NX6010 suction side hydro leak

[Overtaxed]

GREAT NEWS! glad its all together again. As you also had mentioned, I would def push forward on the hydraulic pumps replacement, or at the very least, opened up and inspected for damage due to compromised oil from foaming. I'm unsure of how this may have effected the axial piston pumps in the HST, or the power steering motor, but I would worry less about those, as its the hydraulic pumps that are taking the brunt of the foamed oil straight from the filter housing.

Thanks for getting back to everyone! Surely this thread will assist others scouring the internet for answers.

Is there something to "see" if there's damage to the pump? I'm a bit concerned about it, but I have no idea how to get Kioti to tear down the pump and actually say "there's damage, replace it" or "nope, it's fine, put her back together". The pump is about 1500 bucks, IIRC (the dealer ordered it for me, assuming it would be that). Also, that sounds like something that would be covered under the powertrain (6 year) warranty, right? I'm only 2 years in with this tractor, so, if this problem will eventually rear up, maybe I just wait until it breaks? Just not looking forward to starting a battle with Kioti over this, but, if there's ammo (like "it's devastating to pumps to cavitate" as another poster mentioned), well then, yeah, I want them to fix the things that this broke too.

Thanks!

 

[JimR]

Is there something to "see" if there's damage to the pump? I'm a bit concerned about it, but I have no idea how to get Kioti to tear down the pump and actually say "there's damage, replace it" or "nope, it's fine, put her back together". The pump is about 1500 bucks, IIRC (the dealer ordered it for me, assuming it would be that). Also, that sounds like something that would be covered under the powertrain (6 year) warranty, right? I'm only 2 years in with this tractor, so, if this problem will eventually rear up, maybe I just wait until it breaks? Just not looking forward to starting a battle with Kioti over this, but, if there's ammo (like "it's devastating to pumps to cavitate" as another poster mentioned), well then, yeah, I want them to fix the things that this broke too.

Thanks!

You can do the research on this issue as there is tons of info out there on cavitation. Here is just one link Damages due to Pump Cavitation - EnggCyclopedia All you need to do is type in cavitation on a hydraulic pump too see what pops up

 

[YLee Kioti]

Porous filter housing. Hmmm you know highly plausible.
Anyone remember back in the day, long ago when NASCAR changed some rules on intake manifolds because of suspected cheating with porous manifolds? Or something like that, its been so long ago.

 

[xcgreene]

Is there something to "see" if there's damage to the pump? I'm a bit concerned about it, but I have no idea how to get Kioti to tear down the pump and actually say "there's damage, replace it" or "nope, it's fine, put her back together". The pump is about 1500 bucks, IIRC (the dealer ordered it for me, assuming it would be that). Also, that sounds like something that would be covered under the powertrain (6 year) warranty, right? I'm only 2 years in with this tractor, so, if this problem will eventually rear up, maybe I just wait until it breaks? Just not looking forward to starting a battle with Kioti over this, but, if there's ammo (like "it's devastating to pumps to cavitate" as another poster mentioned), well then, yeah, I want them to fix the things that this broke too.

Thanks!

Its not cavitation in your particular situation. Cavitation is caused by extreme low pressure typically on the suction side of a pump, impeller, propeller, what have you. Low pressure causes the liquid to boil, then these bubbles quickly collapse again upon reaching the discharge side of the pump where the pressure rises. Where these tiny bubbles collapse back you'll find erosion of the pump metal from the repeated bubble formation and collapsing.

In your situation, the foam bubbles are throughout the oil, harming an oils film strength, degrades the oil quickly through oxidation causing a variety of other problems. Air is not a very good lubricator. Your oil had a lot in it. This is easily proven to be terrible for any type of equipment requiring oil.

If you want the best firepower to help your cause, send an email to your oils manufacturer and ask them why your particular situation may be bad for the pump. They will do their best to explain this for you. Then you will have facts, from the best source, to show the dealer should this become a problem.

 

[dfkrug]

In your situation, the foam bubbles are throughout the oil, harming an oils film strength, degrades the oil quickly through oxidation causing a variety of other problems. Air is not a very good lubricator. Your oil had a lot in it.

Yeah, and subjecting foamy oil to 2500psi will collapse the fluid under pressure very quickly. This can cause dieseling inside the bubbles (bad!), but even if it does not, the fluid will get extra-hot. Fast. Overheated oil then damages the pump thru loss of lubrication and cavitation.

