B2100 HST Water Contamination

[Bolts-N-Hose]

My B2100 is used primarily to run a front mount snowblower. It uses the 3pt circuit to lift it. This means the cylinder has a hose on top, but just an open breather on the bottom port. I noticed that the cylinder must leak internally, because after leaving it for a while, hydraulic fluid squirts out of the breather when I lift it.

I noticed the other day that the hydraulic fluid of the machine is contaminated with water. I'll do a few flushes to remedy that, but I need to know where it came in. My theory is that it came in through that leaky cylinder. Every time the blower goes down, the breather sucks in air. It could be sucking in snow and filling the cylinder with water. When the blower goes up, that water can be forced past the internal leaking seals and into the fluid. Is this conceivable? How else would water get in the HST system? It is primarily stored indoors, but I do think it was outside for a little bit this fall. I feel like the machine should be able to stay out in the rain unless there is a problem.

Thoughts? Photo is of the cylinder. You can see the breather is covered in snow.

 

[GreensvilleJay]

I'd replace the double acting cylinder with a single acting cylinder..problem solved,forever.
other option, is to plumb the 'breather' port into a 'tank return'
maybe option, turn cylinder over, point breather down,cover breather to prevent snow/rain from entering

 

[Bolts-N-Hose]

I'd replace the double acting cylinder with a single acting cylinder..problem solved,forever.
other option, is to plumb the 'breather' port into a 'tank return'
maybe option, turn cylinder over, point breather down,cover breather to prevent snow/rain from entering

So you do think that's the possible point of entry?

What difference would a single acting cylinder make? Won't it also have a vent for the non fluid side that could potentially do the same thing? I have no idea, but I'd think it would still need to vent that side of the cylinder.

I happen to have a spare cylinder. It has a 4' hose on both ports so I was thinking I'd run it up to the machine somewhere with a vent screen so it has less potential to ingest water. Main concern is figuring out if this is the way water got in.

 

[GreensvilleJay]

look at it this way ...
EVERY time you extend that cylinder, it sucks wet air in through the breather port,and some of that moisture gets pushed around the leaky seal into the oil. Doesn't matter WHERE the 'breather' is, it'll suck in 'wet' air.
A 'single acting' cylinder doesn't need second port,so no need for breather vent either. Millions of JEEP/truck mounted snowplows use single acting cylinders for decades....
EVERY 'vent' on your tractor is a possible source,so check them all but for SURE that one IS bad news.

 

[Bolts-N-Hose]

look at it this way ...
EVERY time you extend that cylinder, it sucks wet air in through the breather port,and some of that moisture gets pushed around the leaky seal into the oil. Doesn't matter WHERE the 'breather' is, it'll suck in 'wet' air.
A 'single acting' cylinder doesn't need second port,so no need for breather vent either. Millions of JEEP/truck mounted snowplows use single acting cylinders for decades....
EVERY 'vent' on your tractor is a possible source,so check them all but for SURE that one IS bad news.

So I guess that answers what I didn' t know. You say a single acting cylinder doesn't have to equalize the back end? If true, for sure that's a better solution than relocating the vent. Relocating the vent will be better than nothing, but not as good as one that doesn't need a vent. Honestly, I'd prefer to add a circuit to the machine and use a double acting cylinder, but that's not a project for mid winter without a heated shop.

 

[kubotasam]

So I guess that answers what I didn' t know. You say a single acting cylinder doesn't have to equalize the back end? If true, for sure that's a better solution than relocating the vent. Relocating the vent will be better than nothing, but not as good as one that doesn't need a vent. Honestly, I'd prefer to add a circuit to the machine and use a double acting cylinder, but that's not a project for mid winter without a heated shop.

A single acting cylinder will not work on this application. If you look closely at the picture of the cylinder you can see that it raises the snow blower by retracting the cylinder. A single acting cylinder extends.

 

[whitetiger]

You can not get water into the hydraulic system through the cylinder vent.
For that to happen, the atmospheric pressure would have to be greater than the hydraulic pressure in the cylinder.

