Hydraulics issue NX5010

[Sprouse77]

Guys...very sorry if I've reposted an issue already noted.....I've looked and not finding my specific issue/issues. I have an NX5010 HST cab tractor. About a month ago, I was mowing some steep ground when my forward pedal just didn't work. Reverse would work but not forward and I lost my power steering. I checked the fluid, it was low. Filled it to the mark......mowed with it yesterday while it was hot out, on steep ground again, and lost power steering and partially forward motion again. The tractor wouldn't maintain a smooth speed in low range as it wanted to jerk between very slow and fast speed suddenly. I go to check the fluid and when I pull the dipstick out, fluid spewed out like a water fountain......it settled and is still within specs of full but power steering is still not working at low idle.....any ideas? The Kioti service guy is stumped. Let me add that I know the vent isn't blocked and the power steering does work better after idling up some.

 

[TN8Man]

I'm experiencing a similar problem although it's limited to the reverse motion and no issues with steering. I even experience the problem on hot days when using the tractor to mow on hilly terrain. My local shop thinks its related to the hydraulic solenoid coils that control forward/reverse travel. My problem is the failure mode is intermittent and goes away after the tractor cools. The shop can't get it to fail so they don't know which part needs to be replaced yet. Apparently this is a known issue but the shop is reluctant to admit it.

 

[JimR]

Guys...very sorry if I've reposted an issue already noted.....I've looked and not finding my specific issue/issues. I have an NX5010 HST cab tractor. About a month ago, I was mowing some steep ground when my forward pedal just didn't work. Reverse would work but not forward and I lost my power steering. I checked the fluid, it was low. Filled it to the mark......mowed with it yesterday while it was hot out, on steep ground again, and lost power steering and partially forward motion again. The tractor wouldn't maintain a smooth speed in low range as it wanted to jerk between very slow and fast speed suddenly. I go to check the fluid and when I pull the dipstick out, fluid spewed out like a water fountain......it settled and is still within specs of full but power steering is still not working at low idle.....any ideas? The Kioti service guy is stumped. Let me add that I know the vent isn't blocked and the power steering does work better after idling up some.

Is your fluid full of small air bubbles? Your power steering may be air bound. Crank it up and keep going back and forth lock to lock to get the air out of it.

 

[JimR]

I'm experiencing a similar problem although it's limited to the reverse motion and no issues with steering. I even experience the problem on hot days when using the tractor to mow on hilly terrain. My local shop thinks its related to the hydraulic solenoid coils that control forward/reverse travel. My problem is the failure mode is intermittent and goes away after the tractor cools. The shop can't get it to fail so they don't know which part needs to be replaced yet. Apparently this is a known issue but the shop is reluctant to admit it.

This issue should be happening to all the NX series tractors with HST. I haven't had these issues with mine yet.

 

[TN8Man]

This issue should be happening to all the NX series tractors with HST. I haven't had these issues with mine yet.

So far I only experience the failure mode intermittently on hot days and after several hours of PTO operation on somewhat steep hilly terrain.

 

[JimR]

So far I only experience the failure mode intermittently on hot days and after several hours of PTO operation on somewhat steep hilly terrain.

Is your tractor facing uphill when this happens? If so, maybe it is too steep and the hydraulic pump is sucking air.

 

[TN8Man]

Is your tractor facing uphill when this happens? If so, maybe it is too steep and the hydraulic pump is sucking air.

The last time I experienced the failure mode (a few days ago) it occurred it was while I was traveling somewhat horizontal on the hill. If the failure mode was due to steep grade I would probably experience the problem more often and no matter how long I use it.

 

[Sprouse77]

I'm experiencing a similar problem although it's limited to the reverse motion and no issues with steering. I even experience the problem on hot days when using the tractor to mow on hilly terrain. My local shop thinks its related to the hydraulic solenoid coils that control forward/reverse travel. My problem is the failure mode is intermittent and goes away after the tractor cools. The shop can't get it to fail so they don't know which part needs to be replaced yet. Apparently this is a known issue but the shop is reluctant to admit it.

