Backhoe Thumb Hydraulic Options

[avc8130]

Do you need the complete valve, or a couple of spools to add to the current valve?

I'm not sure on the terminology. Kubot uses a stack of valves to control the backhoe. For the factory thumb option, they add a valve to the stack. This "addition" is $560 without the hoses, fittings, foot control, etc.



That last piece in the stack before the end cap is the thumb "valve".

ac

 

[J_J]

You should be able to get replacement spools for that stacked valve.

You may not be able to add to the stack assembly and make it fit in the allowed space.

You can add a 3rd function valve to move the thumb, or if the BH valve has PB, just add another foot control valve.


This is some data from a thumb manufacturer.

CautionCautioCautionn

HYDRAULIC PRESSURE ON THUMB CYLINDER SHOULD NOT
EXCEED 2000 PSI. IT IS ESSENTIAL TO PERFORM TESTS TO
ENSURE THAT THE BUCKET AND ATTACHMENTS ALWAYS
OVERPOWER THE THUMB. FAILURE TO DO SO WILL CAUSE
DAMAGE TO THUMB, PINS, CYLINDERS, BRACKETS AND STICK.
Valve

 

[avc8130]

You should be able to get replacement spools for that stacked valve.

You may not be able to add to the stack assembly and make it fit in the allowed space.

You can add a 3rd function valve to move the thumb, or if the BH valve has PB, just add another foot control valve.


This is some data from a thumb manufacturer.

CautionCautioCautionn

HYDRAULIC PRESSURE ON THUMB CYLINDER SHOULD NOT
EXCEED 2000 PSI. IT IS ESSENTIAL TO PERFORM TESTS TO
ENSURE THAT THE BUCKET AND ATTACHMENTS ALWAYS
OVERPOWER THE THUMB. FAILURE TO DO SO WILL CAUSE
DAMAGE TO THUMB, PINS, CYLINDERS, BRACKETS AND STICK.
Valve

There is plenty of space for the thumb addition on the stack. Kubota designs it perfectly, even including the extra threaded mount bosses and everything. That last valve that you can see in the picture that is operated by the foot pedal is NOT currently installed on my machine. That is what I would need to add.

We really need a FAQ in the hydraulic section, at least to establish what all of these terms mean so we can talk with the same vocabulary.

ac

 

[J_J]

Someone has done some of the abbreviations explanations but not all in one spot.

Just what something means.

Sometimes it is just easier to use short titles.

 

[avc8130]

Someone has done some of the abbreviations explanations but not all in one spot.

Just what something means.

Sometimes it is just easier to use short titles.

Right, so if I wanted to add the factory style setup...what do I need?

Here is the parts diagram from Kubota. You can see how they just add a valve/spool (what is the proper term?) to the stack (proper term?).



How can I figure out if there is a commercial way to get that component without paying Kubota's $560?

ac

 

[J_J]

Is there a name or number on the valve anywhere?

Have you checked what one spool would cost, and the longer bolts required?

Did you compare the stacks to Prince or any other manufacturer?

What is included in the $560 price?

You might visit the hyd shop in the dealership and inquire about a used stack.

Sometimes the guys in the back will help more than the service manager.

 

[avc8130]

Is there a name or number on the vale anywhere?

Have you checked what one spool would cost, and the longer bolts required?

Did you compare the stacks to Prince or any other manufacturer?

What is included in the $560 price?

You might visit the hyd shop in the dealership and inquire about a used stack.

Sometimes the guys in the back will help more than the service manager.

I'll have to take a really close look at the stack when I get home.

$564 buys "010" from that picture.

ac

 

[J_J]

That price is tota BS.

Here is a stack valve from this vender and each stack is aobut $80

Sectional Control Valves

Here is the stack prices from Surplus for their stacked valve.

Spring center with port relief is only $128.

Surplus Center - 7 SPOOL SV VALVE OPEN CENTER W/POWER BEYOND

If you have to stick with your valve, then I would go 3rd function or diverter valve.

You could even install a log slitter valve on the thumb and have it retract to rest automatically using detent.

There are many ways to do this.

Some people want to play with the thumb, and others just want to place/set the thumb using a cyl and leave it stationary for the duration of the work.

 

[J_J]

This BH valve with 6 spools cost about $480, and you can add another $80 valve using the PB port.

Directional Control Valves 22 Series | Type 4-way 3 pos. tandem center 6 SPL W/2JOYSTICKS 220-951

 

[avc8130]

That price is tota BS.

If you have to stick with your valve, then I would go 3rd function or diverter valve.

You could even install a log slitter valve on the thumb and have it retract to rest automatically using detent.

There are many ways to do this.

Some people want to play with the thumb, and others just want to place/set the thumb using a cyl and leave it stationary for the duration of the work.

Exactly my point. Kubota's price is insane. That is why I was hoping to find a valve that would be compatible with the stack to add.

I guess it is unknown who makes the valves for Kubota?

As you know, I started this post thinking about a diverter. We have gone in so many circles I'm dizzy now. LOL

ac