Kubota B6000 Aux Hydraulics

[flangefrog]

The Kubota B6000 is capable of controlling auxiliary single action hydraulics with the same lever used for the rear lift arms. This seems like a pretty clean and simple way of adding aux hydraulics to me. Using an integration block or plumbing more valves inline might be more versatile but also much more complex.

Here are the relevant parts of the operating and service manuals that mention this.

Here are photos so you can see how it works. The hydraulic fluid comes up the small hole on the side of the aluminium housing and into the steel cylinder cap. Usually the aux hydraulics connection has a plug in it, so the fluid is forced back down into the lift arms cylinder. When the two way cock is installed and screwed in, it will block the fluid going down to the lift arms cylinder and force it all to go out the aux connection.


I assume that since the onboard or aux hydraulics will be completely blocked off when the valve is set to control the other one, it will retain its position until you switch back to it.

I can't find any part numbers, photos or more info about the two way cock. Can anyone help? I wonder if one could be machined up after taking the measurements. Or maybe a whole new cylinder cap could be made that was designed to have an off the shelf two way valve added.

 

[TheOldHokie]

The Kubota B6000 is capable of controlling auxiliary single action hydraulics with the same lever used for the rear lift arms. This seems like a pretty clean and simple way of adding aux hydraulics to me. Using an integration block or plumbing more valves inline might be more versatile but also much more complex.

Here are the relevant parts of the operating and service manuals that mention this.
View attachment 71503
View attachment 71502

Here are photos so you can see how it works. The hydraulic fluid comes up the small hole on the side of the aluminium housing and into the steel cylinder cap. Usually the aux hydraulics connection has a plug in it, so the fluid is forced back down into the lift arms cylinder. When the two way cock is installed and screwed in, it will block the fluid going down to the lift arms cylinder and force it all to go out the aux connection.
View attachment 71504 View attachment 71505

I assume that since the onboard or aux hydraulics will be completely blocked off when the valve is set to control the other one, it will retain its position until you switch back to it.

I can't find any part numbers, photos or more info about the two way cock. Can anyone help? I wonder if one could be machined up after taking the measurements. Or maybe a whole new cylinder cap could be made that was designed to have an off the shelf two way valve added.

I have a similar setup on my B7200 which is bit newer than your B6000. On mine opening the valve simply connects the lift cylinder to the external port. It does not lock the 3pt - just the opposite. When you raise the 3pt handle the 3pt comes to the top and stays there forcing pressurized oil out the aux port. In my case I use that supply to feed a log splitter valve and return the oil to the transmission filler.

If you need remotes and can't get that part the simplest solution is to plumb a directional control valve into the pump supply ahead of the 3pt rather than after it. That lets you use the remotes and the 3pt without switching back and forth,

Dan

 

[flangefrog]

That seems like an interesting way of using the aux port with a return. It sounds like you only have a one way valve which would be very easy for me to add, but I think having the 3pt moving at the same time would be a pain if driving a single action auxiliary ram.

Any chance you could take a photo of your valve for me?

I have been looking at the option of plumbing in an extra valve in series but I think the idea of using the built in control valve for both 3pt and aux is nice as it's unlikely I'd need to use both at the same time.

 

[TheOldHokie]

That seems like an interesting way of using the aux port with a return. It sounds like you only have a one way valve which would be very easy for me to add, but I think having the 3pt moving at the same time would be a pain if driving a single action auxiliary ram.

Any chance you could take a photo of your valve for me?

I have been looking at the option of plumbing in an extra valve in series but I think the idea of using the built in control valve for both 3pt and aux is nice as it's unlikely I'd need to use both at the same time.

I am sorry - my memory was faulty. The valve is a simple two position selector similar to yours.

In position one the aux port is disabled and 3pt works normally

In position two the 3pt is disabled and the aux port gets pressure flow out when the 3pt lever is raised. Lowering the lever allows gravity flow in reverse.

I have no use for operating a single acting cylinder so I use it to supply a 3pt log splitter valve which is only in use when the tractor is stationary. To transport the splitter I have to switch back and forth. I find that inconvenient.

