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Foamy hydro oil

Posted: Sat Jul 20, 2013 6:44 pm
by Slickwilly1976
I was looking at the fluid I'm my kubota I just bought and it was real foamy. Anyone know why? Mixed with wrong fluid maybe? Who knows what the p.o. Did

Re: Foamy hydro oil

Posted: Sat Jul 20, 2013 9:41 pm
by Eugene
Answer is unknown. Could be water or air trapped in the hydraulic fluid.

I would just drain the complete hydraulic system and replace filter(s) and with recommended oil. Might be expensive.

Re: Foamy hydro oil

Posted: Sat Jul 20, 2013 10:07 pm
by Slickwilly1976
23qts expensive
My book says sae 80 gear oil I went looking and found 80-90 gear lubricant.
Is that the same.

Re: Foamy hydro oil

Posted: Sat Jul 20, 2013 10:09 pm
by Rudi
Yup.. SAE80 wt falls into the 80-90 Gear Lube description. That is what I get from Case for my Cubs.

Re: Foamy hydro oil

Posted: Sat Jul 20, 2013 10:25 pm
by Slickwilly1976
Good deal thanks
I dread haveing to buy so much
Oh the joys of old tractors
Never offer a stupid price for a old tractor.....they may take it.

Re: Foamy hydro oil

Posted: Sun Jul 21, 2013 2:47 pm
by Rudi
Yeah but as Ollie used to say .... they are still a lot cheaper than the new stuff and built a heck of a lot better :D

Re: Foamy hydro oil

Posted: Sun Jul 21, 2013 3:49 pm
by Slickwilly1976
You got that right

Re: Foamy hydro oil

Posted: Thu Jul 25, 2013 5:14 pm
by Smokeycub
What kind of Kubota is it? I can't imagine using 80-90 wt hydraulic/gear oil. Foaming sounds like water in the hydraulics to me.

Re: Foamy hydro oil

Posted: Thu Jul 25, 2013 6:03 pm
by Mr E
Smokeycub wrote:What kind of Kubota is it? I can't imagine using 80-90 wt hydraulic/gear oil. Foaming sounds like water in the hydraulics to me.


I agree. Typically, hydraulic oil is rather thin by comparison.

Re: Foamy hydro oil

Posted: Thu Jul 25, 2013 7:41 pm
by Eugene
Agree with the other guys. 80 wt is unusually heavy for hydraulic oil. Can't imagine the hydraulic system working in cold weather.

Suggest rechecking your source material.

Re: Foamy hydro oil

Posted: Thu Jul 25, 2013 9:26 pm
by Rudi
I agree. 80-90 wt is too heavy for hydraulic use.

Is the transmission one that calls for hydro or gear oil? If hydraulic oil you want to look at what Kubota uses although Hy-Tran, Hy-Tran Ultra, Perma-Tran, Ultra-Tran all are pretty well applicable to them also or so I was told by our New Holland dealer.

Re: Foamy hydro oil

Posted: Sun Jul 28, 2013 3:37 pm
by Slickwilly1976
The manual says use 80 weight gear oil. Same resivoir for trans and hydro. All I can find is 80w90. I ask a guy who use to worked at the jd kubota dealer here and he said that was right. What's in it now is almost clear and REALLY greasy. I do t know what it is. I whines when i raise and lower it. It has a internal screen filter not a spin on. It holds 23 quarts. It's a kubota l1500dt.

Re: Foamy hydro oil

Posted: Sun Jul 28, 2013 4:59 pm
by Rudi
Here is my take on it.

Do what the manual tells you to do. If it calls for SAE 80wt gear oil in the tranny and the hydro then that is what you need to put in it. Otherwise you risk damage to the tractor.

I know that in crawlers and such the hydro fluid is 30, 40, 50wt oil so if the system is designed for it, then that is what should be used.

Re: Foamy hydro oil

Posted: Sun Jul 28, 2013 6:29 pm
by Slickwilly1976
I think it's got a universal thinner fluid in it now. I don't want to tear something up by switching back in forth but I'm going to try the 80w90 and see if the whine stops

Re: Foamy hydro oil

Posted: Sun Jul 28, 2013 6:47 pm
by Rudi
Before you change it out, is it a sealed system? If so could the whine possibly be air caught in the system? Maybe all it needs is to be bled?

Have you talked to a Kubota dealer at all? Might be worth a shot on the toll free if you don't have one close. :idea:

Grasping here :roll: