NX6010 suction side hydro leak

[YLee Kioti]

Thanks for all the info.
Since I retired , no longer have access to Grainger or McMaster books.
Yeah, I know (on-line) but really am old school and like books....lol.....
However, this is on my (long) list of wannah do's ....:thumbsup:

 

[Overtaxed]

Get a new pump

Working on it. Gotta get Kioti to authorize the dealer to do the work (warranty). However, the dealer is thinking pump too, so at least we're all in the same zip code. The thing I can't figure, how is the pump causing the "foam" you see on suction line? Or is it just foaming it up while pumping it and then the foam I see if actually from the pressure side getting returned into the tank foamy and then sucked back up? As soon as he told me there was foam on the suction side, I was thinking Orings/seals and maybe the pickup. Cause that seems like, from the original title of this thread, a suction side air leak. Either way, seems we're all thinking the same thing, time for a new pump.

does your power steering studder at all too?

Yes, it does. I didn't show it in the video because you can't see it visually, but you can feel that noise in the wheel just like you saw in the 3pt.

Any ideas why the problem pretty much goes away when the machine gets totally warm? I know we're all guessing, but my guess is something that's letting air get into the mix before full compression in the pump that eventually, when it's warm (the pump) seals up. Would also explain why this problem has gotten progressively worse, whatever it is that the heat is sealing up is getting too big to take up with the expansion of the joints.

 

[xcgreene]

Working on it. Gotta get Kioti to authorize the dealer to do the work (warranty). However, the dealer is thinking pump too, so at least we're all in the same zip code. The thing I can't figure, how is the pump causing the "foam" you see on suction line? Or is it just foaming it up while pumping it and then the foam I see if actually from the pressure side getting returned into the tank foamy and then sucked back up? As soon as he told me there was foam on the suction side, I was thinking Orings/seals and maybe the pickup. Cause that seems like, from the original title of this thread, a suction side air leak. Either way, seems we're all thinking the same thing, time for a new pump.



Yes, it does. I didn't show it in the video because you can't see it visually, but you can feel that noise in the wheel just like you saw in the 3pt.

Any ideas why the problem pretty much goes away when the machine gets totally warm? I know we're all guessing, but my guess is something that's letting air get into the mix before full compression in the pump that eventually, when it's warm (the pump) seals up. Would also explain why this problem has gotten progressively worse, whatever it is that the heat is sealing up is getting too big to take up with the expansion of the joints.

I suppose the most interesting thing to me is that both of the hydraulic pumps have failed. I suppose that points to particular causes of the failure. Other than the hydraulic pumps being bad, the only other possibility on my mind would be return fluid from the joystick valve or power steering unit. Depending on your tractor, both these return fluids from these two systems are routed not to the sump, but to the suction side of the hydraulic pumps. Meaning, that if the joystick valve relief, or the power steering relief were to be chattering with issues, foamed oil could be generated quickly by the immediate re circulation. As things warm up, the valves seat properly.

You will have to look at your particular tractors hydraulic diagram to know if this is possible, as not all tractors are this way. But as an example, here is a diagram of a tractor that has this type of setup.


It wouldn't be too much trouble ruling that possibility out with some basic knowledge. Finding the relief valves and simply feeling them for flow/noise while your issue is under way.

My money is still on bad pumps, but I think this is a possibility worth looking into.

 

[Overtaxed]

Not sure I know enough to read this correctly, but it looks like the 1/2 pumps are ganged together. Perhaps someone else can provide more details here?

 

[xcgreene]

Not sure I know enough to read this correctly, but it looks like the 1/2 pumps are ganged together. Perhaps someone else can provide more details here?

View attachment 578859

Yes, its called a Tandem pump, as you can see in your drawing, pump #1 services your loader valve, then your 3pt hitch, pump #2 services your modulator valve for the pto, 4wd clutch, power steering, and then onto your Hst. If this is your tractors drawing, I can see that the particular situation I was mentioning earlier is not quite possible, as there are no immediate re circulation lines at play here.

Here you can see the pumps exploded view

 

[Overtaxed]

Yes, its called a Tandem pump, as you can see in your drawing, pump #1 services your loader valve, then your 3pt hitch, pump #2 services your modulator valve for the pto, 4wd clutch, power steering, and then onto your Hst. If this is your tractors drawing, I can see that the particular situation I was mentioning earlier is not quite possible, as there are no immediate re circulation lines at play here.

OK, makes sense, I wondered why I couldn't find the "other" pump, they are all in one housing. Learning something new. Anyway, yes, the way I read that diagram, it's pretty much a straight shot from the sump to the pump(s). The only thing in between is the hydro filter, which, of course, is where I thought for sure I'd find the problem (especially the soft connection that I showed in the video). The dealer thought "chattering valve" too initially, but I suspect when he looked closer at the flow diagram, that was ruled out because there's no where for air to get in the suction because of the valve, they are all on the pressure side and return to the sump; a leak would be a stream of fluid, not air sucking in, right?