I rebuilt a Kioti (Cassappa) pump a few years back. I posted the post-mortem, showing the damage. I would re-post, but our DSL lines are out for a while. Kioti went to Joyang pumps on my CK. I wonder what they use now on the NX's....

 

[Overtaxed]

Whelp.. Wanted to provide what hopefully is the final update on this issue. Put about 5 hours on the machine yesterday and guess what? Kioti can build a hydrostat as good as Deere. It's a different machine, this has clearly been an issue since day 1 I got the tractor (that's progressively gotten worse). The machine has never been this smooth and responsive (and it's cold out!). I can start it and take off immediately (I don't, but I can), my FEL is smooth about 5 seconds after starting the engine, 3PT is smooth. It's just markedly better all over and much, much more similar (identical, IMHO) to the Deere that started this whole thing for me. If I'd driven a hydrostat for any period of time when I took delivery of this machine I would have immediately had them fix it, it was my inexperience that made me think "well, it's a hydro, I guess that's how they work". Dealer should have caught this during assembly/delivery, but, in their defense, it did get progressively worse. Still should have caught it, especially at the 50 hr service, IMHO. The big takeaway, if your hydro isn't fast and smooth, something is wrong! I can hear the old timers saying "duh", but, hey, hopefully it will help someone else without a ton of experience on a machine like this. I've been on tractors for 30 years, but if you've not used a hydro before, you may not realize that something is wrong.

Anyway, thank you everyone for the help! I'm still not sure what I'm going to do about the possible damage to the pump. I still have 4 years left on the Kioti 6 year warranty, so, I might just let it ride and see what happens. What I'd really like to do is get Kioti to agree that the warranty on the pump will be extended indefinitely should any issues arise that are attributed to this problem. Good luck, right? I'm just happy my tractor is running right/better than ever again, and want to get back to work, it's been months trying to get this sorted and I'm way behind. Gotta take out my new Bison blade and grade off some trails, had that thing for almost a month and it's not even dirty yet!

 

[Threepoint]

[snip] The big takeaway, if your hydro isn't fast and smooth, something is wrong! I can hear the old timers saying "duh", but, hey, hopefully it will help someone else without a ton of experience on a machine like this.[snip]

Nah, the real old timers would say: "Duh! It's one of those newfangled "hydrostat" tractors. I've always known they're gonna' be nothing but trouble!" :laughing:

Thanks very much for the great update!

 

[woolyAcres]

@Overtaxed-
Glad to hear this got sorted out and that you are once again a happy Kioti owner. If Kioti has known about this, such as a bad run of filters, isn't a recall in order? Do such things exist for tractors?

 

[Overtaxed]

Oh no... Spoke to soon. Put another 50-60 hours on the tractor and, guess what? It's back. Now that I have the clear line on the suction side I can easily see the bubbles and, while the noise if VERY slight compared to what it used to be (nobody would ever notice if you hadn't heard it before) it's there. And the loader is the slightest bit jumpy again. I'm at a loss.. What the heck is going on? It's hot here today, this is probably the first day I've used it since it was fixed in this kind of heat. But the symptoms are exactly the same, just much less severe than they used to be. And, interestingly enough, this used to be a lot worse in COLD weather, not hot.

I contacted the dealer, I'm 100% sure he's not going to be happy about it. What the heck do we go after now? We know the filter fixed it before, could I really have ANOTHER bad filter assembly? I have a really hard time believing that, but.. Any ideas?!

 

[xcgreene]

Oh no... Spoke to soon. Put another 50-60 hours on the tractor and, guess what? It's back. Now that I have the clear line on the suction side I can easily see the bubbles and, while the noise if VERY slight compared to what it used to be (nobody would ever notice if you hadn't heard it before) it's there. And the loader is the slightest bit jumpy again. I'm at a loss.. What the heck is going on? It's hot here today, this is probably the first day I've used it since it was fixed in this kind of heat. But the symptoms are exactly the same, just much less severe than they used to be. And, interestingly enough, this used to be a lot worse in COLD weather, not hot.

I contacted the dealer, I'm 100% sure he's not going to be happy about it. What the heck do we go after now? We know the filter fixed it before, could I really have ANOTHER bad filter assembly? I have a really hard time believing that, but.. Any ideas?!

loose connections, poor o-rings/bonded seals when new housing was installed? I'm sorry this is flaring up again.