3rd function valve

[MtnViewRanch]

All that link tells me is that there is a 3rd function kit available. It is listed as a loader option. Do you think it might/could be used for something else.

If the solenoid and subplate kit is not used for the loader, do you still call it a true 3rd function.

I use the 3rd function term just to indicate there is a solenoid valve on a sub plate perhaps making it a true 3rd function kit.

There must be a problem with the terminology if one has to describe a valve as a true 3rd valve. What is an untrue 3rd valve.

This does not have to go further unless you all want to.

Perhaps someone will find the true definition of 3rd function.

I thought all my facts were fairly accurate. I know if they are not, you guys will surely set me straight. Don't beat me up to much.

From what I have seen, these kits are listed as loader options. Can they be used for something else, you bet. But when they are used for use on-with a loader, that is when they become a 3rd function valve-kit, in my mind anyway.

 

[the old grind]

Thanks, J_J! Whatever I do have on the loader is convenient for all my work as is. I've been picturing including a 6-port diverter, but IIRC the one Tony showed me was 4(?)-port and to me this will work if all return oil is routed ok ('optioned'?) to sump with my setup. (I guess this valve is what's used on MIE's Kioti 'drop fit' kits with some hard line) and might obviate some of the extra hoses (2?) I'm imagining .. ?

btw: curl spool has regen on dump. Can that mean I might feather a grapple lid ... if it's in any way like having float on the curl spool when activated? (not sure I'd want to ..)

I appreciate the help, and hope what I'm throwing out may bring forth some pics or something that uh .. haven't appeared in recent similar discussions. I wish I was that much closer to getting my NH to MIE's shop. :hissyfit: (matter of days, now ...)

 

[J_J]

Some loader valves have regen in the first part of lever travel, and others at the far right.

Kubota seems to have the odd valve with the regen in the first part of lever travel.

A four port subplate will route the pump flow from the T port downstream.

If you have the four port valve for your grapple, you will not have any feather. It will be full flow..

 

[Tractor Seabee]

I believe that someone coined that term when they wanted to add a third valve, not spool. However I don't know for sure.

The first valve on just about any tractor is the 3pt valve. Loaders are an add on with one valve and two spools.

On the Kubota BXs that come standard with a backhoe the BH is first, the FEL is second, and the 3PT is the last in the PB circuit. PS is a separate flow pattern from a priority valve.

So I guess not all tractors are equal.

Interesting conversation anyway JJ, glad you thought it up. Maybe we all will learn something or remain confused by all this terminology. Seems like I have always seen 3rd function applied to the FEL ands not other attachments.

Ron

 

[Leejohn]

I am going to answer my own question, in what I THINK from experience. I believe there is some flow to the PB port even if the loader valve is operated fully open to say raise the lift.. But it will be pretty slow, with the flow rates we see on CUTS. That is what I think.

I would say thats right, if the flow rate match that of the tractor. In and out port are alot larger then the work ports. Now if the flow rate is 8gpm and you put on a 25gpm valve then maybe the loader could use all of the 8gpm. I would say that it would use all of it.

 

[J_J]

On the Kubota BXs that come standard with a backhoe the BH is first, the FEL is second, and the 3PT is the last in the PB circuit. PS is a separate flow pattern from a priority valve.

So I guess not all tractors are equal.

Interesting conversation anyway JJ, glad you thought it up. Maybe we all will learn something or remain confused by all this terminology. Seems like I have always seen 3rd function applied to the FEL ands not other attachments.

Ron

Let me answer your statement this way.

I believe the tractor rolls off the line with one valve, the 3pt valve,making it the one and only valve, and them the BH is added later, probably at the dealer and then the hyd flow is redistributed, and then later, maybe a loader is added, making it the first valve in the hyd system.

Do you know for sure that the pump flow go to the BH first?

It would if there was no loader.

Just my thoughts.

 

[sparc]

Wouldn't these terms have originated with the first tractors to offer hydraulics other than the 3pt lift?

It was not the first most likely, but didn't old Fords have a valve plate that was added to provide a 2nd function, and then another valve plate could be stacked on top of this to add a 3rd function?

There were attachments then loaders which were used way back, I don't see why/how the label of 2nd or 3rd function would be tied to a loader only and then mis-used, as some have eluded to here, for other attachments. I think they had generic names because they could be used with so many different attachments.

Some examples of the add-on valves plates I'm referring to.

 

[Tractor Seabee]

Let me answer your statement this way.

I believe the tractor rolls off the line with one valve, the 3pt valve,making it the one and only valve, and them the BH is added later, probably at the dealer and then the hyd flow is redistributed, and then later, maybe a loader is added, making it the first valve in the hyd system.

Do you know for sure that the pump flow go to the BH first?

It would if there was no loader.

Just my thoughts.

JJ,

The flow pattern is very clear in the WSM for the BX25. Also you can only buy the BX25 w/FEL and BH. The same basic tractor is offered under different Model #s. You cannot install the BH on those models. I have no idea on them but the FEL is optional as well as the front HYD joy stick for other front attachments. I would assume the FEL then is first but ???

Ron

 

[J_J]

Looking at the BX25 pump circuit from Messnicks, it looks like there is a a cover plate which they remove and install a thread cover plate with two ports which feed the BH.

