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

 

[TWD]

Thanks rScotty!

Funny you mention the pushing it back, that's what I did once on a stump already, just hooked it and drove around to straigthen it out...

I don't mind it being random\weird but when I'm going 10mph down a 1 lane road with 200 homes and it randomly slams to the other traffic laneside that's not safe or good. I also ironically sometimes put a log in the backhoe on the left side and drive home along the road, it could be catastrophic in such instances if it auto-swings to the opposite side with a 10' 20" tree in the grips!! Yikes!

I'm going to check a bunch of stuff.

@rScotty no one swapped that m62 valve yet or what? Seems like if it's resolved that may be a way.

I did discover a leaky hose in my valves for the backhoe which explains why it's bleeding-off and my hoe is getting floppy and jerky feeling... excited to snug that up

 

[rScotty]

Reading through your explanation again, what is happening with yours does sound different from the usual, "power in one swing direction but not in the other".

For one thing, I've not ever heard of anyone else whose hoe suddenly began swinging under power all by itself. That sure is scary. Are you positive?
Of course there is a swing lock. I think if I were you I'd be using it when traveling.

I sometimes use that way of carrying a tree trunk myself. Carrying a 30 foot slender pine tree it makes me feel like Don Quixite getting set up to go tilting at trashcans....very tempting....
rScotty

 

[rScotty]

BTW, I just looked up the complete M62 replacement control valve assembly: $4K & change.

 

[TWD]

Reading through your explanation again, what is happening with yours does sound different from the usual, "power in one swing direction but not in the other".

For one thing, I've not ever heard of anyone else whose hoe suddenly began swinging under power all by itself. That sure is scary. Are you positive?
Of course there is a swing lock. I think if I were you I'd be using it when traveling.

I sometimes use that way of carrying a tree trunk myself. Carrying a 30 foot slender pine tree it makes me feel like Don Quixite getting set up to go tilting at trashcans....very tempting....
rScotty

I went out and tried on my m59, and it acts like everyone elses... I can push it back by hand or my wife pulling on it to re-center\go left, works fine! Did that a few times and now I have power (10%) to move it left, but it won't go more than a little past center to the left now, ha! I'm guessing it's the control valve. Sadly, yeah it did randomly move on me RIGHT as I hit the main road once already...

Good call on the lockout left\right, totally forgot that one existed!


Woah! $4k+, I though the M59\Stock one just under $2k was bad when I glanced.

 

[oldnslo]

Wouldn't me physically moving the lever\valve into another position test this, .

If you are moving the spool it should change what cylinder is doing.

Next step is gauges in both cylinder ports on the swing spool. Even better if you have one is a bi-directional flow meter in the line going to swing cylinder that is not swinging back. Now you can check for both pressure and flow.


Problem is flow meters are expensive and take up some space so you usually need another hose to get them into a circuit.

Other option is needle valve or flow control plus gauge between valve and flow control. You can now close the flow control and you should get system pressure. On assumption the swing reliefs are in the directional valves that would test the swing relief.

Bottom line you somehow have to isolate components to narrow down which one is failing.

What type of swing cylinder is on an M59? Two opposing single acting, two opposing double acting, vane type swing cylinder?

 

[m59owner]

You will never guess what happenned..... I joined the forum tonight because yesterday digging out a stump on a slight incline where my M59 tractor was leaning to the right. After a few movements of the backhoe it stopped responding to the left swing control input and slowly moved all the way to the right. I moved the tractor back to even ground and with the help of another person, swung it back to center and used the transport safety pin to secure it in place.

Mine is a 2014 model with just under 1,700 hours. Like others, no leaks or bad hoses. Linkage and connections all work smoothly and move as they should. Initial thought it was a control valve issue but reading some of the posts I saw it appears it is a mystery that can solve itself with some shaking and wiggling.

When I looked at the control valve diagram there is a pc in there called a poppet (#80 below). I am not sure what that is. Is that the pressure relief valve and could that get stuck in a position that lets the fluid pass one direction but not the other? If so, could that be removed, cleaned and inspected? I will try the shake and wiggle thing in the morning but was hoping for something more scientific to check. Thanks!

Found this handy flow chart below someone else posted on an old thread where you can see how the flow works for left and right swing cylinders. I think you would say they work in parallel. I suppose a cylinder seal could be an issue but seems unlikely.

 

[oldnslo]

My guess is that item 80 is the load check and not a relief valve.

I don’t see any work port reliefs in that parts break down

That hydraulic diagram shows two double acting cylinders, one extending while other is retracting so push and pull circuit.

 

[m59owner]

I found the parts diagram for the swing control valve below and it shows an overload relief valve on the top and bottom (part # 100). One for right swing and one for left swing. I had an issue 2 years ago where the boom would fall and pulling back on the stick (boom up) would raise it and letting go of the stick it would fall to the ground. I ended up swapping the lower and upper overload valves and I was able to keep working since the boom could not fall up.... I ordered a new one but have not put it in as I have not had any further boom issues.

I just checked the overload relief valve for the swing control valve, and it is different part number that the spare I have. I might try swapping the upper and lower relief valves to inspect and see what happens. I saw on another post (link HELP! My Backhoe won't swing left!) that someone had the same boom issue (falling down) and found part of the O-ring on the inside the relief valve was damaged. Kubota told them it was not serviceable, but they found a suitable Oring and said it works find now. I am getting the sense that the pilot style relief valves can be quirky. Some think it is air getting in the pilot causing it to stop working. Could my working on the side of a hill and the machine jostling around pulling on roots allowed some air in the system and shaking and wiggling the machine while tilted to the left with get the air out. Or maybe there is some contamination in the relief valve and cleaning it will do the trick. Will see.

My take from the other post I found. In the example below, if the overload relief valve on the left is stuck open for some reason, instead of fluid at pressure going out port B6, it is flowing back through the overload relief valve back to the hydraulic tank. With no fluid under pressure going out port B6, there is nothing flowing back in through port A6 as that there is no fluid being pushed out the other end of the swing cylinders. When you let go of the boom left/right stick, the load check valve (#4) should close and lock the boom in position. But with the overload relief valve stuck open, the hydraulic fluid just passed back to tank while gravity moves the boom and pushed the fluid back out through the open relief valve.

Hard to think a bubble air or a small bit of an O-ring could divert 2,700 psi of pressure even when there is no overload condition. Feels like that is where the issue is.

 

[oldnslo]

Air bubble would not cause a relief to fail but a piece of contaminate certainly will especially if that is the style of relief that also has anti-cavitation check built in. The check opens at real low crack pressure to draw oil from tank line to help keep an over running cylinder full of oil. Then if check sticks open it prevents the relief from building pressure.

 

[TWD]

If you take the valve out to check for broken gasket\o-ring please take pics as you go and share

It appears it's not too much effort, and that's my plan to tackle in the coming weekend.

Also, did you check your hydrualic fluid level? I did, mine was at the bottom line I'm going to top it off and maybe get lucky it was air in the line... probably not, but hey, worth it