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?
Hydraulics issue NX5010
- Thread starter Sprouse77
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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?
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.
.....just got started on a project and wanted to finish it first.justman777
Platinum Member
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
Platinum Member
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
Elite Member
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
Elite Member
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 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
Platinum Member
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.
