third function value help with Kubota

[cattlefarmboy]

I have a Kubota 5140 with a third function value installed by the dealer and a Dirt-dog grapple. When using the grapple, it can be open and the tractor is off then the grapple will start to close on it self. It the same if you are using it with a load and it will start to back off. I have talk with dealers and techs about it and they all have passed it off with being normal. I know that is not right cause you wont have a trackhoe thumb start losing a load on the job site. What could be the problem with the value or hydraulics. It not the grapple seals leaking, i talk with a company tech to check the seals by disconnect the hydraulic and try to move it back and forth. Could it be trash in the value? I'm just tried of bumping the button all the time.
Thanks, James

 

[J_J]

To check the valve, open the grapple and shut the engine off.

Since the cyl is supposed to be locked with the valve in neutral, the grapple should not move.

Remove the IN hose and the OUT hose from the 3rd function. If the grapple falls/closes, then you will see fluid flowing from either port that means that the valve spools are leaking.

If the grapples falls and no fluid flows out the valve, then the cyl piston seals are leaking.

You might also inspect and clean the valve relief.

You could also switch hoses from the curl/lift to the grapple to see if the grapple will hold.

 

[bandaidmd]

Your third function is an electrically controlled splitter ?

The curl and dump hold position like they should if not using the "button" ?

My third function is a electrically controlled diverter valve plumbed to the curl to close the lid and once pressure is applied to the lid it holds until i press the toggle switch and move the lever to open it.

 

[beemerphile]

My M5040 has a Dirt Dog grapple and a Kubota OEM 3rd function valve. Mine does the same thing. It leaks down even with the machine running. It is a hassle and I would be interested as well in a cure. I just had the valve off the tractor for other reasons. Mine is a double solenoid electric valve and comes ahead of the loader in hydraulic power sequence. It has a power on/off switch and momentary raise and lower buttons on the loader joystick handle.

I am about to replace the Dirt Dog grapple, so I guess it will answer one question depending on whether the new grapple does it too. I also have a 4-n-1 bucket for the machine but I haven't used it enough to know if it drops like the grapple does.

 

[J_J]

Then your valve or cyl is leaking.

Temporarily switch the lift circuit hose to the grapple and see if the grapple will hold.

Why is your grapple hyd circuit before your loader?

That means that when you are using the grapple, nothing else in the circuit is getting any fluid.

Did the dealer install it that way?

 

[cattlefarmboy]

So it still a problem with it somewhere. It will be this weekend before I can even look into it. I was thinking at one time metal shavings could have gotten in it cause of being brand new.

 

[paulwestski]

Then your valve or cyl is leaking.

Temporarily switch the lift circuit hose to the grapple and see if the grapple will hold.

Why is your grapple hyd circuit before your loader?

That means that when you are using the grapple, nothing else in the circuit is getting any fluid.

Did the dealer install it that way?

That's how the Kubota OEM 3rd function is plumbed, the sub plate has a relief built in.

 

[J_J]

It would seem logical to install the 3rd function valve after the PB on the loader valve.

Then it would not interfere with the loader operation.

Does it work better/not for those that have the valve ahead of the loader?

 

[J_J]

This is a reply from the guys at Messicks.

JJ

I spoke to our service dept...The solenoid for the 3rd function is mounted on a block for the bucket cylinders. It is fed from the loader valve. If your grapple is leaking down, the problem could be in the solenoid valve or internal in the grapple cylinder.

 

[beemerphile]

This is a reply from the guys at Messicks.

JJ

I spoke to our service dept...The solenoid for the 3rd function is mounted on a block for the bucket cylinders. It is fed from the loader valve. If your grapple is leaking down, the problem could be in the solenoid valve or internal in the grapple cylinder.

My 5040 is not, and I imagine the 5140 is the same. I looked in the 1153 loader installation manual and the hydraulic flow is shown exactly as mine is installed... Pump > 3rd Function > Loader valve > rear hydraulics (lift and remotes).

 

[ovrszd]

I installed my Kubota OEM 3rd function using the kit supplied. Since the hoses were also supplied it was almost impossible to mess it up.

My 3rd function is fed from the loader valve PB. My 3rd function PB port feeds my 3pt.

My Grapple gets fed after the loader. I have enough flow with my tractor that I can use all three functions at once. The 3rd function being the slowest and having the least power while the loader functions are activated.

I can park my tractor with Grapple open and it never closes. I can also grip a large log and carry it or block it while the Grapple is holding it with no bleed off. The only time I have to repeat the grip on something is if carrying loose brush that compresses as it's carried. In that case might have to bump the close button once in a while to tighten grip.

 

[bandaidmd]

I installed my Kubota OEM 3rd function using the kit supplied. Since the hoses were also supplied it was almost impossible to mess it up.

My 3rd function is fed from the loader valve PB. My 3rd function PB port feeds my 3pt.

My Grapple gets fed after the loader. I have enough flow with my tractor that I can use all three functions at once. The 3rd function being the slowest and having the least power while the loader functions are activated.

I can park my tractor with Grapple open and it never closes. I can also grip a large log and carry it or block it while the Grapple is holding it with no bleed off. The only time I have to repeat the grip on something is if carrying loose brush that compresses as it's carried. In that case might have to bump the close button once in a while to tighten grip.

So the factory valve is always pressurized and uses solenoids instead of levers to select which port opens. I think i like that set up.

 

[J_J]

Nothing is pressurized until a cyl develops the pressure.

In an open center hyd system, fluid is always flowing through all series connected valves.

 

[ovrszd]

So the factory valve is always pressurized and uses solenoids instead of levers to select which port opens. I think i like that set up.

It uses solenoids, opened/closed by two buttons on the joystick. When neither button is pushed the fluid goes to PB.

As JJ said, there's no pressure until the flow meets resistance. So when neither solenoid is closed flow continues to the next item in line, which in my case is 3pt/rear remotes

Hmmmmm,,, now I had to think about this a little. bandaidmd, I think your interpretation is accurate. I think you understand what's happening. Just that hydraulic guys like JJ think differently than we do so his interpretation of pressurized is different than possibly ours. :thumbsup:

With a diverter valve system one or the other is susceptible to pressure/flow, but never both at once.

 

[J_J]

If you have a double solenoid valve, it will have 4 ports, and work the grapple when the button is selected.

If your valve has 6 ports, it is a diverter valve and uses the curl circuit for hyd.

I just can't see any 3rd function valve or diverter valve installed before the loader. The service guys from Messicks says it isn't so.

So someone is saying that the pump flow goes into the 3 function valve first. Show me some pictures. Please.

 

[beemerphile]

I just can't see any 3rd function valve or diverter valve installed before the loader. The service guys from Messicks says it isn't so.

So someone is saying that the pump flow goes into the 3 function valve first. Show me some pictures. Please.

"Someone" pulled this from his loader manual and the hose routing matches what is installed on "Someone's" machine. "Someone's" machine has the self-leveling valve. Unlike the standard valve, the self-leveling valve is supplied (the pump port) from the bottom. The PB (nearest) and tank (rear most) ports are both on top. The pressure line runs from pump to block inner port to 3FV to loader to block outer port to rear of machine. The instructions assume that one is adding the 3FV to an existing loader installation. The instructions say to disconnect the pump line hose. Figure 4 shows Hose (1) running from the pump block to the inlet of the 3FV. Hose (2) runs from the PB of the 3FV to the inlet (pump port) of the loader valve (where the pump line was removed in the above instruction). The PB line from the loader valve to the pump block is unchanged. The tank lines are merged.