 

[Bolts-N-Hose]

You can not get water into the hydraulic system through the cylinder vent.
For that to happen, the atmospheric pressure would have to be greater than the hydraulic pressure in the cylinder.

Under normal circumstances, I wouldn't even think of it. The only reason I propose it as possible is because the cylinder leaks internally. It seems like when the blower is sitting in the down position, it could be filled partially with water from use. Then as it sits there, oil leaks into the cylinder. When I go to use it next, a fair amount of oily water is shooting out violently from that vent. To me that means that the bottom of the cylinder is contacting fluid and pressurizing it. (the hole in the vent is fairly small) Most of it probably goes out that vent, but I seems feasible that some of it might force it's way past that leaking internal seal. Its the only thing I can think of. What are some other ways that water could make it's way in?

If that is the case, the best remedy I can think of is to flip the cylinder so the vent is on the underside. Any accumulation in the cylinder will naturally drain out and not be allowed to collect past the point where the cylinder will contact it. This is of course with a new cylinder, since this one leaks.

 

[Bolts-N-Hose]

A single acting cylinder will not work on this application. If you look closely at the picture of the cylinder you can see that it raises the snow blower by retracting the cylinder. A single acting cylinder extends.

That's a good point. I probably would have run against that when trying to find one. Side note, Is it correct that a single acting cylinder doesn't need to equalize the non pressure side? It seems like it would have to do something with the air, but I don't have any experience there.

 

[kubotasam]

That's a good point. I probably would have run against that when trying to find one. Side note, Is it correct that a single acting cylinder doesn't need to equalize the non pressure side? It seems like it would have to do something with the air, but I don't have any experience there.

That's a good point. I probably would have run against that when trying to find one. Side note, Is it correct that a single acting cylinder doesn't need to equalize the non pressure side? It seems like it would have to do something with the air, but I don't have any experience there.

A single acting cylinder does not have a non pressure side. The OD of the rod is the same as the ID of the cylinder. Fluid under pressure goes in at the base of the cylinder and pushes the rod out.

 

[North Idaho Wolfman]

No you can not get water in the hydraulic system via that vent port, it simply just can't happen.
How do you know you have water in the system?
Did you drain it and see the water?

 

[Bolts-N-Hose]

No you can not get water in the hydraulic system via that vent port, it simply just can't happen.
How do you know you have water in the system?
Did you drain it and see the water?

How can you say it cant happen? You don't think pressurized water could be forced past the leaking seals in the cylinder? I know that the oil side should be under pressure when lifting, and should be leaking oil OUT instead of contaminated fluid back in, but I can't think of any other way. How else would it happen? The machine rarely goes outside, but may have been out for a rain storm. I feel like a tractor should have no problem sitting out in the rain.

The fluid is like chocolate milk, so obviously water contaminated.

The cylinder has been leaking for a while, and I just ignored it. Every time I lift it up after sitting for a few days, a stream of fluid hits the shop wall. Hard. I noticed a bit ago that the fluid was milky so I checked the dipstick and opened the fill port on the machine, but the fluid was clear. Fast forward to 2 weeks ago and the stream hitting the wall was MUCH larger than previous, and much milkier. Checked the dipstick and the fill port and it's milky. Bought enough UDT2 for 3 drain/fills.

What are other ways water can get in!!??

 

[North Idaho Wolfman]

How can you say it cant happen? You don't think pressurized water could be forced past the leaking seals in the cylinder? I know that the oil side should be under pressure when lifting, and should be leaking oil OUT instead of contaminated fluid back in, but I can't think of any other way. How else would it happen? The machine rarely goes outside, but may have been out for a rain storm. I feel like a tractor should have no problem sitting out in the rain.

The fluid is like chocolate milk, so obviously water contaminated.

The cylinder has been leaking for a while, and I just ignored it. Every time I lift it up after sitting for a few days, a stream of fluid hits the shop wall. Hard. I noticed a bit ago that the fluid was milky so I checked the dipstick and opened the fill port on the machine, but the fluid was clear. Fast forward to 2 weeks ago and the stream hitting the wall was MUCH larger than previous, and much milkier. Checked the dipstick and the fill port and it's milky. Bought enough UDT2 for 3 drain/fills.

