Adding Frame Mt BH. How to add Hydraulics ?

MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
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Hello Orange People,
So I have a L3430 Grand and picked up a damn near new TYM/Rural King 8.5 frame mount backhoe for real cheap. I designed and built an integrated frame attachment for the tractor so now onto the hydraulics. I have the LA723 loader and no rear remotes. I was going to use a PTO pump but due to the recessed pocket where the PTO shaft comes out the typical pump will not fit. I thought about using a splined 1-3/8 extension but adding slop and load leverage seems to keep me up at nights. So I'm looking to see how best to use the factory system and tap into it to gain the rear lines or another route to get the hoe in motion. Please let me know if you may have any advice or references that I can seek. I have searched many threads and there seems to be several variations in the Kubota Kubota letter hydraulic systems and even nuances within the same L series.
Thanks and have a great day,
Wayne
 

je1279

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LX2610 w/ 60" MMM, LP 72" FB, Wicked Tooth Bar & 55" Grapple and Woods 60" BB
Dec 6, 2020
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Upstate NY
Can you use the power beyond loop to provide hydraulics to the backhoe? There should be an existing hose you can replace to run hydraulic fluid to and from the backhoe. When the backhoe is off, you would simply connect the hoses to complete the loop.
 
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MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
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It looks like the block under the right foot has connections in each port so I'm not sure where to tie into the beyond port. Is there an add on block or tee into that line? Would there be any changes in the operation of the loader with the hoe connected or changes to the back hoe holding position during movements of the loader. Or if I understand you correctly all those questions are null due to the controls holding fluid in a locked position.
 

je1279

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LX2610 w/ 60" MMM, LP 72" FB, Wicked Tooth Bar & 55" Grapple and Woods 60" BB
Dec 6, 2020
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Upstate NY
It looks like the block under the right foot has connections in each port so I'm not sure where to tie into the beyond port. Is there an add on block or tee into that line? Would there be any changes in the operation of the loader with the hoe connected or changes to the back hoe holding position during movements of the loader. Or if I understand you correctly all those questions are null due to the controls holding fluid in a locked position.
I'm going to defer to folks more familiar with the L series than I but I believe there is a BY port on the loader valve that connects to the BY port on the manifold block under your right foot. That hose can be removed and new hoses can be routed to go from the BY port on the loader valve to the backhoe and then the return line would connect to the BY port on the manifold block. The video below isnt for your model but it should give you an idea how to do it. Also, tapping into the power beyond loop will not impact the loader functionality. Hopefully, other L owners with backhoes will chime in with anything I may have missed.


 
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MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
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Thanks greatly for the information and the video was very helpful. I'll look at my control valve and see how close it is to the one you sent.
 
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TheOldHokie

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L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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Myersville, MD
I'm going to defer to folks more familiar with the L series than I but I believe there is a BY port on the loader valve that connects to the block under your right foot. That hose can be removed and new hoses can be routed to go from the BY port on the loader valve to the backhoe and then the return line would connect to the same tank port on the block. The video below isnt for your model but it should give you an idea how to do it. Also, since power beyond is a constant flow on its own loop, it will not impact the loader functionality. Hopefully, other L owners with backhoes will chime in with anything I may have missed.

Thats good up to the point of the tank return on the backhoe. Presumably that valve is also power beyond so there are three hose connections as follows:

1) Disconnect PB hose on loader from hydraulic manifold on tractor and reroute to pressure in on back hoe valve. Probably needs a longer hose.

2) Now connect PB port on backhoe valve to open port on hydraulic manifold with second hose.

3) Disconnect tank return hose on loader valve from hhdraulic manifold and install a tee in manifold. Reconnect loader return hose to tee and run a third hose from tank return on back hoe valve to that same tee.

Alternatively leave the loader return as is and run the back hoe return hose to the tank filler or any other direct to tank connection you can find.

