Question about third function valve

[Michael In Tennessee]

Your dealer definitely screwed up the installation. However, these kits do not address the added complication of having a backhoe loop. The kit might not have the correct hoses but is otherwise fine.


Basically, the 3rd function is placed in series between the loader valve and the 3pt hitch in a normal installation. With the backhoe, the order will be: Loader - 3rd function - backhoe - 3pt. Note that the 3pt is likely behind a manifold under the left side of the tractor if it is anything like the bigger tractors.

The dealer needs to attach the P port of the 3rd function to the existing loader power beyond port and move the existing power beyond hose to the T port of the 3rd function. Use whatever adapter fittings are needed to get a clean install. There are no extra quick disconnects required, nothing ever needs to be connected/disconnected except your normal backhoe loop when you don't have the backhoe connected. The backhoe PB hose might not be the correct length and you might have to get a custom hose made. If the hose is too long, you can either have it shortened or find a place to coil the extra. If too short, well...it ain't gonna stretch.

You will then have use of the 3rd function at any time.

If they pick up the tractor, make sure to have the grapple installed so they can test the system end-to-end.

 

[sander925]

The tractor was returned yesterday. With apologies for not getting it back a day sooner. The delivery guy was off Thursday.

I spoke with the mechanic, he stated that we had to use the backhoe loop to feed the third function valve. I asked about plumbing the third function valve in series behind the loader valve. He said that Kubota does a good job with steel lines on this particular tractor. He didn't want to cut any steel lines or do anything crazy until the warranty expires.

I haven't really looked at it yet. It is what it is. The tractor is back working correctly and I already love the grapple.

Thanks for the replies and suggestions.

Randy

 

[Michael In Tennessee]

Please clarify: do you have to unplug the backhoe and plug in the 3rd function of do they work at the same time?

 

[sander925]

I can plug them in series and use both. The mechanic said that the lines to the loader and backhoe circuits are steel coming off the pump.. I have a better understanding of what the situation is according to the mechanic. I am going to spend some time tomorrow or Monday doing some maintenance. I am going to trace all of the lines to see if what he explained is accurate. I don't know why it wouldn't be but for my own peace of mind.

 

[ericm979]

If the BH is plumbed after the 3rd function, don't use the 3rd function with the BH hooked up. BH valve stacks often are not able to handle the pressure that would generate.

 

[LD1]

If the BH is plumbed after the 3rd function, don't use the 3rd function with the BH hooked up. BH valve stacks often are not able to handle the pressure that would generate.

I think you have that backwards.

Backhoe valves typically don't have power beyond, so they are last in line....and feed nothing after them except the 3ph (which can't be used when backhoe is on)

Up street has no effect. The issue would be if the 3rd function were AFTER the backhoe valve.....causing whatever pressure it takes to operate grapple to pressurize the T port of the backhoe.

This dealer isn't giving be a good feeling. Don't want to mess with hard piping???? I'm betting it's a hose that comes off the PB port on the loader.

That is the ONLY hose that needs messed with. Simply remove it....it now feeds the 3rd valve....the the outlet of the third goes to where it went. Do post some pics or a diagram of how they have it.....but I fear you are dealing with an incompetent service department

 

[ericm979]

Yep you're right, I explained that backwards. It sounds like the OP's dealer could have put the 3rd function after the BH stack, which could damage the BH valves.

 

[bdhsfz6]

It likely isn't a factor here but FWIW, my Kubota dealer much prefers the W&R Long 3rd function valve over the Landpride. I'm not sure why since I've heard of no issues with the Landpride product. I originally ordered LP valves on both my tractors but he talked me into the W&R Long instead. The price was about the same so I went with his recommendation.

 

[Tinhack]

I guess I'm missing something. What's the BH have to do with a grapple? And why complicate the installation?

I intercepted the curl hoses with a selector valve on the Kenbota. Two hoses in, four hoses out. Push a button for grapple, release button for curl.

 

[LD1]

I guess I'm missing something. What's the BH have to do with a grapple? And why complicate the installation?

I intercepted the curl hoses with a selector valve on the Kenbota. Two hoses in, four hoses out. Push a button for grapple, release button for curl.

You have a diverter. Totally different plumbing than a 3rd fundtion. As you arent effecting any of the other valves on the tractor. You are simply diverting the curl flow of an existing valve.

A true 3rd function is another valve in series with all the rest. Typical installation goes like

Pump > Loader valve > Third function > Backhoe > 3PH

That is the order. IF you dont have one of those, just omit it and the order remains the same.

But on a conventional manual valve with cast case.....like your loader valve or the backhoe valve.....IF it is feeding valves down stream of it, it requires power beyond. You cannot simply plumb from the tank port of one valve to feed the inlet port of the next valve. The Tank port is not designed for high pressure and can/will blow out the seals that seal the spool to the casing.

The electric solenoid 3rd function valves are different as their TANK ports are usually rated high enough to handle the pressure of the downstream valves. So in my flow chart.....allowing the Tank port of the 3rd function to carry on and feed the backhoe inlet or the 3ph inlet is acceptable.

Now the backhoe valve does NOT have a high pressure rated tank port....and they are usually NOT power beyond valves either. Which is ok because the ONLY thing that is supposed to be fed AFTER the backhoe valve is the 3PH. Which cannot be used with a backhoe on anyway, and most manufactures but a disclaimer in the manual to leave the 3PH lever all the way down and not move it, because if you move it all the way to the top....and your feedback rod isnt adjusted perfectly....there is a chance the 3PH could deadhead at the top of its stroke and blow out the backhoe valve since its tank passages arent rated for pressure.

The OP's issue is the fact that they have the (or we assume to this point) the 3rd function coming AFTER the Backhoe. Which is bad news is he Closes the grapple to maximum pressure. IT will sooner or later blow the seals out of the backhoe valve.

IF this is the way the dealer installed it, they screwed up. But still awaiting conformation or pictures of exactly how its plumbed.

If the backhoe is disconnected, and the hoses just looped back together then there is no worries at all. But with the backhoe on, I wouldnt be using the grapple.