Backhoe Side to Side -- Stuck?

[TWD]

I was digging a hole with my Kubota m59 Backhoe and suddenly it went to the right (when facing rear) as far as it could go, and is holding itself there touching my stabilizer.

I cannot reposition it.

I came back the next day and it had no problem, started up centered, and it stayed there for my next 1-2hr project.

Fast forward a day later I needed to go do another project and I get 100' away driving and once again it goes far right max position, and now it won't center or let me center it.

I popped off the cover to see the controls and nothing is sticking or getting hung-up that I can see.


Position sensor? Valve? Dirty Screen? I have no clue what this could be but it seems to be either "on" or "off" no in-between bleeding off causing it to slowly move.

 

[loggin]

I was digging a hole with my Kubota m59 Backhoe and suddenly it went to the right (when facing rear) as far as it could go, and is holding itself there touching my stabilizer.

I cannot reposition it.

I came back the next day and it had no problem, started up centered, and it stayed there for my next 1-2hr project.

Fast forward a day later I needed to go do another project and I get 100' away driving and once again it goes far right max position, and now it won't center or let me center it.

I popped off the cover to see the controls and nothing is sticking or getting hung-up that I can see.


Position sensor? Valve? Dirty Screen? I have no clue what this could be but it seems to be either "on" or "off" no in-between bleeding off causing it to slowly move.

I don't know your particular machine very well but I do not believe there are position sensors for the backhoe's hydraulic cylinders. We would also need more information as to the behavior of the backhoe when this happens. What inputs were given when this happened, did the other cylinders still work? Did it sound like the pump was under load? Are the quick connects seated properly? A video would likely be best showing multiple operations while this is happening.

 

[TWD]

I don't know your particular machine very well but I do not believe there are position sensors for the backhoe's hydraulic cylinders. We would also need more information as to the behavior of the backhoe when this happens. What inputs were given when this happened, did the other cylinders still work? Did it sound like the pump was under load? Are the quick connects seated properly? A video would likely be best showing multiple operations while this is happening.

1. There is no pump sound, no humm or usual sound... like if my thumb foot pedal is stuck.
2. All other backhoe functionality work 100% fine, aside from the ability to go left\right, since it is stuck in far right position.
3. Problem is not 100% all the time, it comes and goes.
4. The only thing that occurs is the the backhoe will randomly go full right position, and hold there not allowing me to correct it. Sometimes turning off and on and it works again until it happens again.
5. I noticed several months ago it would creep\turn to the right slightly, but not often and not the whole way and not disallow me to center it \ go left.
6. It's acting as if I'm holding the lever to the right, trying to get it to go right, bu no matter what I do with that lever (go left, go up down left, etc, etc, it does not go back left).. I can raise and lower just fine though with the same lever but using the other positions (push pull vs left\right).
7. I did pop off the backhoe connectors on the tractor and reconnect them, still occurred.
   
   
   To me it's acting as-if something in the valve that's controlled by the lever is not closing, the rate at which it's moving also indicates it's not open 100%. The lack of any pump\fluid sound is odd though... then again these cylinders are tiny relative to the rest of the tractors so there may never be any pump sound going left\right.

 

[loggin]

1. There is no pump sound, no humm or usual sound... like if my thumb foot pedal is stuck.
2. All other backhoe functionality work 100% fine, aside from the ability to go left\right, since it is stuck in far right position.
3. Problem is not 100% all the time, it comes and goes.
4. The only thing that occurs is the the backhoe will randomly go full right position, and hold there not allowing me to correct it. Sometimes turning off and on and it works again until it happens again.
5. I noticed several months ago it would creep\turn to the right slightly, but not often and not the whole way and not disallow me to center it \ go left.
6. It's acting as if I'm holding the lever to the right, trying to get it to go right, bu no matter what I do with that lever (go left, go up down left, etc, etc, it does not go back left).. I can raise and lower just fine though with the same lever but using the other positions (push pull vs left\right).
7. I did pop off the backhoe connectors on the tractor and reconnect them, still occurred.
   
   
   To me it's acting as-if something in the valve that's controlled by the lever is not closing, the rate at which it's moving also indicates it's not open 100%. The lack of any pump\fluid sound is odd though... then again these cylinders are tiny relative to the rest of the tractors so there may never be any pump sound going left\right.

Typically when the cylinder hits it's limit the pressure relief valve opens up and you can usually hear that and the sound of increased load on the pump. It could be the spool valve but it might also be the cylinder rod seal.

