Adding 3rd function with bh?

[RickB]

There's no reason that you can't have a 3rd function, backhoe and a hydraulic thumb on the backhoe. And you can have a port to plug the backhoe into if you want too.
It's just a matter of plumbing it all correctly. You can not tee a pressure line.

I agree.

 

[super dave]

Sorry, I wasn稚 very clear (duh on my part). Sink kubota said that using the third function on the power beyond was the way to go. They did my lines also. The third function kit lines were to short. They said that it wasn稚 possible to tee off power beyond for the hydraulic thumb, why I don稚 know or understand. What I am understanding is that bh thumb cylinder has to be able to bleed back so as not damage either bh thumb cylinder or bucket cylinder. I知 not giving up just busy working all the time. I have a big creek to pond project where I will definitely need hydraulic thumb to place rock and grapple as well (next 2 years or so). EA is a great company. I purchased a 55in root grapple that I can稚 praise enough about. I致e moved sheets of steel, crushed empty pallets (by accident). In the fall when use tractor with vac when the leaves are deep and the hoper is full I grab a big pile of leaves with the grapple. Recently I helped my father-in-law drop over 3 yes 3 hundred tall pines and process them. My tractor is only a b3200 but the trees measured between 70 and 80 feet. I could pick the whole tree of the ground about a foot then we used a tap measure then cut and took to the neighbor who has a saw mill. It made great lumber for the new barn. This grapple is awesome. It flex痴 but does not bend like most others,,, well worth the money and very light weight

 

[super dave]

Not sure why my post has weird icons in it???

 

[ericm979]

With open center hydraulics you can't tee off a pressure line. With open center, there is constant flow from the pump. It flows through each valve in turn, then to the 3pt and into the tank. When you operate a valve the flow is diverted, into cylinders or whatever is attached to the valve. It gets a little more complex in that there are two types of valve, one that has just an in and an out in addition to work ports to operate cylinders, and one that has an in, power beyond and tank. Either kind can support other valves after them in the chain (though there are caveats that I'm leaving out to keep it simple). The key thing to remember is that when you operate a valve, it pressurizes the entire chain before it. So they need to be designed for that.

When you put the backhoe on and plug it in, you're just adding it's valve stack to the chain.

You can add a thumb in a few ways. You can put a new valve for it in the stack on the BH. That's the cleanest. You can use a diverter to divert the flow from another BH valve like stabilizer, to the thumb. That can be electric or mechanical. Or you can plumb the thumb in to the tractor. That's when the caveats come in. Many BH valve stacks are not designed to be pressurized by valves farther down in the chain, which is why you're not supposed to operate the 3pt with the BH connected. If you connect the thumb before the BH in the chain, then its valve needs to be able to handle full pressure when the BH is operated. Also, if the thumb is connected before the BH, using it will keep the BH from getting (much) flow, so you won't be able to move the thumb and BH at the same time.

 

[BukitCase]

The link to diagram (Travis) gives an error for me - I looked around long's site and found this

https://docs.wixstatic.com/ugd/701dd3_4fb5a989c44f4e06964d90dea466d811.pdf

HTH... Steve

 

[downsizingnow48]

That is an excellent diagram. To run my hydraulic thumb I inserted another control valve after the 4in1 valve and before the backhoe inlet. Has worked for years flawlessly. I cannot understand why the dealer says it is impossible. Many other TBN folk have done similar.

 

[BukitCase]

"why the dealer says it is impossible" - Pat, it probably IS impossible (for HIM) ...Steve

 

[super dave]

I agree, the dealer wasn稚 happy that I didn稚 purchase 3rd function valve from them and almost turned me away when I asked them to make and install 2 lines. That diagram is what I致e been looking for. This fall I will have my hydraulic thumb

 

[ericm979]

If you search TBN for hydraulic thumb you'll find a bunch of threads describing different ways to plumb it in.