Rear Remote Kubota L39

[jmanatee2]

I want to add rear remote hydraulics to my Kubota L39 to run a thumb.

I am trying to grasp the addition of a valve to the system. From what I have read I want a 2way valve with power beyond.

There will be 5 hoses that connect to this.

2 will go to the hydraulic cylinder
1 will be the high pressure line that I disconnect from the backhoes spool
1 (power beyond port) will connect to the backhoes spool valve.
1 will tee into the return to reservoir line.

Does this sound correct?

Also the Kubota L39 has (I think) has 11.9 gpm feeding the backhoe. Does this mean the valve can be anything greater then that? 20 gpm would work?

Also I am not sure what the standard pressure is for this tractor but would 3000 PSI valve be ok? 2500psi, 2000psi?

finally is there a standard fitting size for the quick connect couplers used by SSQA stuff?

Anyone know what the fittings are for the kubota connection? Pipe, Compression, Flare etc.. and the size of the connectors?

Any suggestion on where to buy the components would be appreciated.

If anyone can point out other information please let me know

 

[kennyd]

I want to add rear remote hydraulics to my Kubota L39 to run a thumb.

I am trying to grasp the addition of a valve to the system. From what I have read I want a 2way valve with power beyond.

There will be 5 hoses that connect to this.

2 will go to the hydraulic cylinder
1 will be the high pressure line that I disconnect from the backhoes spool
1 (power beyond port) will connect to the backhoes spool valve.
1 will tee into the return to reservoir line.

Does this sound correct?

Yes, that is 100% correct. You can use 1/4" hoses for the thumb cylinder, but all others should be at least 3/8"-or the same size that feeds the hoe now.

Also the Kubota L39 has (I think) has 11.9 gpm feeding the backhoe. Does this mean the valve can be anything greater then that? 20 gpm would work?

Also I am not sure what the standard pressure is for this tractor but would 3000 PSI valve be ok? 2500psi, 2000psi?

Correct again for both questions.

finally is there a standard fitting size for the quick connect couplers used by SSQA stuff?

SSQA stuff usually uses "flat face" couplers.

Anyone know what the fittings are for the kubota connection? Pipe, Compression, Flare etc.. and the size of the connectors?

Can't help exactly, but they are probably NPT, JIC or ORB. You will have to measure to find the size: Fluid Port Size Charts > Discount Hydraulic Hose.com

Any suggestion on where to buy the components would be appreciated.

DHH (linked above) and the Surplus Center.

 

[jmanatee2]

Can anyone recommend a valve? I can find many valves I think are correct but I don't want to order the wrong one.

I also read somewhere that most valves that can switch from open to close center can also have a power beyond plug or sleeve installed, Is that true?

 

[J_J]

Yes, it is true.

This valve is an 8 GPM valve.


https://www.surpluscenter.com/item.asp?item=9-7861&catname=hydraulic

 

[jmanatee2]

Yes, it is true.

This valve is an 8 GPM valve.


https://www.surpluscenter.com/item.asp?item=9-7861&catname=hydraulic

I think the Kubota L39 has a two pumps feeding the backhoe, one 11gpm feeding the boom crowd and dipper, and the second pump supplying swing with 6gpm.

I will look more closely at that pump.

Thank you.

 

[MarkV]

In case you don't know, Kubota makes a hydraulic kit with a foot operated control to run a hydraulic thumb. Great set up but not cheap.

MarkV

 

[kennyd]

Can anyone recommend a valve? I can find many valves I think are correct but I don't want to order the wrong one.

I also read somewhere that most valves that can switch from open to close center can also have a power beyond plug or sleeve installed, Is that true?

Here is a 14 GPM valve: Surplus Center - 1 SPOOL 14 GPM PRINCE WVS11B5C1 DA VALVE

If your a good fabricator you could make it controlled with a foot pedal.

 

[Stonehaller]

I think the Kubota L39 has a two pumps feeding the backhoe, one 11gpm feeding the boom crowd and dipper, and the second pump supplying swing with 6gpm.

I connect to the swing pump to run remotes for my 3 point top link and snowblower rotate. Relief pressure for the swing pump is 2500 psi verse 2750 for the main pump. You could use the 8 gpm valve that J_J recommended with the swing pump, just be sure to the power beyond plug for it.

 

[J_J]

jmanatee2,

Here is another idea for you. If you were to put a selector valve in the stabilizer leg circuit, you could select which function you want to use, stabilizer legs set, or BH thumb. Once you set the stabilizer legs, flip the switch on the selector valve, and the stabilizer hydraulics go to the thumb. and use the stabilizer lever to operate the thumb.

With no power to the solenoid valve, the stabilizer legs work normally. Flip a switch and power the solenoid on, and the hydraulic flow now go to the thumb for as long as you have power on the solenoid. The stabilizer lever now operates the thumb.

https://www.surpluscenter.com/item.asp?item=9-5117-A&catname=hydraulic

 

[jmanatee2]

jmanatee2,

Here is another idea for you. If you were to put a selector valve in the stabilizer circuit, you could select which function you want to use, stabilizer legs set, or thumb. . Once you set the stabilizer legs, flip the switch on the selector valve, and the stabilizer hyds go to the thumb. and use the stabilizer lever to operate the thumb.

With no power to the solenoid valve, the stabilizer legs work normally. Flip a switch and power the solenoid on, and the hydraulic flow now go to the thumb for as long as you have power on the solenoid. The stabilizer lever now operates the thumb.

