Question about Kubota Third Function Valve Operation

[KyleH]

My dealer must have taken them out prior to delivery. :confused3:. Just wanted to make sure I hadn't missed something. Thanks

They were installed on the T fitting where the hoses split to go to both cylinders, they aren't very big, I wasn't too sure if the dealer had removed them until I took the hoses apart from the T fitting to make sure. The instructions don't show them very well. I should be able to make a trip home in a couple weeks, if I do then I'll try to remember to post some pictures of them. It made a noticeable difference in how fast the lid opened and closed making picking up stuff much faster.

 

[Fxfymn]

I hear what everyone is saying and I appreciate the positive vibes, but I really don't think this will work for me. My first thought was to take the 3rd function off, but I'll leave it on to give it a try, but I'm pretty skeptical. I also have a couple of hours in re-routing the hoses and welding up a guard for the hoses coming out of the 3rd function valve box so I kind of hate to give up too early.

I may try the flow restrictor route as I have done this on my splitter's log loader to slow it down so I didn't catapult the logs over the splitter. A washer of the proper diameter that you weld closed and drill out to get the desired flow works well for this. I might get fancy on this one and actually install a valve that I could partially close to get the same effect.

It's partially my fault for not quizzing the salesman a little more when he suggested the 3rd function and some of his for not being clear about how it functions. My thought was it would divert one function of the loader valve which would allow me to use the valve to control the grapple. After reading this I know I could do that, but I really don't want to start tearing into the hydraulics at this point. The rear remotes are a simple solution that are already in place.

I use the loader to load logs into my dump trailer and a big part of that is being able to precisely position the grapple so it will allow the log to slide down the forks until the grapple catches it so I can gently lower it into the bed so as not to beat up the trailer. Between myself and a buddy we routinely carry 15 or more cords of log length wood this way per year and putzing around trying to get the grapple in the right place wouldn't cut it for me.

On the bright side; after a day of cutting and welding I got the snow plow mount in place. I thought it was going to be easy, but the frame of the 4060 is 3/8" wider than the 3410, so I had to cut the mount apart and re-weld it to make it fit. The brush guard on the 4060 is also pretty light compared to the 3430, so I had to add 2x2x1/4 angle to support the plow's lift cylinder. I also had to cut the front plate of the brush guard off and move it back 2 1/2" to accommodate the bottom mount for the lift cylinder since the loader bucket comes back far enough to hit the cylinder mount.

 

[LarJea]

With a little plumbing, and a $130 diverter valve, you already have the control wiring and buttons. Wouldnt be hard to switch to a diverted valve and use your joystick for feathering.

Up until I read these posts, I thought that was the way diverter valves were set up. On my excavator I just toggle back and forth from articulating the boom to using the thumb while using the same lever and plan on going the same way on my tractor. Probably switching back and forth with the tilt lever when using the grapple, that is unless someone knows why I can't do it this way.

 

[David_Kb7uns]

With the proper flow restrictor mounted on the attachment you will be able to have good control. Have the Long valve with a Bradco grapple. Just hitting the button gives me a closure rate on order of a decent bucket curl rate, but where the hidden benefit of this system out shines the diverter valve and the rear remote. When you learn to hit the 3rd function button while curling putting the grapple cylinders in series with the curl thus decreasing your clamping force but then the feathering control of the loader control is added and have been able to some very good work with the grapples. When carrying brush, clamping pressure is not the real issue, sometimes you need to tighten up the grip on things and tapping the control for different amounts of time will give you the desired results, this is where having the right size restrictor makes the difference.

Picking this log up below would not have been possible without the ability to curl, grapple and move forward at the same time as the weight was too much for grapple and curl functions and relied on breakout force to complete. Try doing that with a diverter only or rear remote lever that is beside you and loader control is in front.

Electric valves are able to be proportioned also, all the feller bunchers, processors and logging shovels are electronic pilotted now instead of hydraulic pilotted except on main boom functions. Even the solenoids on my Kubota GL3130 transmission are modulated.

David

 

[Luke'sScreenName]

They were installed on the T fitting where the hoses split to go to both cylinders, they aren't very big, I wasn't too sure if the dealer had removed them until I took the hoses apart from the T fitting to make sure. The instructions don't show them very well. I should be able to make a trip home in a couple weeks, if I do then I'll try to remember to post some pictures of them. It made a noticeable difference in how fast the lid opened and closed making picking up stuff much faster.

Thanks!

 

[Fallon]

You can get electronically modulated valves, but they are a lot more complex & hence expensive than the basic on/off 3rd function valve or a diverter valve.

 

[ovrszd]

I have the Kubota system with no restrictors. I can move my Grapple claws an inch or less with a bump of the switch. I guess I don't quite understand the frustration?

I'll stick with my first suggestion. Patience. Use it a couple hours. When you start piling brush and other tasks you'll be soooooo glad it's prompt.

 

[Rustyiron]

I have the Kubota system with no restrictors. I can move my Grapple claws an inch or less with a bump of the switch. I guess I don't quite understand the frustration?

I'll stick with my first suggestion. Patience. Use it a couple hours. When you start piling brush and other tasks you'll be soooooo glad it's prompt.

