Need Help Connecting Hydraulic lines from BT601 Backhoe to BX2670

[Tractor Todd]

Hello, looking for assistance with connecting hydraulic lines between aBT601 backhoe to Kabota BX2670 tractor.
I have attached pictures, and color coded the lines. Blue, white and yellow come from the backhoe. The yellow is on the left side of the valve body and blue and white on the right side looking forward. The brown hose comes from the tractor. I think I can tee into the pink and green lines.
Any help or schematics and drawings would be greatly appreciated.

 

[Russell King]

You do not want to TEE into any pressure lines!

Go to this website and search for the backhoe model and you can find this diagram that shows how it is connected to the tractor hydraulic connections. That might not help if your tractor has not been set up for a backhoe.

Kubota Tractor Corporation - Illustrated Parts List

- K-PAD - Parts Lists - Illustrated Parts Lists - diagrams

apps.kubotausa.com

 

[North Idaho Wolfman]

Your first problem is you must be working with some chinese knock off tractor and BH as we don't offer help with Kabota tractors, we only do KUBOTA tractors and equipment.

You CAN NOT tee into the hydraulic lines, you need to have a loop.
PB from the loader to the BH and then back to the tractor.
You will need to add a tank line (low pressure return).
You will also need to have a way to connect the loop when the BH is off.

 

[Tractor Todd]

Your first problem is you must be working with some chinese knock off tractor and BH as we don't offer help with Kabota tractors, we only do KUBOTA tractors and equipment.

You CAN NOT tee into the hydraulic lines, you need to have a loop.
PB from the loader to the BH and then back to the tractor.
You will need to add a tank line (low pressure return).
You will also need to have a way to connect the loop when the BH is off.

Thanks for setting me straight on my spelling, it won't happen again. I am new to The Kubota tractors. What does PB stand for? Also is there an easy place to connect the return line. Is the transmission case the tank? I also need help identifing the 3 lines on the back hoe. Thank you in advance.

 

[Tractor Todd]

You do not want to TEE into any pressure lines!

Go to this website and search for the backhoe model and you can find this diagram that shows how it is connected to the tractor hydraulic connections. That might not help if your tractor has not been set up for a backhoe.

Kubota Tractor Corporation - Illustrated Parts List

- K-PAD - Parts Lists - Illustrated Parts Lists - diagrams

apps.kubotausa.com

View attachment 166975

Thank you for the info. I am starting to see what I need to do. My BX2670 was not plumbed for a backhoe.
I see the loop with the 2 lines on the right side. The single line on the left must be the low pressure return.

 

[North Idaho Wolfman]

PB= Power Beyond

So you have three lines Power in (P), Power out (PB), and Tank (return).

Let me dig into the prints and see if I can get you any more info.

 

[Russell King]

@Tractor Todd
Do you have much experience with hydraulics on tractors or is your first venture into them?
I am assuming “little to no knowledge“ so please don’t be insulted if you do have some knowledge.

Kubotas use an open center valve system in their tractors until their larger models. That simply means the hydraulic fluid flows continuously from pump through the valves and back to the tractor sump. It uses the same fluid as the HST transmission and pumps.

The valve will divert the flow to the cylinder and build pressure in one side of the cylinder. Most cylinders are double acting which means they are able to exert force in both directions (can push or pull). As one side is filled with fluid the fluid on the opposite side is pushed back to the sump. That flow is called tank return.

So, in general, the flow to a valve is the Power in and connects to a port on the valve that is labeled P. Then the flow is inside the valve cavity that is the main body and has a few ports that are normally labeled T for tank or N for neutral (as I know it). To get flow (with usable pressure) out of that valve, something has to be installed in the valve to protect it from the dow stream pressure. That is usually called Power Beyond (PB) or High Pressure Carry Over (HPCO). There are sleeves or plugs to be installed in the valve but they must be purchased to match the valve usually purchased at the same time as the valve. Valves will also have two outlet ports to provide flow and pressure to and from the working cylinder.

Some valves do not use a PB connection but use the T port to pass the pressure. Usually a backhoe valve or the third function valves are that type.

So most valves will have a power in hose, a power beyond hose, and a tank return hose. There can be NO TEEs in the power or the power beyond hoses, they must allow flow from tractor to valve to with no diversion. The tank return lines can be TEEd together to return one hose to the tractor.

Most hydraulic problems seem to be from incorrect connections of hoses or incorrectly connected quick disconnects.

(Reference tag for future use)

 

[Russell King]

Your back hoe is using three hoses so the valve has power beyond, power in and tank return hose.

Look on the valve and see if there are any letters cast into the housing. Take pictures if you can and post them if you want.

Your operator manual may have information on how to connect hydraulic accessories (FEL or BH) to the tractor.

 

[North Idaho Wolfman]

It's actually pretty easy to add a BH to that model tractor.
I'm assuming you got all of the subframe to mount it to the tractor.

This is the easy and proper way to tap into the system.

The P line goes to this block.

This is the adapter plate on the side of the tractor.

 

[Tractor Todd]

Thank you for all the information. I now see what needs to be done. I do have one question. I would like to purchase a Kubota original part. It is the PB tube from a BX25 part number 050 so I can connect the loop when the backhoe is off the tractor. Can I order parts online or do I have to go to a dealer?

 

[Tractor Todd]

It's actually pretty easy to add a BH to that model tractor.
I'm assuming you got all of the subframe to mount it to the tractor.

This is the easy and proper way to tap into the system.

View attachment 167011

The P line goes to this block.

This is the adapter plate on the side of the tractor.
View attachment 167009

This is some great information. I can see what I need to do. Thank you.

 

[North Idaho Wolfman]

If you want to do this, you will need a few parts.

 

[Russell King]

This is some great information. I can see what I need to do. Thank you.

Please note that you MAY need to buy the hydraulic block to replace the hydraulic cover. Notice that they are different parts between the upper and lower diagram in post #9.

You need that part if it has not already been installed on your tractor!

 

[North Idaho Wolfman]

Please note that you MAY need to buy the hydraulic block to replace the hydraulic cover. Notice that they are different parts between the upper and lower diagram in post #9.

You need that part if it has not already been installed on your tractor!

No block needed, the bh loop connects before it gets to the block location.
But he should have the block as he has a loader and that's where the loader connects.

 

[Runs With Scissors]

I will just mention that on my 2501 you should not operate/start the tractor without having the pressure line that goes to the BH “plugged back into the tractor"

I think that causes what is called a “dead head” condition and can break things internally.

I think yours is the same………….However, I will be corrected shortly, if I am wrong…………..

 

[Tractor Todd]

I have the backhoe connected and everything works great! I bought and installed part # 140 pump pressure hose and #50 PB tube for a BX25. On the attached pictures I connected the white hose to the P line from pump, Yellow to the PB loop and Blue to Tank return. Thank you to everyone for your input. It really helped a lot. Merry Christmas and happy digging.