Thats a neat idea. I take it after setting the stabilizer, then changing the selector switch the stabilizer would hold the position I left it in.

Are there two line selectors? I take it there would be six connectors A + B from spool A + B to stabilizer and A + B to thumb.

On Edit: I didn't see your link, I just looked at that item That switches with 12v

 

[J_J]

Yes, 12v and six hoses, Here are the instructions.

https://www.surpluscenter.com/Instruct/I9-5117-A.pdf

There are other selector valves that will handle more GPM's, but of course the price goes up.

You could mount a switch handle on that lever for operating the thumb.

You could also rig it so the thumb is on and the stabilizer is momentary.

 

[Telstar2112]

I know this is an old thread but I like this idea. Seems pretty simple. I plan to add a thumb to my L35. Using this setup for the thumb do I need to worry about pressure relief? Could the curl of the backhoe bucket against the thumb cause too much pressure for this circuit?

Also, is there a manual valve version of this so I wouldn't even have to run wires?

To the original poster, what did you end up doing and how did it work out?

 

[dondc]

My L35 has a foot pedal to operate the thumb and a relief valve on the thumb hydraulic line. I believe that the foot pedal is a Kubota stock item. Unfortunately, I don't know enough about hydraulics to tell you how to plumb it in to the curl line but I am sure that if JJ chimes in that he can help you. There are no electrical lines on my setup.

 

[J_J]

I know this is an old thread but I like this idea. Seems pretty simple. I plan to add a thumb to my L35. Using this setup for the thumb do I need to worry about pressure relief? Could the curl of the backhoe bucket against the thumb cause too much pressure for this circuit?

Also, is there a manual valve version of this so I wouldn't even have to run wires?

To the original poster, what did you end up doing and how did it work out?

Do you have a valve to operate the thumb?

Just match the valve GPM with BH supply GPM

In order to protect the thumb cyl, you need a relief across the thumb cyl.

 

[Telstar2112]

No, I don't have a valve yet. What I was saying was that I liked your idea of using one of the stabilizer valves and adding the solenoid valve you suggested (or a manual version of it). To me this seems simpler than a new valve and worrying about power beyond and the return and all that, but maybe I am mistaken? If I were to do this, using the stabilizer valve and the solenoid valve would I still need to worry about relief or is that already built into the stabilizer valve?

 

[J_J]

The BH should have it's own relief while using the cyl.

When the valve spool goes to neutral, flow is blocked , so you will need work port relief for the thumb.

With a manual valve, you need the PB unless it is the last valve in the series path.

Hyd subplates port are all high pressure.

Either way, you need the relief valve across the cyl.

Some valves have work ports reliefs.

 

[Telstar2112]

J_J, with that 14gpm valve you suggested, it says I need an additional part, the power beyond sleeve, to have power beyond or closed center. It appears that my backhoe valve bank does not have any power beyond port so I would need to add this valve in before the main valve bank. Forgive my lack of knowlege, but for a thumb I believe I want a closed center, correct?. I would also need the power beyond to feed the main valve bank. So will this valve work, and do I need to buy two sleeves to have both power beyond as well as closed center? This is all new to me so any help is greatly appreciated.

Also, do you see any problem adding this in before my main valve bank? I guess the pressure would run through the valve to the power beyond and I would just have to tee together the return.

I also just noticed that the page for the power beyond sleeve states "Power Beyond:
Allows oil flow to a down-stream valve while first valve is in neutral position. Outlet port of first valve must be plumbed directly to reservoir." I am not sure exactly what this means, I guess while I was moving the thumb all my other functions would be dead?

I just want to make sure to order the right stuff, I see Kubota sells a kit which I just priced at $1750 from the dealer...way too steep! (I wondered if maybe it included the thumb, but no!)

Thanks,
Steve.

 

[J_J]

You don't need closed center for anything.

You need the PB sleeve to connect to another valve downstream.

If you are using a BH right now, and it is working good, then it must be sending high pressure downstream to the 3pt.

A thumb can use hyd from several different sources.

A valve upstream of the BH with PB.

A diverter valve using one of the stabilizer spools. Default would be stabilizer, and when you select the button on the stabilizer lever , the thumb would operate. You need a relief valve across the thumb cyl.

A true 3rd function using a solenoid valve upstream using a thumb switch on one of the levers.

You should be able to do a thumb control for about $200.

There are certain situations where you may lose hyd flow downstream.

During the time the 3rd function is being used, the flow downstream is coming from the hyd cyl or hyd motor the 3rd function valve is controlling.

If you are using a lever valve for the thumb, and only use half lever, you still have about half flow for downstream use.

All OUT ports should go to tank.

 

[Telstar2112]

Thanks J_J and all. So I ordered everything I need, I think, including 14gpm valve, pb spool, lots of extra fittings, and 4 hoses for under $275. Much better than $1,750! Once I get it all figured out an working I'll post part numbers for what I used and how it worked out.

 

[Telstar2112]

Darn, I got notification that the power beyond sleeve for that 14GPM DA valve is backordered. I was going to put this valve prior to the main bank on the backhoe. I really wanted to get this thumb installed to play around with it while I am off from work this week. Does anyone know any workaround? I know this is probably a newbie question, but why can't a valve like this just be T'eed into both the pressure and return lines going to the main valve bank on the backhoe? Would this work?

Thanks,
Steve.