Compatible Hydraulic Fluid ?

[LD1]

I use the traveller universal stuff from tsc. Never had any issues in any of the equipment it gets ran in.

Only thing I source from kubota is the air filter and the hydraulic oil filter. Everything else is aftermarket.

 

[bocash3]

Today, I found that both Tractor Supply and Auto Zone had UDT compatible hydraulic fluid. Each had on the back of the container that they were OK for Kubota. I bought a gallon at AZ because TS only had 2-gallon containers.

 

[Soundguy]

As said, Kubota doesn't pump or refine any oil.. Its all thru custom bottelers that they have a Kubota brand oil.

 

[KYKub]

I, too, have grudgingly purchased Kubota hydraulic fluid after longingly studying the cheaper stuff in TSC and Rural King. I noticed that their "premium" fluid is advertised as comparable with Kubota UDT; however, my G1900 calls for "Super" UDT. Is there any difference? I don't buy it by the drum like some of you guys, but I still resent being coerced unnecessarily to buy branded anything.

Thanks. Jeff

 

[rScotty]

As I read it, the original question was whether different brands of hydraulic oil are compatible with each other.

We oughta be able to answer that. Think about it.....lots of tractors have hydraulic outlets so that they can power attachments - attachments which can be rented at rental shops just about anywhere. Every one of those attachments has mystery oil in it when it comes to you, so nobody who uses these implements has the slightest idea of what kind of oil is getting mixed their tractor's hydraulic oil. You just hope it's at the least oil of some kind....and not too much water and not too dirty. Probably most of it is engine oil. BTW, for lots of years the John Deere commercial equipment specified 10w-30 engine oil as their preferred hydro/transmission oil. That's what the manual for my 2006 JD310SG calls for.

I'm thinking that if mixing hydraulic oils was a problem we would have no doubt about it by now. With all the people renting equipment and mixing this and that and who knows what into their common hydraulic oil by now any downside would be common mechanical knowledge. Instead,what we have are lots of opinions on oil but very little or no repeatable examples where oil incompatibility has caused a problem. Maybe the oil companies are right and their products really are compatible. It looks to be true.

My opinons - Are some oils better than others? Well....., probably yes. Does mixing one kind of hydro/transmission oil with another or with motor oil cause a problem? Probably not......at least there's no hard evidence that it does and lots that it doesn't.
Do I mix oils in my own machines? Certainly not! I intend to keep my machines for 10,000 hrs, so we buy premium hydraulic/transmission oils, keep them clean, and figure the cost is cheap enough if all it does if it postpones wear by a thousand hours. But then I also buy the occassional lottery ticket.

Good Luck beats Good Planning,
rScotty

 

[Soundguy]

I'm sure dilution ratio plays a big part if you mixed a watery engine oil into a premium UDT system. IE. whats 20 oz oil in a 13g system.. etc.

all depends on how much..


I agree though.. limited mixing from implements will be just that.. and heck.. if lucky.. you can keep most of it int he lines anyway.

 

[Silvic]

I am against mixing types. In another industry, aviation, back in the late 70's there was a failure of grease when two non-compatible greases were mixed and lost all structure that made it grease. Lost an aircraft as a result.

I know this is a tractor not an airplane but the possibility of loss of properties due to non compatible fluids is the same. Of course you are talking to someone that when he changes the hyd fluid in his machines he changes the remnants of the fluid that is in the attachments by flushing them as well. It took a bit over 33 percent more fluid to do that but that would have been 33% dirty fluid that would have circulated if it had not been done.
Your choice but ...................:thumbdown:

 

[IslandTractor]

I am against mixing types. In another industry, aviation, back in the late 70's there was a failure of grease when two non-compatible greases were mixed and lost all structure that made it grease. Lost an aircraft as a result.

I know this is a tractor not an airplane but the possibility of loss of properties due to non compatible fluids is the same. Of course you are talking to someone that when he changes the hyd fluid in his machines he changes the remnants of the fluid that is in the attachments by flushing them as well. It took a bit over 33 percent more fluid to do that but that would have been 33% dirty fluid that would have circulated if it had not been done.
Your choice but ...................:thumbdown:

You must have a lot of attachments. I use close to 15 gallons to change hydraulic fluid in my tractor. I've got a BH and grapple and topping lift cylinder but cannot imagine there is more than a gallon or two combined in the hoses and cylinders of the attachments. 10% used fluid that doesn't appear dirty at all seems no big deal especially with a new filter. I have always thought the purpose of fluid changes was simply to replace additives as the filter is supposed to keep the fluid clean. In my case even close to time of fluid change (200 plus hours) the fluid is so clear that it is hard to read on the dipstick.

 

[Silvic]

You must have a lot of attachments. I use close to 15 gallons to change hydraulic fluid in my tractor. I've got a BH and grapple and topping lift cylinder but cannot imagine there is more than a gallon or two combined in the hoses and cylinders of the attachments. 10% used fluid that doesn't appear dirty at all seems no big deal especially with a new filter. I have always thought the purpose of fluid changes was simply to replace additives as the filter is supposed to keep the fluid clean. In my case even close to time of fluid change (200 plus hours) the fluid is so clear that it is hard to read on the dipstick.

Don't know what a bunch is but I could be accused of having that. :laughing:

The interesting thing was the implements that have cylinders on the ends of hoses (no or little return flowback to the sump) had what to me was an amazing amount of moisture in the fluid (milky like). Of course the implements that have open flow, (motors and the like) have the fluid circulating all the time and any fluid that was in the system is gone in several seconds after it is turned on as it returns to the tractor sump. The oil analysis that was done on the main sump sample showed very good quality with no moisture issues. The fluid just never got a chance to circulate and be heated and expunge the moisture that accumulates over time. Some of the fluid in your BH cylinders is probable as old as the cylinder if you have made no effort to drain and clean on some periodic cycle. My three way blade had almost 2 gallons in it. The chipper a lot more. BH probably had the least of all of them even with all of its cylinders.

 

[100 td]

For general use of implements, every time a cylinder is extended, the cylinder is filled with new oil from the valve block (including existing oil in the hose/pipe), and the oil on the other side of the cylinder is returned to the sump. Then the same happens when it's retracted. The only way a cylinder has old oil in it, is if the volume contained in the long lines to the cylinder is greater than the volume of the cylinder. I'll take a punt on saying the volume of the cylinders will hold more than the hoses on most loaders & hoes, perhaps an extender hoe bucket ram may be less, but unless it's measured, then I'm just guessing for the lot, but I'll take the punt anyway. I will have to measure mine some day!