BX2370 bubbles in HST

[chucky79]

it is down in the filler hole that I see the bubbles, on the surface of the HST fluid. Never saw anything on my dipstick. I run the fluid full on the hash marks as indicated in manual and on the dipstick. I did go this morning to my local dealer and drove one of his new 2670's around the lot for a few minutes then checked down the filler hole. His had bubbles on the surface of the fluid as well. My usually has more bubbles than I saw on his this morning but then again I only drove his around for barely 3to4 minutes on mostly flat ground. I check mine after mowing and trugging up and down my steep pasture hill/driveway. My dealer reassured me that I was paranoid and that it was normal and not to worry. The tractor was still new and breaking in and was under warranty. If a problem occurs it will be covered. I at least feel good about stopping in to speak about my issue so he knows that if something occurs in a few years we had concerns today. They have taken great care of me since before I was even a paying customer so I guess I feel a little better now and im just gonna drive it and work her like he told me. He reassured me that these are TOUGH machines and can take a real licking, probably more than I was going to toss at it.

 

[zoltanthegypsy]

"My dealer reassured me that I was paranoid" I'm no tractor expert, but I'd be inclined to go along with that :laughing:

I thought you were talking about bubbles rising out of the filler or on the dipstick.

Use that little beast and enjoy!

Z.

 

[chucky79]

"My dealer reassured me that I was paranoid" I'm no tractor expert, but I'd be inclined to go along with that :laughing:

I thought you were talking about bubbles rising out of the filler or on the dipstick.

Use that little beast and enjoy!

Z.

No they never came out the top of the neck I can just see them down in there. I was fearful I had air or water In my system to be honest as my knowledge of hydraulic systems is limited. I will admit I have a OCD gene in me and overanalyze most things....

 

[skyhook]

Those bubbles are probably spider egg's, no need to worry.

 

[JOHNTHOMAS]

I've owned 17 Kubotas. One was a gear drive (B2320) one was a used B something I never drove but one time and that was to load it on a trailer to take to Barlows to trade it for a trailer and one was/is an F2680e which I bought new and traded it to Barlows for a new F3080 and a year later bought the F2680e back which I now own with 160 hours on it. During the 11 years I've owned Kubotas I've NEVER gotten a flashlight and looked down the dip stick hole to see what was down there or even tried looking down the hole without a flashlight.
I was assuming, which I'll be even more careful about not doing in the future, that you were talking about "on the dipstick" where you were seeing bubbles. It never entered my mind that you were looking down the dipstick.
Your dealer may want to tell you that it's bad and give you your money back now and save years of grief for you both or at least the under warranty years until your on the pay as you go clock.:laughing:

 

[Code54]

I looked at my BX25 and there is some small air bubble down in there. Was running the hoe on very sloped ground for about an hour when I checked. All works perfect and without issue. I am pretty sure it it just the sloshing around and gears spinning causing the small bubbles. Nothing to worry about in my opinion.

 

[radioman]

I knew what he was talking about - bubbles in the hole of dipstick. I seen it on mine couple times when I wanted to check it after its been running for awhile to see the relationship of it being hot and cold and how hard it worked. I can tell you absolutely that If you drove the BX at 3200 rpms driving it at max travel speed pulling a 16 ft trailer full of wood or mulch for a full hour traveling along, you definitely will see it full of bubbles, no question about it.

 

[chucky79]

my freak out has passed lol....it makes sense that gears, hard work, and high pressure would create a disturbance in the fluid thus producing bubbles. I dont know why i expected anything different.

 

[rbarker]

my freak out has passed lol....it makes sense that gears, hard work, and high pressure would create a disturbance in the fluid thus producing bubbles. I dont know why i expected anything different.

I checked mine after mowing for half an hour and there were plenty of bubbles visible.

Sent from my iPad using TractorByNet

 

[chucky79]

I checked mine after mowing for half an hour and there were plenty of bubbles visible.

Sent from my iPad using TractorByNet

Thanks pal!

 

[RaydaKub]

I was just wondering if the hst, by its very nature, causes bubbles. I haven't ever seen one apart, but from the threads here, they talk about oil pumping and hitting the swash plate at varying angles. That sounds to me like a perfect time for bubbles to be formed. But then I might be misunderstanding the whole setup.:confused2:

 

[MHarryE]

Bubbles in the high pressure loop = bad thing. The hydro requires an oil film between the swash plate and the piston slippers. Bubbles result in cavitation which takes the highly loaded parts to pieces a little bit at a time.

Bubbles in the oil reservoir (in this case transmission housing) after running = perfectly normal although too many can indicate a problem. Your system has an open center pump, or multiple open center pumps. Like my hydro tractor has open center pumps for steering, implements, and charging the hydro. They are constant displacement - the take a full gulp of oil which makes the circuit and ends up back in the reservoir (transmission housing) which is open to atmosphere (vented). That stirs up oil and results in bubbles. The design guideline is to have reservoir capacity large enough so the oil only makes a circuit once every 2 minutes. This gives time for air bubbles to disperse. In general nobody adheres to this guideline except in factory machinery. Reservoir needed gets way out of hand. Mobile equipment companies depend on oil companies to help them out.

Think of the other things that can stir the pot creating bubbles. Is the reservoir the transmission housing with a lot of gears also churning away?

Leaking suction hoses can also introduce air but in general those leaks start big problems quickly. Pumps don't like air on the inlet side - even something like a loose hose clamp or loose fitting can shut you down all together.

Since you don't report any other symptoms, it's likely no problem but since you aren't familiar with the tractor, it is a wise thing to have the dealer give it a look see when he has a chance, just like you plan.

 

[JOHNTHOMAS]

Convinced MHarryE knows what he's talking about. Great response MHarryE.:thumbsup:

 

[BXman98]

Sometime, depending on how long you use the machine for, the HST fluid will bubble because an HST tractor creates a lot of heat. So it will bubble. It's normal to see. But once the fluid cools down the bubbles will go away.