It just dawned on me that the OP has a hydrostatic tractor, prolly running at much higher constant rpm than we run our gear tractors with a "gas pedal". That would make it pretty "jumpy". Fxfymn, for log loading, could you get used to lowering the engine rpm's?

 

[LD1]

It just dawned on me that the OP has a hydrostatic tractor, prolly running at much higher constant rpm than we run our gear tractors with a "gas pedal". That would make it pretty "jumpy". Fxfymn, for log loading, could you get used to lowering the engine rpm's?

Thats probably the biggest thing that took some getting used to when I went from gear to HST. The constant higher RPM's, like 1500-2000, makes the loader operate real quick. Especially dump. I was banging the stops quite a bit at first. Never had an issue with the grapple because I went with a diverter.

But running the tractor a constant 2000rpm is alot different than running it at 500-600 idle and using the gas pedal to speed things up "as needed"

 

[TripleR]

HST vs gear, and operating RPM may well be an issue, but it doesn't have to be. I use a third function with an HST as well as gear with a grapple off the RR and just as with ovrszd with just a bit of use, I have no problem with the third function, just a bit different approach, but no big deal.

 

[Fxfymn]

Not only does the HST keep the engine speed up, but the Tier 4 "asks" you to run at a higher RPM as well. Of course if I do run it at a lower RPM I can instantly throttle up using the switch on the loader joy stick. If they put any more switches on the joy stick I'm going to have to have another thumb grafted onto my hand to operate them.

One thing about my configuration that may well be contributing to the issue is that my "grapple" is really more like a thumb on a backhoe. it uses a single 2" cylinder which I'm sure is one reason why it is so quick to react. As I said my first step is to restrict the flow and I'll see what happens. If not, the hoses from the rear are already in place and all I need to do is hook them to the existing hoses that run up the loader to the bucket. In fact, I may end up switching between the valves depending on what I am doing; 3rd function for brush, moving logs to the landing, etc and remotes for loading the logs into the trailer, picking up things like my auxiliary fuel tank, etc. We'll see.

It's kind of funny in a way; this is my fourth CUT and is the one I always thought I wanted. Now that I'm into it I don't know if I should have stuck with the simple old stuff.

 

[MtnViewRanch]

With your 2" dia cylinder, start out using the restrictors sized at .030. That should be good for you.

 

[Fxfymn]

With your 2" dia cylinder, start out using the restrictors sized at .030. That should be good for you.

.

Thanks, I'll give that a shot.

 

[Fxfymn]

I installed an adjustable flow limiter into the circuit and it helps, but it is still a pretty hard open and close. I'm going to try it, but I'm not impressed.

 

[MtnViewRanch]

I installed an adjustable flow limiter into the circuit and it helps, but it is still a pretty hard open and close. I'm going to try it, but I'm not impressed.

You should be able to stop the flow if you are using an adjustable restrictor. So the hard open close is not understandable. Just close the restrictor valve more.

 

[Fxfymn]

I closed it enough to keep the system operating correctly. If I close it down more one of the solenoids will not cycle off unless I operate the switch in the opposite direction.

 

[ovrszd]

I closed it enough to keep the system operating correctly. If I close it down more one of the solenoids will not cycle off unless I operate the switch in the opposite direction.

Be wary of this. When you close enough to restrict flow considerably you are placing load on your relief valve. Might hear a slight squealing when using. Same with restrictor fittings. The flow capacity of your system is going somewhere. It doesn't simply not flow. So if it's not going toward the load, it's dumping out the relief valve. Too much restriction and repeated use can cause heat in the system and stress on the relief valve.

 

[Milo]

Be wary of this. When you close enough to restrict flow considerably you are placing load on your relief valve. Might hear a slight squealing when using. Same with restrictor fittings....

So is there any good fix or remedy? Maybe a longer travel, variable switch that can be feathered instead of what I take it to be open-off-close switch? I've been following this thread as I really have use for a grapple. But I can see how the abrupt opening and close could be very aggravating.

 

[MtnViewRanch]

So is there any good fix or remedy? Maybe a longer travel, variable switch that can be feathered instead of what I take it to be open-off-close switch? I've been following this thread as I really have use for a grapple. But I can see how the abrupt opening and close could be very aggravating.

Use a diverter type valve and not have these concerns.

 

[ovrszd]

So is there any good fix or remedy? Maybe a longer travel, variable switch that can be feathered instead of what I take it to be open-off-close switch? I've been following this thread as I really have use for a grapple. But I can see how the abrupt opening and close could be very aggravating.

The restrictor devices are the best you can hope for. And they work fine if properly used. Just be careful about pinching down the flow too much.

I don't use restrictors on my Grapple. It used two 2"x8" cylinders. My M9540 has considerable flow. They can be slammed open or closed. If I'm wanting to be gentle I can "tap" the joystick buttons and regulate it pretty well. Just takes practice.

To have a Grapple is worth the learning curve of controlled use.

For clarity, understand, a diverter system uses your "curl" function on the FEL to operate the Grapple. So it has delicate control by a steady hand on the joystick. What you sacrifice is the ability to do both functions at once.

The system we're discussing here is operated by electric over hydraulic valves. They only know "open" "closed". The gain is multiple simultaneous functions.