Moisture in hydraulic/transmission oil

geneP · Dec 8, 2004

I recent bought a Case-IH tractor with 500 hours on it. The hydraulic/transmission oil looked clean and clear on the dipstick, but when I disconnected a tool from the aux hydraulics the oil that dripped out looked milky/tan. I took a sample of about a pint out and let it set for a day and it has returned to its brown oily look. I took the fill plug out to look for rust, etc and although the plug wasn't rusty on the bottom, there were drops of moisture on it's concave underside leading me to believe there is moisture in the oil from condensation. The tractor was in a metal building but there is enough moisture here in the deep south that the concrete floor stays wet a lot. For those of you who have experience in this area, do I need to drain and refill the oil and filter? (it holds 9 gallons) If yes, do I need to run some cheaper oil through it to try to get more of the old oil and moisture out? Thanks in advance for your thoughts.
Gene

SkyPup · Dec 8, 2004

I agree with your thoughts.

Running some cheap clean oil through and running it for ten hours or so to emulsify the contaminated hydro fluid would be a good idea (dumping it while it is hot). I believe the max water concentration is around 0.5% for hydro oil.

This is always a reoccuring problem in places where the humidity is high and temperature changes rapidly, like all over most of the South.

Zork · Dec 8, 2004

Changing the oil will give you some place to start your history with this machine. Your bound to get some moisture through the vent of the case. Working it so the oil and case get good and hot should take care of any risidual or minimal moisture /forums/images/graemlins/grin.gif

Rch · Dec 8, 2004

geneP, make sure any boot and seals are intact where shift levers enter the transmission and the transmission/differential breather ( usually at a high point on the differential) is not broken so water can get in. /forums/images/graemlins/wink.gif

geneP · Dec 8, 2004

"Working it so the oil and case get good and hot should take care of any risidual or minimal moisture"

Maybe one reason so much moisture is in there is because of the 500 hours (known history) on it in 15 years. Obviously it hasn't been run much to cook the moisture out. Another problem is that all the grass is cut and the ground is wet so I really don't see me putting 10 hours on it till summer. I don't want the moisture sitting in there all winter. I can just visualize rust spots building up on machined surfaces.

"make sure any boot and seals are intact where shift levers enter the transmission and the transmission/differential breather ( usually at a high point on the differential) is not broken so water can get in."

This transmission has the shift levers going into the side, so it must be sealed by o-rings or lip seals. I went ahead and drained the old fluid and it was "gulping" until I opened the fill plug...Maybe I need to look for a vent.

Thanks for your thoughts. I'll get some oil and flush it.

Phred · Dec 8, 2004

I do oil analysis on my tractors/trucks to avoid this.
The idea is to sample the oil to let you know if it needs to be changed, and also gives you an idea of engine wear.
I use blackstone labs but I suspect that other companies offer similar service.
http://www.blackstone-labs.com/

They will send you a sample kit for free. Get a big vet syringe without a needle and a length plastic hose. Slip the hose over then end of the syringe and then you can sample the oil out of a crank case, diff, or tranny.

Send them a sample and $20 and they will send you a report via email or snail mail.

$20 may sound steep but the dealer gets $100 for the tranny oil alone in my tractor. That does not include my labour or the filters, just the oil. So an oil analysis that allows me to extend the run time on that oil, without harming the machine, saves money in the end. The key is knowing when it really needs to be changed.

Fred