Third function dirverter valve vers True 3rd function valve

[powerscol]

OK folks - been doing some reading and I am finding two different terms being used. One is a diverter valve to create a 3rd function and the other is a true 3rd function valve. In looking at pictures some have one solenoid and other have 2 - usually in a grapple set up. I am just doing research trying to understand function and placement. I have a hay grapple running off of rear remotes, It takes an A_B circuit, In other words push lever one way to hook and pull back to unhook. Im planning on getting a rear blade that can take up to 3 remote sets to operate (swing, tilt and offset) I would also like to keep my hydraulic top link, so I know out back I need at least 4 sets. It would be possible I need 5 if I use the blade as ballast while moving hay.


So in looking at various pictures here I think I would need a twin solenoid set up like several sell here. There should be 2 input ports and 4 output ports, one set goes to the original function and the other two controlled by the solenoids to act like a A-B pair using 2 buttons mounted somewhere on the joy stick, or a replacement head with the buttons built in. Now I have no clue what a single solenoid would be used fore up front but found pictures on the net.

Question 1 - what is the difference between a diverter set up and a true 3rd function set up?

Question 2 - In what circuit is the set up normally placed. Loader lift function, or curl function?

If I understand the operation I might use the curl to set the grapple over the bales, then to hook up the Bales press the button while moving the joy stick to lower the loader to operate if the 3rd function was installed in the loader up/down circuit. Am I understanding this correctly? To unhook would I be pressing a button while pulling back on the loader control, or would it still be forward - or does it matter which way the flow is coming?

Thanks for any help or links that might explain this better.

BTW this is a great place to spend time reading and learning when you can't do anything else I had a rotater cuff and bicep repaired, so not much I can do. I tore it loosing the world arm wrestling championship :confused3::laughing: So far so good - PT is a real H*$$ as they work to get full motion back. I love the stim treatment (electric shock pads) and ice pack though after everything is over.

 

[Sysop]

Question 1:
Basically, a true third function has two switches; one to extend a cylinder, the other to retract it. When you press one of the two buttons, one of the two solenoids opens a valve to actuate the cylinder.

A diverter is going to have one button. When you press it, it switches the flow path from the "diverted" function to the 3rd function ports. You then move the existing lever one way or the other to activate flow at the 3rd function ports.

The main differences are:
-With a diverter, you are disabling one of the functions when the button is pressed, but you can feather the lever to adjust the flow and pressure. A skilled operator could use a grapple to take hold of someone's hand without crushing it easily. (hush up safety police)
-With a true 3rd function, as long as you are feathering the controls enough to still have flow at the power beyond, you can operate all three functions at once. You have no control over the speed or pressure it operates. There is a high probability even a skilled operator would crush a persons hand if they tried to take hold of it with a grapple. (again, hush up safety police)

For some people, diverters work best, for others, 3rd function. I think the most popular opinion is that a skilled operator can be slowed down with a diverter and there is little downside to a 3rd function. But if you occasionally want to clamp down on pallets or pipes or other things that could be damaged, a diverter is the way to go.

Question 2:
3rd function goes on the power beyond port of the loader valve.

Diverter can go on either curl or lift, whatever will work best for your uses. If I were going diverter, it would likely go on my lift circuit so I can curl/roll a grapple while gently pinching down on something precisely.

 

[RNeumann]

The true third function comes off the power beyond from the loader valve or rear remotes (depending on how it's plumbed) and allows you to lift, curl and 3rd function at once. This setup has 4 ports- power beyond in and out and 2 flow ports.
The diverter valve goes between the loader control valve and (typically) the curl cylinders. When you activate the diverter you lose curl and those same loader controls now control the third function. This isn't true third function since it doesn't allow curl at the same time. This setup has 6 ports. 2 in, 2 to curl cylinders and 2 to third function.

The true third function valve is closed until you press the button. One button sends fluid in one direction (say open a cylinder) and the other button sends the fluid in the opposite direction (say close a cylinder).

One of your rear remotes can be used as a "third function" by running the hoses from the back to the front. With this setup you would have one hand on the loader joystick and then use your other hand to control the third function. Personally this would drive me nuts! But several on here not only do this, but like it.

If you want a nice valve for the third function check out the Hyvair DO3 or DO5 depending on flow requirements. This style valve (all brands) can run warm so over sizing isn't a bad thing if you have the room.

Good luck.

Edit- looks like Sysop and I were typing at the same time.....