What are other ways water can get in!!??

NO I don't think an OPEN vent port on a cylinder could hold enough back pressure to bypass a seal that's meant to hold thousands of pounds of pressure.
If the water got in that port, it will just be forced out that port!
If your so worried that, that is the cause of all your wow's put a line off of it to a dry location or put a vent filter on it.

Your most likely candidates for water getting into the system are plain old condensation, a leaking boot, a bad dip stick seal, or case vent on top of the transmission that has failed.

One other very common issue is someone does a fluid and filter change and they don't drain all the fluid's out of the 5 or 6 drain locations.
They pick one or two locations and call it good, meanwhile all the other locations are holding water and it just adds up.

 

[Bolts-N-Hose]

NO I don't think an OPEN vent port on a cylinder could hold enough back pressure to bypass a seal that's meant to hold thousands of pounds of pressure.
If the water got in that port, it will just be forced out that port!
If your so worried that, that is the cause of all your wow's put a line off of it to a dry location or put a vent filter on it.

Your most likely candidates for water getting into the system are plain old condensation, a leaking boot, a bad dip stick seal, or case vent on top of the transmission that has failed.

One other very common issue is someone does a fluid and filter change and they don't drain all the fluid's out of the 5 or 6 drain locations.
They pick one or two locations and call it good, meanwhile all the other locations are holding water and it just adds up.


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I appreciate the feedback. For sure the water will take the path of least resistance. I just thought that maaayyyybe since the vent has a small orifice that the fluid is being forced through, that short spike of pressure might overpower the seals. But yeah. Even then it has to overcome the full hydraulic pressure and even if it did overpower it, how much water could really be forced in? IDK. I'm just looking for anything, really.

I'll check my vents etc. Its just baffling to me since as I said, its stored mostly indoors and I feel like this is more water than condensation could allow for.

My manual shows 3 locations for draining this B2100. Are you saying there could be more? I've had the plugs out for 2 days now, just do drain as much as possible.

 

[North Idaho Wolfman]

I forgot a vent, this is very common one to cause issues because it's fairly hidden.

 

[North Idaho Wolfman]

4 drain locations
First picture there is 2 drains pointed to.
The drain in blue will only be trace water, if any, out of the clutch housing.
If there is fluid you have an issue.
The back drain in yellow is Hydraulic fluid.
Pull and clean the filter screen, replace if rusty or does not clean well.
And replace the spin on filters.

If I'm dealing with a water contaminated system.
I typically do the fluids and filters twice in a short time frame.

 

[Bolts-N-Hose]

I just re-read the manual and it does mention the 4 drains. I'll get that last one up front. Inspection reveals that there is no O ring on the filler plug. I feel like that exposed, flat location could let a fair amount of water in. I'll check that one by the clutch housing too, but this seems like a viable culprit. The plug is ribbed, and a fairly tight fit, but the o ring is there for a reason. I'm sure I have one in my O ring kit. This tractor had a cab on it that I bet kept that plug fairly protected. Now without that cab I can see how it would let rainwater in. Agree?

 

[North Idaho Wolfman]

I just re-read the manual and it does mention the 4 drains. I'll get that last one up front. Inspection reveals that there is no O ring on the filler plug. I feel like that exposed, flat location could let a fair amount of water in. I'll check that one by the clutch housing too, but this seems like a viable culprit. The plug is ribbed, and a fairly tight fit, but the o ring is there for a reason. I'm sure I have one in my O ring kit. This tractor had a cab on it that I bet kept that plug fairly protected. Now without that cab I can see how it would let rainwater in. Agree?

Yep no O-ring on the filler plug would 1000% cause issues with water getting in, even with a cab!

 

[Bolts-N-Hose]

Yep no O-ring on the filler plug would 1000% cause issues with water getting in, even with a cab!

Craziness. Honestly I'd question that design, but overall kubota makes a great machine so I'll let it go. lol. I guess it's a good thing that I keep it inside, but I think I remember at least one rainstorm this late fall that it sat out. I appreciate the help. I've got 2 filters and 10 gallons of UDT to run through thing now. Gotta get to work.