I now have the logsplitter on a new L3901 with real remotes which work independent of the 3pt. I find that much more convenient. If I were to go back to the B7200 I would ditch that selector and replumb the remotes off the power beyond on the loader valve like I did on the L3901.

I will get you a picture of the 3pt selector valve tomorrow. It looks nothing like the one in your diagram. Its built into the cap which completely replaces the stock cap. Unfortunately the instructions that came with it are long gone.

Edit: Picture added. Lever is in the "3pt" position. Turn it 90 degrees counterclockwise and its in the AUX position. Female coupler pointing rearward is AUX OUT. Male tip on the transmission filler is AUX RETURN

Dan

 

[flangefrog]

Thanks for the pictures! So are you saying that the 3pt actually does hold position when switching to aux? It looks like the cap on the B7200D is almost exactly the same as the one on the B6000, so I wonder if the cap with the valve would be compatible with it. My use case would be for a small front bucket (not a full FEL) with a single action cylinder for raising it. Just something I'd like to try building.

 

[TheOldHokie]

Thanks for the pictures! So are you saying that the 3pt actually does hold position when switching to aux? It looks like the cap on the B7200D is almost exactly the same as the one on the B6000, so I wonder if the cap with the valve would be compatible with it. My use case would be for a small front bucket (not a full FEL) with a single action cylinder for raising it. Just something I'd like to try building.

The 3pt on this tractor is so bad I cant say if if holds or not. But even if it did this would be a massively inconvenoent way to operate a front bucket. When you switch back to 3pt from AUX the 3pt is going to jump to wherever the control lever is cirrently positioned and thats probably not where it was when you switched to AUX.

In my case the lever is full down when switching to AUX and full up using the splitter. If I dont move it to down before switching back the 3pt will slam to the top.

Adding a valve up front is very easy and will operate much better. Its also probably less than the cost of this option if Kubota is still selling it.

Dan

 

[flangefrog]

It sounds like you may have a different type of lever/valve than I've got on the B6000? On the B6000 the lever has neutral (closed), up and down. So it should be in neutral almost all of the time including when switching over if using a single action aux cylinder.

 

[TheOldHokie]

It sounds like you may have a different type of lever/valve than I've got on the B6000? On the B6000 the lever has neutral (closed), up and down. So it should be in neutral almost all of the time including when switching over if using a single action aux cylinder.

I don't know what your B6000 has but my B7200 3pt works like every AG tractor I have ever operated. The 3pt lift control does not have three discrete positions directly linked to the spool. It is infinitely variable over a range from full down to full up. The position of the lever establishes the "neutral" position for the lift which is defined in terms of lift height. If you change the lever position you establish a new neutral position for the lift. Internal linkages in the system will try to establish that height by shifting the spool as needed to raise or lower the lift to match the position selected by the lift control lever.

Dan

 

[flangefrog]

It's actually been a while since I used a tractor but I think I remember David Browns being like that. There must be some sort of closed-loop feedback? The B6000 has a valve more like a FEL or backhoe etc. It only has three positions. You can keep it in up or down but it does spring back to the centre with a little push. in up, it lets fluid flow from the pump to the cylinder, in down it lets fluid return from the cylinder back into the transmission case and in the centre it prevents any flow from the cylinder.

 

[OldBota6000]

Hello guys I’m new on here and this seemed relevant so here goes. I have a B6000 in really decent shape and I wanted to plumb on a plow blade with a lift and lower option ( currently manual lifting lol ) the only problem is my aux hyd output is a single fitting and I believe the hydraulic cylinder I have is a small 2-stage either that or it’s input and return?? I’m pretty new to this type of thing so do I have any options with this or do I need a different single action hyd cylinder? There is also no return line on the transmission fill cap, and don’t worry I’ve already replaced that nasty old quick release any help would be greatly appreciated and thank you.

 

[TheOldHokie]

Hello guys I’m new on here and this seemed relevant so here goes. I have a B6000 in really decent shape and I wanted to plumb on a plow blade with a lift and lower option ( currently manual lifting lol ) the only problem is my aux hyd output is a single fitting and I believe the hydraulic cylinder I have is a small 2-stage either that or it’s input and return?? I’m pretty new to this type of thing so do I have any options with this or do I need a different single action hyd cylinder? There is also no return line on the transmission fill cap, and don’t worry I’ve already replaced that nasty old quick release any help would be greatly appreciated and thank you. View attachment 73030 View attachment 73031

Looking at the picture it appears the quick coupler is on the side of the hydrualic lift cover. Does your operators manual provide any insight into how it works?