You guys should have the manual, but I will bet that when they install a loader, the PB port from that adapter plate goes to the loader and the PB from the loader comes back to feed the BH, and the BH return fluid comes back to the adapter plate and then feeds the 3pt.

{ Well, I lost that bet. } see post 51

Do you have the hook up for the loader or is it a dealer function?

If all that is true, then the loader relief is the master relief for the hyd system.

 

[Tractor Seabee]

JJ and all,

Attached is a copy of the HYD diagram from the WSM. I have drawn flow arrows on it for clarification. Note item 11 the relief valve, it establishes the pressure right at the pump, it is part of HST housing casting. Items 4 and 3 are the control valve and cylinders for the 3PT. When the BH is off the P hose plugs into the PB circuit going to the FEL as the P input. The BH valve block is a PB and there are three hoses to/from it.


Ron

 

[J_J]

Yep, I do see now, and the flow does go to the BH first,and then to the loader. . So the BH will have priority over anything else.

There must be a relief valve on the hyd block, as it is before the BH.

I don't see a relief valve on the loader valve, but I do see three relief valves on the BH valve.

The loader also feeds the 3pt valve.

 

[Rustyiron]

Talk about misuse of a term, look what they call a Marriage these days!:laughing::laughing:

 

[Tractor Seabee]

Yep, I do see now, and the flow does go to the BH first,and then to the loader. . So the BH will have priority over anything else.

There must be a relief valve on the hyd block, as it is before the BH.

I don't see a relief valve on the loader valve, but I do see three relief valves on the BH valve.

The loader also feeds the 3pt valve.

JJ, The main circuit relief is an attachment to the HST housing and it is the main relief for the attachment and 3PT circuit. What you may see as a relief valve at the BH valves is what they call a Load Check Valve in one place and an overload relief valve in another (appears to be one assembly performing both functions). There is one in the bucket valve and 2 in the swing valve. They are spring loaded but not field adjustable. The FEL has no relief valve. Attached are some more drawings. Reading the WSM manual it comes clear to me as it seems well worded and complete; I think.



We've gotten off the track on the OP but now that we started this might as well enlighten a few of our TBNers that eat this stuff up.



Ron

 

[jeepguy]

First reply for me, but a long long time reader on TBN. I bought a Kubota B26 TLB and want to run a hydraulic chainsaw on the end of the backhoe stick using the backhoe bucket curl circuit. I want to put a T and quick connect on the two hoses running to the backhoe bucket curl cylinder. The bucket will be removed and the chainsaw placed on the end of the stick and plumbed into the quick connect Ts. Using the curl on the joystick to forward and reverse the chainsaw. How far off am I in my thinking that this would be an alternative to third function or diverter setups? Thank you.

 

[J_J]

That will work just fine, but you will need to add a relief valve to lower the pressure to the hyd chain saw as I believe they run around 1500 psi.

I may be wrong, but the label on my hyd chainsaw says 1500 psi.

You might have regen on your valve which may give some problems. Of course, you would only want to run the chainsaw in the fwd direction. So use the non regen work port that will do that.

Also check to see if the saw is open or closed center.

 

[jeepguy]

Thanks J.J.

 

[k0ua]

Alrighty then. One experiment is worth a 1000 words.

As for oil flow from the Power Beyond when the loader lift valve is fully operated, or the Dump/Curl circuit is fully operated, NOT one single drop of oil goes to the PB circuit to run the SCV or the 3PT hitch cylinder.. None, and never will until you let go of the loader joystick.

The fluid flow just runs over the PRV (Pressure Relief Valve) which is before the PB circuit. Now if you feather the loader control to have the lift rising either slowly or even moderately fast, the PB circuit receives flow, and the 3PT will raise approximately normal speed (hard to tell without a stopwatch.) In fact it will be fully raised before the lift will be fully raised. I tried this at idle and full throttle, and got the same results. It is not a matter of not enough fluid flow to raise both at the same time, because there is if you don't try to raise the lift or curl fully.

The loader valve just closes off the PB circuit fully when you operate the joystick fully. So that was my big experiment, and that is at least how a Kioti DK35se loader valve and PB circuit works.

 

[J_J]

I have said all that more than once. Some people are very doubtful.

 

[k0ua]

I have said all that more than once. Some people are very doubtful.

Well we won't be doubting you any more!:thumbsup:

 

[J_J]

Yep, I do see now, and the flow does go to the BH first,and then to the loader. . So the BH will have priority over anything else.

There must be a relief valve on the hyd block, as it is before the BH.

I don't see a relief valve on the loader valve, but I do see three relief valves on the BH valve.

The loader also feeds the 3pt valve.

For those that think the loader is the first and second spool in the FUNCTION list, Looking at the BX25 brings up a new situation, as the hyd flow goes to the BH valve first. First six function is the BH valve with 6 functions.

Now, does that make the BX loader, the seventh and eighth function after the BH?

Unless someone can prove that the loader is the first and second function, I just don't buy it.

But again. Call it what you want.

Da**, I just realized I've got a TRUE 3rd function valve with relief for the rear of the tractor, but with no loader how is that possible? It must be a TRUE first function.

What happened to my first and second function.