 

[powerscol]

Excellent information - Thanks. This old guy thinks he understands now, This really helps in my quest, RNeumann - I currently have lines to the front from the rear remotes, so your suggestions makes sense, I don't believe my Bobcat CT 235 has a power beyond port, so Ill keep looking into the diverters - especially as I have the lines to the front already. When I add my additional remotes to the back I might set out up a dedicated one to the hay grapple on a rocker switch. Another cup of coffee and Ill do a bit more thinking, Supposed to rain today, so not much else to do but taxes.

 

[RNeumann]

The lines to the back must go into a valve. That valve should have Power Beyond (PB). So you should be able to come out of the rear valves and into the front control.
Based on what you are describing google "stackable hydraulic valves" You can add a bunch of valves together at meet all your needs. Some can be electric over hydraulic (what you are describing for the third function) while other can have control levers right on the valve.
Bucher and Prince seem to be the common brands.

 

[AKfish]

Excellent information - Thanks. This old guy thinks he understands now, This really helps in my quest, RNeumann - I currently have lines to the front from the rear remotes, so your suggestions makes sense, I don't believe my Bobcat CT 235 has a power beyond port, so Ill keep looking into the diverters - especially as I have the lines to the front already. When I add my additional remotes to the back I might set out up a dedicated one to the hay grapple on a rocker switch. Another cup of coffee and Ill do a bit more thinking, Supposed to rain today, so not much else to do but taxes.

There's another approach that you might consider in lieu of the electric diverter and selenoid configuration i.e. (Fasse valve). Utilize a power beyond (PB) circuit and several open-center block (spool) valves that are plumbed into the PB circuit.

Your FEL is configured with 2-open center spool valves for boom and curl function. They are mechanically operated via the cables from the joystick. Hydraulic fluid flows continuously from the pump through the valve and back to the sump. When you move the joystick the fluid is directed to a port in the valve by a machined spool to move either the boom or curl cylinder.

A "real" dedicated SCV works this way in an open-center hydraulic system. The rear mounted SCV is an open-center spool valve that has a mechanical control linkage similar to your FEL system.

I installed a rear fender mounted block valve with a single-lever control routed thru the PB circuit to control a hydraulic top link on the 3pt.

I have also seen folk's here on TBN use this configuration for multiple, single lever controls. Of course, the complicating factor with this approach is the necessity of routing additional hyd hoses for every cylinder you want to use.

A major advantage is you won't be "switching" your existing hyd functions on and off; on and off. And forgetting which function is on and which is off and fumbling with switches and rocker switches and looking for a light that indicates what hyd functions are on... In the heat of working and if you have a mini or a major catastrophe - the last thing you want is fumbling for a switch and switching the wrong d@mn one!

(I have 2 tractors with multiple hyd functions controlled via electric diverter.). If I could convert those diverted hyd functions to direct controlled spool valves... I would - in a heartbeat!

 

[N2DFire]

Excellent information - Thanks. This old guy thinks he understands now, This really helps in my quest, RNeumann - I currently have lines to the front from the rear remotes, so your suggestions makes sense, I don't believe my Bobcat CT 235 has a power beyond port, so Ill keep looking into the diverters - especially as I have the lines to the front already. When I add my additional remotes to the back I might set out up a dedicated one to the hay grapple on a rocker switch. Another cup of coffee and Ill do a bit more thinking, Supposed to rain today, so not much else to do but taxes.

Hey man - sucks to hear about the rotator cuff - hope your rehab goes well & you heal up fast. Your CT235 is (from what I understand) pretty much a Kioti CK35 painted white. Just so happens I have enough knowledge about one of those to be dangerous.

The lines to the back must go into a valve. That valve should have Power Beyond (PB). So you should be able to come out of the rear valves and into the front control.
Based on what you are describing google "stackable hydraulic valves" You can add a bunch of valves together at meet all your needs. Some can be electric over hydraulic (what you are describing for the third function) while other can have control levers right on the valve.
Bucher and Prince seem to be the common brands.

Rneumann is right on track. The Power Beyond port on the loader valve has a Hard Line w/ banjo fittings that runs from the valve body to the rear of the tractor. This line provides the fluid flow for the 3pt lift (and in your case) the 2 factory rear remotes.

As Sysop been stated before you can install a diverter on the curl/dump function of your loader circuit or for a true 3rd function - this hard line is what you would split.