Not knowing the exact operation of the outlet makes things difficult but I will walk out on a thin limb and assume it is designed to operate a single acting cylinder using the tractors hydraulic lift control lever. There may be a valve or lever for enabling its operation. If that is correct you are pretty much good to go.

1. Your cylinder is double acting but you can use it in single acting mode by putting a breather plug in the port on the rod end.
2. Replace the chain with the cylinder such that it raises the plow when it extends.
3. Connect the base end port on the cylinder to your hydraulic outlet.

At this point you need to perform whatever magic it takes to enable the operation of the hydraulic outlet. With the outlet enabled you should be able to raise and lower the plow using the hydraulic control lever.

Dan

 

[OldBota6000]

Looking at the picture it appears the quick coupler is on the side of the hydrualic lift cover. Does your operators manual provide any insight into how it works?

Not knowing the exact operation of the outlet makes things difficult but I will walk out on a thin limb and assume it is designed to operate a single acting cylinder using the tractors hydraulic lift control lever. There may be a valve or lever for enabling its operation. If that is correct you are pretty much good to go.

1. Your cylinder is double acting but you can use it in single acting mode by putting a breather plug in the port on the rod end.
2. Replace the chain with the cylinder such that it raises the plow when it extends.
3. Connect the base end port on the cylinder to your hydraulic outlet.

At this point you need to perform whatever magic it takes to enable the operation of the hydraulic outlet. With the outlet enabled you should be able to raise and lower the plow using the hydraulic control lever.

Dan

Thanks Dan thats kind of the conclusion I came to as well pretty sure it is always active on this unit as with the 3PH. So if my thought process is correct on this, pulling back on the 3PH/Hydra Sickle lever should energize the line and cylinder and pushing the lever forward will de-energize allowing the cylinder ram to retract under the weight of the plow is that correct?

 

[TheOldHokie]

Thanks Dan thats kind of the conclusion I came to as well pretty sure it is always active on this unit as with the 3PH. So if my thought process is correct on this, pulling back on the 3PH/Hydra Sickle lever should energize the line and cylinder and pushing the lever forward will de-energize allowing the cylinder ram to retract under the weight of the plow is that correct?

You are asking me to get even farther out on that limb. If it is "always active" it would be in parallel with the 3pt cylinder and you would have a hydraulic see-saw - the lighter load raises and the heavier load stalls. That is my guess but without some documentation on how that option works its just a guess.

Dan

 

[Vigo]

On my b6100 there is a T-handle lever right next to that outlet port that switches back and forth between 3pt and external port. I would guess the see-saw problem Dan mentioned is the reason why all of the selector valve styles are either/or but not 'both'.

As for the transmission fill plug return fitting, im sure someone sold it at some point but you are probably best off either fixing a fitting into your stock fill cap (mine is plastic, would be easy) or measuring its thread diameter/pitch and buying something. Either way, it's gonna be substantially 'YOU have to figure it out'.

 

[TheOldHokie]

You are asking me to get even farther out on that limb. If its "always active" it would be in parallel with the 3pt hitch. In that case the 3pt will come up and go down along with the plow. ItThat is my guess but without some documentation on how that option works its just a guess.

Dan

On my b6100 there is a T-handle lever right next to that outlet port that switches back and forth between 3pt and external port. I would guess the see-saw problem Dan mentioned is the reason why all of the selector valve styles are either/or but not 'both'.

As for the transmission fill plug return fitting, im sure someone sold it at some point but you are probably best off either fixing a fitting into your stock fill cap (mine is plastic, would be easy) or measuring its thread diameter/pitch and buying something. Either way, it's gonna be substantially 'YOU have to figure it out'.

I would expect there is a selector of some sort. On the old Fords you had to chain the lift arms down - not very convenient.

An adapter for the filler should be EZPZ. I will guess its just a BSPP port.

Dan