Dan
 

kubotafreak

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GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
Sep 20, 2018
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Take the pb port from loader valve to feed backhoe. Then the return to backhoe to this control valve cover T port (140).(use a orb to jic 90) There are 4 different loader valves for that loader, otherwise I would post the pb port.
 

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MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
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Thanks Kubotafreak,
I like this approach. Seems straight forward. Is there any need to connect the loop if I don't have the BH on the tractor or an issue of dead heading the system? This looks like the way my rear remote is configured on my other tractor but feeds a remote self centering control valve designed to operate the hyd center link.
Wayne
 

TheOldHokie

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L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
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Myersville, MD
Thanks Kubotafreak,
I like this approach. Seems straight forward. Is there any need to connect the loop if I don't have the BH on the tractor or an issue of dead heading the system? This looks like the way my rear remote is configured on my other tractor but feeds a remote self centering control valve designed to operate the hyd center link.
Wayne

Before you connect anything you need to determine exactly how the valve on the backhoe operates. If it has a P, PB, and T port you need all three connected to the appropriate points on the tractor's system.

P = pressure IN to the valve
T = tank return to the reservoir
PB = pressure OUT to next valve in the series

Did you get the manual with the backhoe? I think that is required reading before blindly hooking things up.

Dan
 
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MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
25
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21102
Hello Dan,
I did get the manual and read through it but honestly its not detailed in regards to the hydraulics, only stating to connect the two hyd lines to the tractors hdy system. With only the two lines I think its the P and T lines. Both are 1/2 npt male so I'll be getting the quick connects to match the ones I will be installing on the tractor.
 

MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
25
12
3
21102
Take the pb port from loader valve to feed backhoe. Then the return to backhoe to this control valve cover T port (140).(use a orb to jic 90) There are 4 different loader valves for that loader, otherwise I would post the pb port.
Any idea what the thread size is for the fitting where it fits into the tractor? I'm going to order a fitting but the tractor is 30 miles away. If not I'll check it tonight.
Thanks
Wayne
 

TheOldHokie

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L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
96
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Myersville, MD
Before you connect anything you need to determine exactly how the valve on the backhoe operates. If it has a P, PB, and T port you need all three connected to the appropriate points on the tractor's system.

P = pressure IN to the valve
T = tank return to the reservoir
PB = pressure OUT to next valve in the series

Did you get the manual with the backhoe? I think that is required reading before blindly hooking things up.

Dan
OK - found the Rural King manual for your backhoe and it is less than helpful. There are no instructions for connecting the hydraulics just this system schematic. If I am interpreting it correctly the valve is a vanilla open center valve with no power beyond functionality. It is basically designed to operate off a dedicated pump and reservoir, and has two connections:

P - high pressure IN from pump
T - low pressure OUT to tank

There is no power beyond circuit in the valve. To connect it to tractor hydraulics you need a constant flow OUT from the tractor's system and a direct tank return as in a remote hydraulic outlet held in the open position. I have a 4 way 3 position remote valve with detent on my L3901 for just such an application - in my case a log splitter. Now we can debate using the T port on the backhoe as a power beyond port if you wish but that tends to get people excited.

Dan
RKBH.jpg
 

kubotafreak

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Equipment
GRAND l6060, L3560, B6100, gr2100, tg 1860, g1800, g1900, g2160
Sep 20, 2018
401
93
28
Arkansas, US
Thanks Kubotafreak,
I like this approach. Seems straight forward. Is there any need to connect the loop if I don't have the BH on the tractor or an issue of dead heading the system? This looks like the way my rear remote is configured on my other tractor but feeds a remote self centering control valve designed to operate the hyd center link.
Wayne
You will have to keep it looped when not using backhoe.

From what I can tell your l30 tractor has a different manifold, where if I am not mistaken the three point is fed first from a hard line from the pump. If you have a loader, they manifold off of this feed source, and feed the aluminum manifold for the front loader giving it priority. You can either take power beyond from the loader valve or this aluminum manifold. (manifold would be easier) Let me check this evening on the plug size. I believe it is 1/2 jic 90 to #10 orb.
 