There are a few diverter kits & 3rd function kits on the market that are pretty much bolt-n-go. There were little things about each I didn't like so I ended up designing & building my own. I created a write-up here. Be sure to read thru the whole thread as this was a learning experience (and design on the fly) thing for me so I have some updates and "would have done different" scattered among the comments.

http://www.tractorbynet.com/forums/customization/358086-kioti-ck-35-3rd-function.html

As to your need for 4 rear remotes, I am still in the process of trying to get myself to buy the 2 remote factory kit (for a top-n-tilt set-up) and have been thinking about what I would do if I needed more remotes. I think a dual diverter setup could be done fairly easily and that would get you 4 functions; but I honestly have no idea what the factory rear valves, plumbing, and mounting look like first hand so it may be a huge pain too.

Best of luck in your research & project.

 

[LD1]

In regards to question 2, about using curl or lift for a diverter....

On my machine I had no choice. I HAD to use the lift circuit. My loader valve in "dump" mode is regen only. Meaning it puts pressure out BOTH ports. This causes the curlcylinders to extend due to the difference in piston area, however at a much less force. No problem on a loader dumping as you have gravity helping. But a grapple that needs the force, it dont work well. And a pair of single acting cylinders like angle on a snow plow, it just wont work at all.

Some loaders have a detent in the curl where you have both normal and regen as options when dumping. IF regen happens to be the first detent and you have to push further to get to normal mode, I dont think I would like that on a diverter either. It limits the feathering ability. And for grapple work anyway, I like it on the lift/lower. For the snowplow, I would prefer it on the curl so the left-right movement of the joystick would correspond with with movement of the plow, but it is what it is.

 

[ovrszd]

I'll add a bit of clarity that applies to 90% of tractors. If someone has a different scenario, clarify it for knowledge sharing.

Tractor hydraulic pump output goes to FEL valves, if no demand it then PB's to rear remotes, if no demand it then PB's to 3pt.

If you add diverter for 3rd function it simply switches the path of that circuit between lift/curl of the FEL to 3rd function. All other subsequent paths I mentioned above stay the same.

If you add "true 3rd function" it is added just after the FEL valves PB. So now your path is pump to FEL, PB to 3rd function, PB to rear remotes, PB to 3pt.

If your tractor has adequate flow it can perform FEL lift, FEL curl and 3rd function. Any pressure applied beyond that will be minimal at best. So in the case of my M9540 with true 3rd function I can lift, curl, grab and still get slight action out of one rear remote. Other two rear remotes and 3pt won't move at all until actions start ceasing in the beginning of the "chain". As each of those actions cease power is increased to the next action in line.

From what I've read here on TBN smaller tractors struggle to truly use 3rd function. They just don't have enough flow to do that. Those tractors might be better served using a diverter?

 

[ericm979]

That's a really good point.

I have some hydraulic novice questions:

Is there a way to calculate "reserve capacity" when operating the FEL to see if the tractor has enough GPM to operate the loader and 3rd function simultaneously? Like by taking the cycle time of the loader cylinders and their volume to calculate how much fluid they use per second?

Is the chain a strict priority? I.e. cylinders on the first valve get all the flow they can use and only the remainder goes to the next in line? Or are the connections from one valve in the chain to the next more like a tee, so cylinders on the first and second valves share flow equally? Or some combination of the two depending on flow restrictions in the system? Maybe it does not matter.

 

[LD1]

That's a really good point.

I have some hydraulic novice questions:

Is there a way to calculate "reserve capacity" when operating the FEL to see if the tractor has enough GPM to operate the loader and 3rd function simultaneously? Like by taking the cycle time of the loader cylinders and their volume to calculate how much fluid they use per second?

Is the chain a strict priority? I.e. cylinders on the first valve get all the flow they can use and only the remainder goes to the next in line? Or are the connections from one valve in the chain to the next more like a tee, so cylinders on the first and second valves share flow equally? Or some combination of the two depending on flow restrictions in the system? Maybe it does not matter.

Its not a simple calculation based on GPM.

Hydraulic oil, if you are trying to command it to do multiple functions, is gonna take the path of least resistance.

Raising a loader that is empty, takes about 500-600psi on most machines. Dumping the loader or opening the grapple takes far less. Even closing the grapple takes far less until it actually starts to clamp down. So if you try all three of those at the same time, odds are the loader lift is gonna be pretty sluggish, at least until the grapple closes or you stop dumping.

Same way with power beyond. With the loader being the first in line, and your 3PH usually at the end of the line. Whatever reserve is left goes to the 3PH last. IF you try raising your loader and 3PH at the same time the front end loader is certainly gonna lift because it is first in line. Whatever is left will go to the 3PH. But remember, it only takes500-600psi to raise that loader. Normally that will also be sufficient to raise the 3PH as well, so both will normally move but the 3PH will be at a slower speed.