Same here....after my tractor cooled overnight, it's all good again. I do have a fair amount of steep ground and it's been hot when I mow. I know if I take it in, they won't find the same issue unless they came out here and used it for a couple hours. I'm thinking about trading for a Synchro Shift model.....is that a bad idea? I'm not worried about steep ground and shifting....just don't want the HST issue anymore.

 

[Sprouse77]

Is your fluid full of small air bubbles? Your power steering may be air bound. Crank it up and keep going back and forth lock to lock to get the air out of it.

I've done that and it doesn't work itself out until it cools is the problem.

 

[TN8Man]

Same here....after my tractor cooled overnight, it's all good again. I do have a fair amount of steep ground and it's been hot when I mow. I know if I take it in, they won't find the same issue unless they came out here and used it for a couple hours. I'm thinking about trading for a Synchro Shift model.....is that a bad idea? I'm not worried about steep ground and shifting....just don't want the HST issue anymore.

I had the ck35 hst previously and never had this issue so I don't think it's HST vs manual transmission. I think it's fixable. My shop said if I had any more issues with it they will replace the unit that contains the solenoid coils.

 

[Sprouse77]

Is your fluid full of small air bubbles? Your power steering may be air bound. Crank it up and keep going back and forth lock to lock to get the air out of it.

It does seem to have small air bubbles and when I pull the dipstick, that fluid is a little frothy at first and just continues to spew out until it cools down. When I take the red fill cap off, I can hear air sucking/blowing....I'm guessing that should be normal?

 

[Sprouse77]

Ok....got the new filter today and fluid. I noticed the plug had a decent amount of filings on the magnet. The magnets on the filter housing were pretty dirty too. So far, steering is more responsive and loader works smoother.....maybe this won't fix it, but it'll have to help. This was the first filter with 78 hours on the machine....don't yell at me .....just got started on a project and wanted to finish it first.

 

[justman777]

You might want to have your dealer check for suction side air leaks. That'll make the fluid frothy and expand it to the point where it'll go wherever it can and cause the issues you're having. Recall that air compresses whereas fluid doesn't. If your fluid is full of air, it'll cause issues with just about everything that uses it---steering, three point, etc. Just FYI, I have an HST with a suction side air leak that I believe is in the pump. We've replaced every o-ring on the suction side, the suction side filter, and filter housing. Air is still getting in somewhere, and I suspect it's because of the seals around the pump. My dealer is stumped because no fluid is leaking out. But....suction side air leaks sometimes don't leak under pressure. The seal back up when they're not under negative pressure.

 

[Sprouse77]

You might want to have your dealer check for suction side air leaks. That'll make the fluid frothy and expand it to the point where it'll go wherever it can and cause the issues you're having. Recall that air compresses whereas fluid doesn't. If your fluid is full of air, it'll cause issues with just about everything that uses it---steering, three point, etc. Just FYI, I have an HST with a suction side air leak that I believe is in the pump. We've replaced every o-ring on the suction side, the suction side filter, and filter housing. Air is still getting in somewhere, and I suspect it's because of the seals around the pump. My dealer is stumped because no fluid is leaking out. But....suction side air leaks sometimes don't leak under pressure. The seal back up when they're not under negative pressure.

That all makes perfect sense.....now if I could only find where that issue would be.....if that's the issue. I think I read where some were have the issue close to the filter where the short rubber hose connects the 2 metal lines coming from the pump side......I might check those clamps next time I have it out.

 

[justman777]

That all makes perfect sense.....now if I could only find where that issue would be.....if that's the issue. I think I read where some were have the issue close to the filter where the short rubber hose connects the 2 metal lines coming from the pump side......I might check those clamps next time I have it out.

Have to correct myself a little here---suction side air leaks sometimes don't leak fluid under suction. If it's sucking in, it's not going to leak because....well....it's sucking air in. Every point in the hydraulics system after the pump is a potential leak point as everywhere else is under pressure.

