the hitch should still function. As you can tell, I not well versed in hydraulics. Is it the open center system that is my problem?

If you plug into one of the loader remotes your system should work. You would need to hold the loader valve open somehow, tarp strap maybe.

 

[B3000]

There is no loader on this tractor. That's want I'm wondering if I can operate the spray pump through some type of valve attached to the loader valve port on the side of the tractor. Can I do this and the hitch work at the same time?

 

[kuboman]

There is no loader on this tractor. That's want I'm wondering if I can operate the spray pump through some type of valve attached to the loader valve port on the side of the tractor. Can I do this and the hitch work at the same time?

As long as your sprayer motor does not use all the flow you should still be able to run you 3pt. I can raise my 3pt at the same time I use the loader so you should be able to do the same.

 

[rambler]

What is the rated output of your tractor hydraulics?

What is the rated need of the hyd sprayer pump?

I think you will find the pump is using all - and maybe wants more - oil flow than your tractor can deliver.

It is like flushing a toilet & taking a shower at the same time - only one device gets the most flow of water.

In your case you are not really hurting anything(*), but the pump is using up all the hyd flow available. While the pump ios running, it is using all your hyd capacity, and nothing is left for the 3pt lift.

You have to choose which hyd device you want to work at any one time - the pump, or the 3pt. To make the 3pt raise, you'll need to flip off the pump for a short while.

There are flow dividers, something could be rigged up to split your hyd flow to always have some flow to the spray pump and some flow to the 3pt. BUT it does not sound like you have enough hyd flow to bother trying with this, it will not work if you don't have enough hyd flow from your tractor to start with.

What tractor, what hyd pump does it have if there are several options, and what sprayer pump are you using, good hyd experts here could work out the flow you have, ther flow the pump needs, and if there is any fixes available.

In general, it sounds like the sprayer pump is using up everything available, so the only fix is to go to a pto sprayer pump, or turn off the hyd pump when you need to use the 3pt.

(*)If the sprayer pump is using a lot of oil and working hard on a tractor with a small oil supply, if run for a long time it could heat up the oil and cause foaming, heating, and cause some problems along the way.

--->Paul

 

[CHDinCT]

Depending on what he wants to spend to fix this issue, I agree with Verticaltrx that buying a PTO driven hydraulic pump and tank would be the ideal fix. This adds a separate, dedicated pump for the sprayer that's run off of the rear PTO. Might be tricky figuring out where to mount the hydraulic oil resevoir though.

Something like this for the pump depending on the GPM required to run the sprayer.
Surplus Center - 3.6 CU IN PRINCE HC-PTO-7A PTO PUMP 540 RPM

And one of these tanks again depending on how much oil the sprayer requires. A larger reservoir will allow the oil to run cooler. Surplus Center

If the OP is serious for this option, I would suggest he start a thread in the hydraulics section to get help with spec's and how to hook it all up.

 

[B3000]

Turning off the spray pump to use the 3pt hitch is not an option in this case. It's just not practical.

The spray pump needs a maximum of 4 gpm. It has its own needle valve bypass to set its operating speed. The B3000 tractor hydraulic system puts out 9.1 gpm.

That should be enough excess if I knew how to plumb in the correct control valve for the sprayer pump and not have it connected to the remotes.

Maybe this will never work, but its fun to try and figure it out!

 

[CHDinCT]

Turning off the spray pump to use the 3pt hitch is not an option in this case. It's just not practical.

The spray pump needs a maximum of 4 gpm. It has its own needle valve bypass to set its operating speed. The B3000 tractor hydraulic system puts out 9.1 gpm.

That should be enough excess if I knew how to plumb in the correct control valve for the sprayer pump and not have it connected to the remotes.

Maybe this will never work, but its fun to try and figure it out!

Just checked the Kubota web site and of your 9.1 GPM total flow, 3.9 GPM is dedicated to power steering with the remaining 5.2 available for all hydraulic functions. That would mean there'd be 1.2 GPM theoretically available for other functions besides the sprayer. But, I think once you send fluid to your sprayer, any excess may just go back to the tank, unless like stated above, you feather the valve. Don't know enough more to give you any advice on hydraulic solutions (other than the separate PTO pump) but someone who frequents the hydraulics forum above might. Good luck.

 

[J_J]

There are flow dividers to provide two outputs. Some are priority, and other dividers are equal flow for both outputs.

For instance, your sprayer needs 2 GPM, and your tractor pump puts out 6 GPM. Then since the sprayer will always get the 2 GPM priority flow, the other 4 GPM is available for the other hyd on the tractor.

If you decrease engine rpm, you will decrease the hyd for the other tractor functions.

You could also get a 12V pump for the sprayer. I have one of those pumps mounted on a 25 gal tank .

 

[aczlan]

If you put something like Surplus Center - 3/8" NPT 30 GPM ADJ PRIORITY DIVIDER VALVE RD537 inline before the 3 point valve, you can have 4gpm go to your sprayer through the priority port and the rest going to the 3 point valve.

Aaron Z