Now if you have something heavy on the back of the 3PH that "may" require 1500PSI to lift under normal conditions, odds are it isnt gonna lift until you let off the FEL. Because the oil is taking the path of least resistance. And in this case, thats the 600psi required to raise the loader.

Try it sometime. With nothing on the 3PH both the loader and 3PH should lift normally. Now put your heaviest attachment out back and try again.

 

[ovrszd]

What he said.

 

[powerscol]

Hey man - sucks to hear about the rotator cuff - hope your rehab goes well & you heal up fast. Your CT235 is (from what I understand) pretty much a Kioti CK35 painted white. Just so happens I have enough knowledge about one of those to be dangerous.



Rneumann is right on track. The Power Beyond port on the loader valve has a Hard Line w/ banjo fittings that runs from the valve body to the rear of the tractor. This line provides the fluid flow for the 3pt lift (and in your case) the 2 factory rear remotes.

As Sysop been stated before you can install a diverter on the curl/dump function of your loader circuit or for a true 3rd function - this hard line is what you would split.

There are a few diverter kits & 3rd function kits on the market that are pretty much bolt-n-go. There were little things about each I didn't like so I ended up designing & building my own. I created a write-up here. Be sure to read thru the whole thread as this was a learning experience (and design on the fly) thing for me so I have some updates and "would have done different" scattered among the comments.

http://www.tractorbynet.com/forums/customization/358086-kioti-ck-35-3rd-function.html

As to your need for 4 rear remotes, I am still in the process of trying to get myself to buy the 2 remote factory kit (for a top-n-tilt set-up) and have been thinking about what I would do if I needed more remotes. I think a dual diverter setup could be done fairly easily and that would get you 4 functions; but I honestly have no idea what the factory rear valves, plumbing, and mounting look like first hand so it may be a huge pain too.

Best of luck in your research & project.

ND2Fire - The Kioti rear remotes are easy to install. The most time spent was removing the seat. You do not need to remove the tire as the instructions say. remove 2 bolts, install the valve bodies against the trans block, renstall the block cover and tighten up. The run the hard lines to the rear. They fit well so no routing issues. Took my dealer less than an hour as I am not the best with tools, I actually have the Kioti 2nd remote on my bobcat as it has a float feature. I plan to use this circut for my additional divertors, I plan to do a simular set up as Brian did on his tractor. I think I have found a mounting place, just need to cut up some foam (build a mock-up) to see if it will fit,

Thanks everyone - I am still learning a lot
Keith

 

[tractorshopper]

My small BX-2370 has the diverter valve configuration. I don't want this to sound as bad as it will sound, but I'm pretty coordinated and do get limited in my operations sometimes by how it slows down when I'm trying to lift, curl, and finish closing (tightening) all at the same time. I do wish it would keep doing all 3 at the same rate, but one of curl or lift will kind of stop or get jerky for a second like it's trying to figure out priority. This also happens a little when I'm trying to back up from a pile while lifting, opening, and curling.

That said, I just have to stop for a second to finish one or the other, but if all 3 had same priority and speed, I could actually wheel right into/out of piles a smidge quicker. It's not enough to drive me insane and doesn't happen that I could gain from it all the time, but literally just takes another second here or there while in constant work conditions. I just deal with it by taking my foot off the treadle until whichever operation is done.

Knowing how awesome it is to have a grapple and the amount of work it can do keeps me happy regardless if I could have saved a second here and there.

 

[ericm979]

Its not a simple calculation based on GPM.

Hydraulic oil, if you are trying to command it to do multiple functions, is gonna take the path of least resistance.

Raising a loader that is empty, takes about 500-600psi on most machines. Dumping the loader or opening the grapple takes far less. Even closing the grapple takes far less until it actually starts to clamp down. So if you try all three of those at the same time, odds are the loader lift is gonna be pretty sluggish, at least until the grapple closes or you stop dumping.

OK, got it. All the cylinders attached to open valves get pressure but it's the cylinders with the least resistance that will move first. Makes sense, thanks.

 

[RNeumann]

I understand the concern about running out of GPM if you were to lift, curl and 3rd function at once. Most of the time this is done it's only for a second or two- say you have a grapple- you would open the grapple, roll the curl down and lower the FEL onto a pile of "stuff" The next move would be to close/squeeze and curl to maximize the amount you could pick up. If for some reason the grapple tine hit something you may lift slightly. This would be a case of lift, squeeze/close and curl at once. But mostly it's just one at a time or curl and close/squeeze at the same time.

