Grapple won't open!!! Kubota M8560 3rd Function Valve or Hydraulic lock?

[markjm]

Hi All,
First post here because I am desperate and my dealership are not able to cast any light on this topic. I have a new Kubota less than 12 months old and the grapple quit working properly. I had the factory 3rd function valve kit installed when I bought the tractor and it has worked flawlessly until now. It appears that there is pressure going into the grapple but it will not open. Here are some things I have done so far to get this thing to open:

1) I topped up the hydraulic fluid...it was a little low but this didn't help.
2) I cracked all the hoses at the grapple and on the backside of the FEL 3rd function connectors to relief any hydraulic lock pressure. Still won't open.
3) I removed the grapple hoses completely and relieved pressure in them then reinstalled...still won't open.
4) I operated the grapple and can hear the valve screeching and applying pressure to close the grapple so I know that pressure is getting down there.
5) When I press the open trigger though I hear nothing which leads me to suspect there is something wrong with the 3rd function valve...maybe the solenoid?

I cannot leave this post without telling you that I did have to replace the left hand side grapple cylinder which was sticking due to a bent rod. It worked for a couple hours after the incident and then the grapple quite opening. So I don't know if this is related? This is why I cracked all the hoses cause I was thinking I created some kind of lock in the system. Regardless however I have replaced the defective cylinder and still the grapple will not open.

Does anyone have any ideas? Is this something I can "jimmy"...as in tap on the solenoid (I have no idea where it is).

Do I need to bleed the system somehow?

Is there another reason why I wouldn't hear the valve opening and the screeching noise?

I am desperate for help and had planned to use the grapple all weekend to clear some land. Thank you in advance gentlemen.

Mark

 

[nybirdman]

Sounds like the solenoid is stuck(for the third function).May be a detent to push to "center".Try tapping of the solenoid with the pressure off.

 

[markjm]

Sounds like the solenoid is stuck(for the third function).May be a detent to push to "center".Try tapping of the solenoid with the pressure off.

Thank you I will try that once I figure out where the solenoid is exactly

I am changing out all the QD's on the hoses and on the tractor side to eliminate those. Will report back, thanks!

 

[markjm]

I changed out all the quickconnects and also swapped the hoses over to see what would happen. Now the grapple opens up but will not close. So there is a problem with the 3rd function valve for sure.

Anyone know how to locate this valve on an M8560? I thought I heard someone say it was under the floorboards?

 

[nybirdman]

You should be able to trace the lines back;my third function on my L4240 is on the right side below the cab door,on the side of the tractor.

 

[DT86]

All the valves for the loader will be behind and down from where the loader lines connect to the tractor.

But, a machine that new, I'd be pestering the dealer for answers. If they can't help I'd move on to corporate.

 

[rScotty]

I changed out all the quickconnects and also swapped the hoses over to see what would happen. Now the grapple opens up but will not close. So there is a problem with the 3rd function valve for sure.

Anyone know how to locate this valve on an M8560? I thought I heard someone say it was under the floorboards?

just
Good thinking! I was about to suggest trying that very thing when you posted. Good thinking, Markjm. That eliminates the cylinder and seems to implicate the solenoid. Maybe it's just got some crud in the solenoid. With luck it could even be the wires to the solenoid or the solenoid switch. I'd probably try to check those out first.

I gotta say that Kubota is right there with a lot of other modern tractors in putting serviceable components into places where they are hard to get to. Maybe they will change that philosophy. Hopefully access is better on the larger 8560. On our M59, the floor boards are welded down instead of bolted. Makes the machine marginally stiffer, a tiny bit cheaper, and the very devil to get to things like solenoids if needing service - or evengetting to cables needing lubed. If the floorboards were bolted or access ports provided, that sort of service would be easy.
Good luck; keep us posted.
rScotty

 

[SDT]

Hi All,
First post here because I am desperate and my dealership are not able to cast any light on this topic. I have a new Kubota less than 12 months old and the grapple quit working properly. I had the factory 3rd function valve kit installed when I bought the tractor and it has worked flawlessly until now. It appears that there is pressure going into the grapple but it will not open. Here are some things I have done so far to get this thing to open:

1) I topped up the hydraulic fluid...it was a little low but this didn't help.

About a month ago I took delivery on a new M9960. I, too specified a third function valve for use with a grapple bucket and FEL mounted, hydraulic angle snow plow.

Firstly, I like the Kubota third function system better than that used by CNH, MF, etc, because it is independent of the joy stick.

I'm a
2) I cracked all the hoses at the grapple and on the backside of the FEL 3rd function connectors to relief any hydraulic lock pressure. Still won't open.
3) I removed the grapple hoses completely and relieved pressure in them then reinstalled...still won't open.
4) I operated the grapple and can hear the valve screeching and applying pressure to close the grapple so I know that pressure is getting down there.
5) When I press the open trigger though I hear nothing which leads me to suspect there is something wrong with the 3rd function valve...maybe the solenoid?

I cannot leave this post without telling you that I did have to replace the left hand side grapple cylinder which was sticking due to a bent rod. It worked for a couple hours after the incident and then the grapple quite opening. So I don't know if this is related? This is why I cracked all the hoses cause I was thinking I created some kind of lock in the system. Regardless however I have replaced the defective cylinder and still the grapple will not open.

Does anyone have any ideas? Is this something I can "jimmy"...as in tap on the solenoid (I have no idea where it is).

Do I need to bleed the system somehow?

Is there another reason why I wouldn't hear the valve opening and the screeching noise?

I am desperate for help and had planned to use the grapple all weekend to clear some land. Thank you in advance gentlemen.

Mark

I'm a believer in bleeding hydraulic systems that are not close to the pump and sump. Long ago I built a "bleed hose" to do just this. It is simply a 36" hydraulic hose with connectors on each end that connect to the third function connections on the FEL. Simply connect the bleed hose and operate the third function system in both diretions for a bit to ASSURE that there is no air in the long lines. Regardless of what you are told, if there is air in the system far away from the pump and sump (there will be if your dealer does not do as I do and none do upon assembly) it will NOT bleed itself and the system will be forever spongy.

That said, I doubt that air in the system is your problem. It sounds like you have the lines reversed on the cylinder that you replaced. Does operating the third function system load the engine (dead headed system)?

SDT

 

[MinnesotaEric]

Trace the hydraulic lines from the loader's third function until you fine a valve. If a diverter valve, you may have it mounted on the loader itself or the valve may be mounted under the cab. All of these valves use relays. You may want to locate the relay and swap it with another one in case the stupid relay is stuck on.

When I made my third function for my Kioti, I used solid state relays in order to increase the reliability.

 

[MHarryE]

I had a problem somewhat similar to yours and it turned out to be something about the couplers. I could never figure out what was wrong with the set that came with the attachment. What made me think of this is when you said you got the grapple to open but it wouldn't close. I had similar luck. With one swap I got the cylinder to extend but then it wouldn't retract so I bought a name brand set of couplers instead of ones only marked "China" and it has worked fine. My next problem is I didn't throw the bad ones away and had a similar problem when I picked them out of my parts bin.