Kubota L3400 --Water in Hydraulics

[Downeast Jim]

Greetings! New member to this forum from Maine with a recurring Kubota problem. I have been wrestling with water in my trans/hydraulic lines for the last two winters. I own a 2007 L3400 manual transmission-- always kept outdoors. Two winters ago, my hydraulics (steering, bucket) began to get really stiff in sub-freezing weather. Last winter was brutally cold; I had a total freeze up when temps fell below 20F (which was about everyday for 2 months); the bucket, steering would not respond until I used a propane heater aimed at the filter for 15-20 minutes. The dealer told me the only way to fix the problem was to drain and re-fill the reservoir (nearly 8 gallons) as many times as it took to purge the water. At $24/gallon for Kubota SUDT, that's a painfully expensive fix. I drained and refilled it once, hoping once would be enough. But the freeze-ups continued.

Heading into another winter here. I've read many a forum entry and the consensus is that, yes, the only way to really rid water from the system to use oil--lots of it. My question is, can I use cheap oil for the first two or three fill-ups, and then, when I am confident that I have reclaimed all the water from the system, use the Kubota oil for the final fill. If so, what is the cheapest, most compatible oil I can use. Tractor Supply sells 5 gallon buckets of Traveller for $35. If I'm going to drain it and throw it, I'd like to throw away the cheapest oil possible. Would that work?

Another question: do they sell a multi-stage filter for the Kubota that would separate water out? It might be cheaper the blow 3 or 4 filters than 25 gallons of oil.

The real issue is: how is water getting into my system? I think accumulated condensation is a possibility. But the rubber boot to my shift stick is tattered. Could rainwater be getting here at the shift? Otherwise, ideas?

Thanks.

 

[k0ua]

The real issue is: how is water getting into my system? I think accumulated condensation is a possibility. But the rubber boot to my shift stick is tattered. Could rainwater be getting here at the shift? Otherwise, ideas?

Rain water has been getting into tractor transmissions thru the shift stick boot for decades..

 

[teg]

...I think accumulated condensation is a possibility...

There's no problem using cheaper oil, especially since you don't plan to keep it in there.

How many times do to you run the tractor hard (higher temps)? Could you cover the tractor with a tarp?

 

[100 td]

Don't forget to pull the plugs on the brakes/axle housings, oil floats on water so it will get trapped at all the low points in nooks and crannies.

 

[rswyan]

One thing I'd sure check is the trans/rear axle case vent, if your tractor has one (pretty likely I'd think)

On our B2910 it is a piece of molded rubber tube, shaped like a shepherd's crook, and located on the right side of the case, underneath the seat.

I'd check it for two reasons:

1. When I went to do a very through cleaning/degreasing of our 2910 (which included removing the seat), I found that part of the rubber tube had rotted away, which would allow water a direct path via gravity into machine if the seat was up (how many folks who leave their tractors outside, fold up the seat to prevent rain from puddling on it ? ... I know I do on mine)

2. To ensure that didn't happen when I was hosing it off, I capped the metal nipple the rubber tube fits onto with an automotive vacuum cap. Just slip fit ... no clamp.

Took me a little longer than I intended to get the correct replacement vent tube and install it.

The end result of that was that enough moisture had condensed in the sump, that when I was operating it on a cold winter day, the pressure generated actually pushed the left rear axle seal out of the housing, allowing the hydraulic fluid to leak out ... and the vacuum cap stayed on !

Fortunately I was close to the house and noticed it before it all drained out and was able to make it to just in front of the garage door before losing all motive power. The wife and I pushed it into the garage (no easy feat)

I managed to catch a good bit of fluid that was still draining, which was pretty "milky", indicating a fairly significant amount of water.

Point being: if the moisture has no route to escape when heated to the point of boiling off, you likely will be harboring significant amounts of it in the sump.

 

[LD1]

Yep, make sure you pull the drain bolts at the brake/axle housing like mentioned above. I always forget those when draining, until I realize that I have only drained ~5 gallons out and KNOW that I was full, then it jogs my memory.

I have been using either napa universal or travellers universal since my first change. No issues there.

And no need to change the filter every time either. I would unscrew and drain it, but put it back on if you are changing the oil frequently. Those filters arent cheap. Use it for the 200 hours (or 100hrs I cannot remember) that its good for regardless of how many times you change the oil.

 

[art]

Because it is a gear drive the oil quality is important and one we use that absorbs the most amount of moisture is the Case Hytran oil. I would flush with any cheap oil! Then change to something better. I would not continue to run it with the moisture during the winter as the hard steering and slow response is from lack of good oil flow!! You are staving your pump and it will fail!!!

 

[Tx Jim]

Be sure trans case filler cap breather hole is open IE not plugged.

 

[k0ua]

Be sure trans case filler cap breather hole is open IE not plugged.

On that particular model the filler cap is solid and on the back. The vent is under the the seat. Black rubber, looks like a shepards crook.

 

[k0ua]

Be sure trans case filler cap breather hole is open IE not plugged.

On that particular model the filler cap is solid and on the back. The vent is under the the seat. Black rubber, looks like a shepards crook.