 

[LD1]

All the cylinders attached to open valves get pressure but it's the cylinders with the least resistance that will move first.

Not exactly.

The first valve I. The series will get priority and move no matter what.

The rest of the valves downstream will ONLY move if the pressure requires to move that cylinder is LESS than the first valve in the series. (And you still have flow) IE: the 3ph will lift while the loader is also lifting IF the load is less than the loader load.

As mentioned, most tractors go FEL→3rd function(if equipped)→remotes (if equipped)→3ph.

A diverter is part of the FEL valve So if trying to use grapple and another loader function at the same time, the one with the least resistance moves first and fastest.

It is never an exact science. It all comes down to flow and pressure and how much you have. But in general, things follow In the order that it's plumbed. But simply changing rpms (changing flow) can change how the whole system operated.

Don't get hung up on it too much. If you think you will want to lift, curl, and close grapple ALL at the exact same time, then get a true 3rd. I consider myself fairly skilled. Been running g equipment all my life. And 4-stick backhoes for years. I have never felt limited with a diverter. And like the precise control (speed and force) that I get with the diverter

 

[ovrszd]

I understand the concern about running out of GPM if you were to lift, curl and 3rd function at once. Most of the time this is done it's only for a second or two- say you have a grapple- you would open the grapple, roll the curl down and lower the FEL onto a pile of "stuff" The next move would be to close/squeeze and curl to maximize the amount you could pick up. If for some reason the grapple tine hit something you may lift slightly. This would be a case of lift, squeeze/close and curl at once. But mostly it's just one at a time or curl and close/squeeze at the same time.

I just spent the day in the timber using my Grapple to clear and transport small brush. I used all three functions every time I was trying to pick up something.

I think there is different levels of Grapple use. If I used my Grapple as you describe, I could get along fine with a Diverter valve. I think your tractor would probably benefit from a Diverter due to limited hydraulic flow. Even if you had 3rd function, I'm not sure your tractor could support it.

This is why I mentioned it earlier. Gotta keep in mind there are a wide range of tractors in this discussion.

 

[ovrszd]

Not exactly.

The first valve I. The series will get priority and move no matter what.

The rest of the valves downstream will ONLY move if the pressure requires to move that cylinder is LESS than the first valve in the series. (And you still have flow) IE: the 3ph will lift while the loader is also lifting IF the load is less than the loader load.

As mentioned, most tractors go FEL→3rd function(if equipped)→remotes (if equipped)→3ph.

A diverter is part of the FEL valve So if trying to use grapple and another loader function at the same time, the one with the least resistance moves first and fastest.

This is the part most readers struggle to understand.\

My FEL valves retain all of the hydraulic pump's pressure and flow first. If they don't need it they pass it on thru the PB, similar in function to pressure relief to my 3rd function.

My 3rd function valves, second in line, only get power if the FEL lift/curl doesn't use all of the pump's capacity to complete whatever action they are doing.

My rear remotes, third in line, only get power if the FEL lift/curl and 3rd function don't use all of the pump's capacity to complete whatever action they are doing.

My 3pt, fourth in line, only gets power if the FEL lift/curl, 3rd function and rear remotes don't use all of the pump's capacity to complete whatever action they are doing.

See how the "odds" of any useable "force" diminishes as you go down that line?? So a tractor with minimal hydraulic gpm flow is going to fail to compete an action earlier in the "chain" than a tractor with greater hydraulic gpm flow.

 

[powerscol]

ovrszd
Thanks for the information. My Bobcat is as you describe, FEL-rear remotes-3pt. As is I can only lift/drop and curl partially (is not uniform in motion) I also know my 3pt is last as when I have my remotes in float the 3pt will not work. In going over my system I do not see a power beyond as that port is covered by the rear remote valves. There does not appear to be a port at the loader control valve either. Perhaps I am not looking correctly. Ill call Bobcat tomorrow and check. I dont see any exposed tubing as everything appears to be bolted directly to the trans housing

My grapple operation is as follows. Operate the loader controls to place the hay grapple over the bale and engage the hooks. Right now I stop and grab a rear remote lever to engage the hooks, so there is a gap between loader and and grapple. It appear I need a true 3rd function to be able to operate the hooks from a switch on the loader joy stick, otherwise I would still need to stop and move a rear remote lever. With a diverter I would momentarily loose a loader function when engaging the hooks.
Question - will the loader arms and curl still hold when the diverter is operated? Example loader at full height and grapple set to place bails on hay stack. If the diverter is on the lift circuit, will the loader arms drop when flow is diverted to release the hooks?