NX4510 Noisy HST---Normal?

[MichiganIron]

Got home and started right in working on changing out the filter housing. You were right... The banjo fittings were tough to get off and back on. Everything else was a piece of cake. Wound up re-using the same oil (drained into a brand new clean 15 gallon container), and used (stole?) my wife's Whataburger cup as a dipper to transfer the oil from the container back to the tractor.

Bottom line, changing out the filter housing does NOT appear to have worked. When I started it up, I cycled the loader a few times, moved backwards and forwards a little bit, and didn't feel any hesitation or hear any noise. Thought I was good! Decided I would go out and cut some grass, and when I throttled back from PTO speed after cutting for an hour, I heard my noise start up again. I left the engine running and opened the reservoir cap and found it full of bubbles.

I've tightened up every suction side bolt I could find. Short of some special DIY testing technique, the only thing I know to do is take it to the dealer and let them have it for a few weeks of troubleshooting. I'd really hate to do that...

Call me disappointed. :-(

Hoping you checked the air breather on the transmission. We have solved these issues several times just by cleaning out the air breather. If it is plugged or not breathing properly, it caused cavitation of the hydraulic fluid.....the result is jumpy hydraulics.

 

[YLee Kioti]

Got to thinking early this morning about other possibilities, and recalled the tech who last worked on the tractor had given the hydro filter a good twist with a wrench when he put it on. I put mine on hand tight, just like I would a car oil filter. Should I give it a turn with a wrench as well, or were they meant to be put on hand-tight?

On my CK4010HST followed manual instructions and went hand tight.....about 25 hours or so later noticed hyd. fluid on floor of shop. Discovered it was from filter housing on the hyd. filter. Right hand side if sitting in cab. Took filter wrench and went about 1/2 turn no more leaks.
So now each filter service they get a full 1/2 turn with wrench, last thing I want to worry about when cutting is filter falling off.
However, not sure if this could be a source of air intrusion on the suction side of filter gasket and contribute to the noise and bubbles.

No doubt air is sneaking in some how......all the best.....

 

[justman777]

Hoping you checked the air breather on the transmission. We have solved these issues several times just by cleaning out the air breather. If it is plugged or not breathing properly, it caused cavitation of the hydraulic fluid.....the result is jumpy hydraulics.

I did take a look at the air breather a few days ago. The tube appears to be in good shape, and squished it together to make sure there weren't any critters in it, and then blew through it to make sure it was clear. I suppose there could be something further down in the metal part that reaches into the hydro sump. I'll try getting a longer piece of tubing and see if I can blow some air through the metal part to make sure it's clear.

 

[justman777]

Ok....took another look at the air breather tube and verified the tube is clear. I used a longer piece of tubing to breath through the tube and was able to verify it was clear. Just for grins, I left the breathing tube and fill cap off and started the tractor. Got bubbles in the sump almost immediately. I also took a length of pipe and pressed it against the suction side tubing and listened on the other end. Didn't hear anything like the "marbles going through pipes" sound that I would expect from cavitation. At this point, I think I'll replace the seal where the tubing meets the pump, and possibly the seal where the tubing comes from the sump. The only thing i know to do after that is replace the pump.

 

[Overtaxed]

Bottom line, changing out the filter housing does NOT appear to have worked. When I started it up, I cycled the loader a few times, moved backwards and forwards a little bit, and didn't feel any hesitation or hear any noise. Thought I was good! Decided I would go out and cut some grass, and when I throttled back from PTO speed after cutting for an hour, I heard my noise start up again. I left the engine running and opened the reservoir cap and found it full of bubbles.

Sorry man. But I'm curious, it sounds like it did work, but only for an hour? Or did you have some periods of time when it worked OK before you made the change? If the housing fixed it "for a few hours" but then it failed again, sadly, I'd keep looking there (the housing). There just aren't that many places on the suction side for a leak to develop. Mine went from unusable to perfect after the change. So it's obvious that was the problem, even if it failed again, I'd look there first because it's a known issue.

 

[justman777]

Sorry man. But I'm curious, it sounds like it did work, but only for an hour? Or did you have some periods of time when it worked OK before you made the change? If the housing fixed it "for a few hours" but then it failed again, sadly, I'd keep looking there (the housing). There just aren't that many places on the suction side for a leak to develop. Mine went from unusable to perfect after the change. So it's obvious that was the problem, even if it failed again, I'd look there first because it's a known issue.

Well, I'm not sure it worked for an hour, but it didn't seem to make the same noise after I initially started it up after changing the filter housing. It could have been going at it the entire time I was cutting grass, just hard to hear over the engine noise, AC, and radio. To be clear, the noise I have is exactly similar to the noise you were having, but isn't nearly as bad (loud) as yours was...not by a long shot. My loader or three point also aren't jumpy like yours was. I'd describe it as a slight, intermittent hesitation when lifting.

At this point, I think I'm going to try changing out the seal where the tubing meets the pump and see what that does. I'll be looking at the pump after that. Short of that, I may just live with it for a while. The tractor is still usable, and I get no discernable hesitation at higher RPMs.

By chance, do you know what fluid your dealer used when he changed out your filter head?

 

[Overtaxed]

424. And I found that fluid (it's what I was using after the first change) was much better than whatever was in there before.

Please keep us up to date, I'll be curious to know what your final resolution is/was. And my problem was progressive, what you saw in that video was after 2 years of getting worse. When I first got the tractor, it wasn't noticeable to me (but should have been, had I driven a hydro before). But it just got worse and worse through time.

 

[Sprouse77]

Overtaxed.....was this the housing for the filter on the gas tank side (HST filter) or the pump side (hydraulic filter)?

 

[justman777]

Overtaxed.....was this the housing for the filter on the gas tank side (HST filter) or the pump side (hydraulic filter)?

Overtaxed and I have communicated back and forth on this. The filter housing he's talking about is on the pump side. His dealer changed his out and it seemingly resolved his issue. Unfortunately, it didn't do anything for me. Note the only places you have the potential for aeration to occur is on the suction side where the tubing runs from the sump to the pump, or in the fluid reservoir from the fluid spraying back into the reservoir from an elevated position. Everything I've read indicates the fluid return should be below the level of the fluid to avoid aeration. I think I've learned more about hydraulics from this problem than I ever thought I would.

 

[Sprouse77]

Overtaxed and I have communicated back and forth on this. The filter housing he's talking about is on the pump side. His dealer changed his out and it seemingly resolved his issue. Unfortunately, it didn't do anything for me. Note the only places you have the potential for aeration to occur is on the suction side where the tubing runs from the sump to the pump, or in the fluid reservoir from the fluid spraying back into the reservoir from an elevated position. Everything I've read indicates the fluid return should be below the level of the fluid to avoid aeration. I think I've learned more about hydraulics from this problem than I ever thought I would.

As you can probably see....I'm trying my best to keep my tractor by solving my problem...I replaced the big filter on the pump side and didn't catch the HST filter until tonight while looking for any cracks, leaks or wet places. I'm hoping the filters help some since I've neglected that at the 50 hour mark. It's really annoying when you think you're limited to so much time on steep ground and then you have to let everything cool and settle.