And yes, this is the drawing for my tractor, it's from my service (the big one) manual.

 

[Coyote machine]

FWIW, if it were my tractor all I'd be concerned about is getting my dealer and Kioti corporate on the same page about the fix and implementing same. Pages of speculation about why and how the pump(s) work or don't, fixes nothing, and may lead to a misleading approach to the eventual fix.

Prior HST system failures are well documented in the Kioti owning/operating section. Though few and far between occasionally a faulty pump/system will get past QC and end up at retail level needing a replacement.

The NX series is relatively new so such issues are not that common as prior HST model Kiotis.

 

[AWSubie]

I noticed you have either third function or diverter valve for the loader and a top hydraulic link for the 3 point. Were these items on the tractor since new or did you add them later? Did the pump noise start around the time that either of these items was installed? Just curious if a hydraulic line routing may not have been correctly installed.

 

[Overtaxed]

I noticed you have either third function or diverter valve for the loader and a top hydraulic link for the 3 point. Were these items on the tractor since new or did you add them later? Did the pump noise start around the time that either of these items was installed? Just curious if a hydraulic line routing may not have been correctly installed.

The 3rd function was installed at purchase, it's always been there. The hydro top link is new, but didn't seem to impact for better or worse the issue. Thing is, I don't see I can be getting air in the pressure side of the system, it's 2000 PSI fluid, how on earth is air going into that and fluid not coming (shooting) out? Which is why, for a long time, I've thought this was a suction side problem. The dealer, however, was thinking that too until he put the clear hose on, that, in his mind, made is clear there's something on the suction side that's not right. His first thought was a problem in the loader valve, but he's moved away from that and focused elsewhere for now. The next thing to try is a new filter housing, apparently there was a problem with a few of them that had external restrictions in them, not sure why that would cause air to get into the system, but it's what Kioti wants to try next. My money is on hydro pump, I've just had too much hydro weirdness with this machine from day 1 (that, because I'd never used a hydro before I attributed not to the machine, just to hydro static drives, but, now with another hydro in the family, I can see that this was "never right", at least not if Kioti's hydro operates anything like JD for smoothness).

I actually have the tractor back, it's a mess much worse than it was before, but I suspect that's mostly because it's gotten cold. This issue is nearly 100% temperature dependent. In warm weather, it'll never make the noise you hear on the video and the hydro behaves "not bad" (again, not as good as I think it should). I went out to use the tractor the other day, it was about 30 degrees out and I had to let it warm up for 30 minutes before it would reliably move the loader. It sounded awful, just bubbles all over in the suction line.

Interestingly, when it "smooths out" (from the operator perspective) and you look at the clear line, it's pure foam. Looks like the top of a latte. But I guess because it's a consistent foam, it works OK as hydro oil? Donno.

 

[xcgreene]

The 3rd function was installed at purchase, it's always been there. The hydro top link is new, but didn't seem to impact for better or worse the issue. Thing is, I don't see I can be getting air in the pressure side of the system, it's 2000 PSI fluid, how on earth is air going into that and fluid not coming (shooting) out? Which is why, for a long time, I've thought this was a suction side problem. The dealer, however, was thinking that too until he put the clear hose on, that, in his mind, made is clear there's something on the suction side that's not right. His first thought was a problem in the loader valve, but he's moved away from that and focused elsewhere for now. The next thing to try is a new filter housing, apparently there was a problem with a few of them that had external restrictions in them, not sure why that would cause air to get into the system, but it's what Kioti wants to try next. My money is on hydro pump, I've just had too much hydro weirdness with this machine from day 1 (that, because I'd never used a hydro before I attributed not to the machine, just to hydro static drives, but, now with another hydro in the family, I can see that this was "never right", at least not if Kioti's hydro operates anything like JD for smoothness).

I actually have the tractor back, it's a mess much worse than it was before, but I suspect that's mostly because it's gotten cold. This issue is nearly 100% temperature dependent. In warm weather, it'll never make the noise you hear on the video and the hydro behaves "not bad" (again, not as good as I think it should). I went out to use the tractor the other day, it was about 30 degrees out and I had to let it warm up for 30 minutes before it would reliably move the loader. It sounded awful, just bubbles all over in the suction line.

Interestingly, when it "smooths out" (from the operator perspective) and you look at the clear line, it's pure foam. Looks like the top of a latte. But I guess because it's a consistent foam, it works OK as hydro oil? Donno.

Be careful running with foamed up oil as bad as this, lubrication properties are greatly diminished. This def sounds more of an aeration problem then a cavitation problem. I wonder if the pump has slowly failed because of this suction side leak you mention, over time. I hope the new filter housing works out for you. If it does, you may also want to push to have the pump investigated for damage due to the leaking filter housing.