 

[loggin]

1. There is no pump sound, no humm or usual sound... like if my thumb foot pedal is stuck.
2. All other backhoe functionality work 100% fine, aside from the ability to go left\right, since it is stuck in far right position.
3. Problem is not 100% all the time, it comes and goes.
4. The only thing that occurs is the the backhoe will randomly go full right position, and hold there not allowing me to correct it. Sometimes turning off and on and it works again until it happens again.
5. I noticed several months ago it would creep\turn to the right slightly, but not often and not the whole way and not disallow me to center it \ go left.
6. It's acting as if I'm holding the lever to the right, trying to get it to go right, bu no matter what I do with that lever (go left, go up down left, etc, etc, it does not go back left).. I can raise and lower just fine though with the same lever but using the other positions (push pull vs left\right).
7. I did pop off the backhoe connectors on the tractor and reconnect them, still occurred.
   
   
   To me it's acting as-if something in the valve that's controlled by the lever is not closing, the rate at which it's moving also indicates it's not open 100%. The lack of any pump\fluid sound is odd though... then again these cylinders are tiny relative to the rest of the tractors so there may never be any pump sound going left\right.

Sorry, hit the reply a little too soon. When I said rod seal I meant the piston seal at the end of the rod. There are ways to test that but not sure if you feel comfortable in doing that..?

 

[loggin]

Testing requires disconnecting and applying pressure to certain hydraulic circuits at very high pressures. Not something you want to try unless you are comfortable with that.

 

[oldnslo]

I would triple check to make certain that swing valve spool is spring centering properly all the time. Not common occurrence but centering spring assembly under the can can work loose on some valve designs causing weird operation. You should be able to tell by the amount of spool exposed on the linkage connection end.

 

[jfsawatzky]

When you took off the cover did you check the end of the levers where it connects to the valve in case the portion that slides in and out of the valve is sticking?

 

[TWD]

I would triple check to make certain that swing valve spool is spring centering properly all the time. Not common occurrence but centering spring assembly under the can can work loose on some valve designs causing weird operation. You should be able to tell by the amount of spool exposed on the linkage connection end.

Wouldn't me physically moving the lever\valve into another position test this, or no?

When you took off the cover did you check the end of the levers where it connects to the valve in case the portion that slides in and out of the valve is sticking?

I didn't notice anything, but with your suggestion I'll take again and take pic to share.

 

[rScotty]

I was digging a hole with my Kubota m59 Backhoe and suddenly it went to the right (when facing rear) as far as it could go, and is holding itself there touching my stabilizer.

I cannot reposition it.

I came back the next day and it had no problem, started up centered, and it stayed there for my next 1-2hr project.

Fast forward a day later I needed to go do another project and I get 100' away driving and once again it goes far right max position, and now it won't center or let me center it.

I popped off the cover to see the controls and nothing is sticking or getting hung-up that I can see.


Position sensor? Valve? Dirty Screen? I have no clue what this could be but it seems to be either "on" or "off" no in-between bleeding off causing it to slowly move.

It sounds like a variation on the side-swing malfunction that is a known problem with the M59.
Someone good with a search program could find us dscussing odd side swing behaviour as far back as the original M59 Discussion Thread (46 pages, 2008 to 2017). The interrupted or unpowered swing has been discussed many times since. It is sometimes a little different. Your example of it being stuck all at one side seems a little different.

M59 Discussion Thread​

No one has yet come up with a good explanation why the M59 backhoe will sometimes either stop swinging in one direction or hang up half way through the swing. But they certainly do those things. We aren't talking about a mechanical problem....there have been a few of those as welll - things like broken or disconnected pistons, but the "hanging interrupted swing" is different.

The interrupted swing only has power in one direction. The hoe will only power swing in one direction. Lots of theories, but nothing definite so far. Most M59 owners have experienced it. The hoes will swing under full power in one direction but not at all in the other direction. The problem comes on for no reason and then goes away just as mysteriously.

It will sometimes happen twice in a month and then not again for ten years. My own opinion is that it is a defect or dirt in the paired swing relief valves that causes the control valve to bypass in one direction but not the other.

Symptoms are when you work the control lever it is normal in one direction and nothing in the other. When calling for it to swing the other way, everything feels and sounds normal but there is no power to make it move. However, if the lever is held over in the unpowered direction, you may find that a helper can easily push the hoe over in the unpowered direction. And that "one way power and one way free" motion is just curious enough that it lead us to devise a way to fix the problem...this all happened back around 12 years ago. It's led to a trick that has worked now for several M59 owners.

The trick is to power the boom all the way to the side, then raise the outrigger on that side. Now using gravity to swing the boom back to the low side, while it is moving you work the control lever causing the backhoe to LIGHTLY bounce during the gravity swing. Repeat again and again...Doing that puts a hydraulic pressure wave through part of the control valve circuit & may flush some obstruction or stickiness out of the relief valve. Do that a few times and see if the function returns. It's worth a try.

I noticed a while ago that the M62 has redesigned that entire relief valve section of the backhoe control valve. I wonder if that is the reason?
Luck,
rScotty