I replaced the tubing you're talking about with clear tubing and quality clamps. It served two purposes for me. The first was to ensure I had a good seal and that the tubing wasn't the air leak point. The second was so I could see what the fluid looked like. The video here gives my results. Kioti NX451 Filter Reinstall - YouTube

Note that I used some good quality stainless steel clamps. I still have the clear tubing in place today, and can tell once the fluid gets aerated. My HST also makes sounds like a pump that has air in the lines. You can barely hear it over the noise of the engine, but it's there----like an intermittent "whump whump" noise that varies in frequency (occurrence), just like you'd expect from pumping air.

 

[JimR]

Have to correct myself a little here---suction side air leaks sometimes don't leak fluid under suction. If it's sucking in, it's not going to leak because....well....it's sucking air in. Every point in the hydraulics system after the pump is a potential leak point as everywhere else is under pressure.

I replaced the tubing you're talking about with clear tubing and quality clamps. It served two purposes for me. The first was to ensure I had a good seal and that the tubing wasn't the air leak point. The second was so I could see what the fluid looked like. The video here gives my results. Kioti NX451 Filter Reinstall - YouTube

Note that I used some good quality stainless steel clamps. I still have the clear tubing in place today, and can tell once the fluid gets aerated. My HST also makes sounds like a pump that has air in the lines. You can barely hear it over the noise of the engine, but it's there----like an intermittent "whump whump" noise that varies in frequency (occurrence), just like you'd expect from pumping air.

Great video and very nice clamps you used there. I see what you mean about the sir bubbles. I replaced my hose with clear hose also. I do not have that air bubble issue on my MX4510. I too think it is your pump where the air is getting in. I recall your original post about this.

 

[DieselBound]

Interesting...

I recently noted that when I first pull out the hyd dip stick that the fluid kind of dumps out and it clear to the top of the casing/tube. But then I wipe off the dip stick and reinsert and pull back out and then I get a normal reading: the fluid drops back down below the top of the case/tube. Going to watch to see if this is a regular thing with my tractor. Just don't recall seeing it before; but I suppose, it's possible that it's just something that's been the case and I never really thought too much of it.

I've got 525+hrs on my NX: fluid and filter changes done on schedule (by me); filter changes coming up at 600hrs. Really no hint of hydraulic issues.

 

[justman777]

Interesting...

I recently noted that when I first pull out the hyd dip stick that the fluid kind of dumps out and it clear to the top of the casing/tube. But then I wipe off the dip stick and reinsert and pull back out and then I get a normal reading: the fluid drops back down below the top of the case/tube. Going to watch to see if this is a regular thing with my tractor. Just don't recall seeing it before; but I suppose, it's possible that it's just something that's been the case and I never really thought too much of it.

I've got 525+hrs on my NX: fluid and filter changes done on schedule (by me); filter changes coming up at 600hrs. Really no hint of hydraulic issues.

I think the dip stick thing is just how it's designed. It sits below the level of the fluid, so any air that gets trapped in there has nowhere to go. You pull the stick out, and whatever is in the way of the air getting out is going to shoot out. Once you put the stick back in, the fluid has leveled off with the other fluid in the sump and you can take your reading.

 

[dusty3030]

Have to correct myself a little here---suction side air leaks sometimes don't leak fluid under suction. If it's sucking in, it's not going to leak because....well....it's sucking air in. Every point in the hydraulics system after the pump is a potential leak point as everywhere else is under pressure.

I replaced the tubing you're talking about with clear tubing and quality clamps. It served two purposes for me. The first was to ensure I had a good seal and that the tubing wasn't the air leak point. The second was so I could see what the fluid looked like. The video here gives my results. Kioti NX451 Filter Reinstall - YouTube

Note that I used some good quality stainless steel clamps. I still have the clear tubing in place today, and can tell once the fluid gets aerated. My HST also makes sounds like a pump that has air in the lines. You can barely hear it over the noise of the engine, but it's there----like an intermittent "whump whump" noise that varies in frequency (occurrence), just like you'd expect from pumping air.

Do you have a link to or could you let me know what tubing you used? Thanks!

 

[NC419N]

Been there done that gone Shuttle
Good luck