MDCobraMan

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Equipment
Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
25
12
3
21102
OK - found the Rural King manual for your backhoe and it is less than helpful. There are no instructions for connecting the hydraulics just this system schematic. If I am interpreting it correctly the valve is a vanilla open center valve with no power beyond functionality. It is basically designed to operate off a dedicated pump and reservoir, and has two connections:

P - high pressure IN from pump
T - low pressure OUT to tank

There is no power beyond circuit in the valve. To connect it to tractor hydraulics you need a constant flow OUT from the tractor's system and a direct tank return as in a remote hydraulic outlet held in the open position. I have a 4 way 3 position remote valve with detent on my L3901 for just such an application - in my case a log splitter. Now we can debate using the T port on the backhoe as a power beyond port if you wish but that tends to get people excited.

Dan View attachment 61245
I was going to install a pump off the 3 PT but the area around where the PTO shaft protrudes is rather small for the pumps I found and adding the extension is not a great approach.
 

MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
25
12
3
21102
You will have to keep it looped when not using backhoe.

From what I can tell your l30 tractor has a different manifold, where if I am not mistaken the three point is fed first from a hard line from the pump. If you have a loader, they manifold off of this feed source, and feed the aluminum manifold for the front loader giving it priority. You can either take power beyond from the loader valve or this aluminum manifold. (manifold would be easier) Let me check this evening on the plug size. I believe it is 1/2 jic 90 to #10 orb.
I may add a high pressure valve between the QD's so I could rotate the valve to loop the system or close the loop for hoe operation. I'll have to look at the aluminum valve under the foot board and see how it's configured.
Wayne
 

TheOldHokie

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L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
96
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Myersville, MD
I was going to install a pump off the 3 PT but the area around where the PTO shaft protrudes is rather small for the pumps I found and adding the extension is not a great approach.
I know - I was considering the same thing for my 3pt log splitter and may yet do that. Six GPM is better than the 4 GPM the old B7200 was pumping but still puny for a splitter. But for the near term I will be adding two DA remote valves with float along with one DA remote valve with 3 position detent as a quick and dirty way to get constant flow and a direct tank return for the splitter. When the splitter is not connected that valve will work fine for cylinders albeit no spring return to center.

Dan
 

TheOldHokie

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L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
96
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Myersville, MD
I may add a high pressure valve between the QD's so I could rotate the valve to loop the system or close the loop for hoe operation. I'll have to look at the aluminum valve under the foot board and see how it's configured.
Wayne
A simple manual diverter valve will do what you want. Valve is less than $100 and hoses and fittings maybe another $200. Not general purpose though and a single spool DA control valve is no more expensive and you get "real" full time remotes with no need for looping anything back when the hoe is dismounted.
 
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MDCobraMan

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Kubota L3430 Grand Open ROPS, L3430 Grand Cab, F2400
Jun 8, 2021
25
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21102

TheOldHokie

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L3901/LA520, B7200DT/LA1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
96
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18
Myersville, MD
Yes but I am cheap and would not spend that much money for that valve. Here is a solenoid switched valve for half that price - you would also need a $2 toggle switch and some wire:

HSV6 Diverter

Still very special purpose and I would go this more general route:

Summit P40

Order it with the 2 position detent option and a power beyond sleeve and two quick couplers for the ports. Plumb it into the tractor hydraulics by daisy chaining off the loader valve as discussed earlier. That gives you a place to hook up your backhoe - just plug the hoe in to the work ports on the remote and shift the spool to supply oil to the hoe from one work port and the return work port going straight to the tank. It also gives you DA remotes for a cylinder when the hoe is not mounted.

And there is no need to stop at one spool - the incremental cost for two or three spools is quite small...., :rolleyes:

Dan