Kubota AW46HD vs UDT

[B2710]

This for all the oil experts... broke a line on my KX040-4 excavator. Lost about half the hydraulic tank which is about 5gal. Sent the son to the dealer to get hydraulic fluid, they sold him UDT even with him telling them it was for an excavator and he refilled the tank. When I saw the bucket, I called the dealership and they claim no concerns as they do that all the time in their shop instead of opening a new bucket of 46 they would use UDT to replace lost fluid. Kubota online said to not mix them. Total capacity of the hydraulics is about 18gal so, less than a third is udt... do I make it a big deal and ask them to at least give me a couple of buckets of 46 to dump the tank or do what they say and run it?

 

[EPIC]

According to Chat GPT UDT is fine in KX-040…. But it also says not to mix with other fluid types.

I am cautious I would replace it all but that’s me.

 

[TheOldHokie]

This for all the oil experts... broke a line on my KX040-4 excavator. Lost about half the hydraulic tank which is about 5gal. Sent the son to the dealer to get hydraulic fluid, they sold him UDT even with him telling them it was for an excavator and he refilled the tank. When I saw the bucket, I called the dealership and they claim no concerns as they do that all the time in there shop instead of opening a new bucket of 46 they would UDT to replace lost fluid. Kubota online said to not mix them. Total capacity of the hydraulics is about 18gal so, less than a third is udt... do I make it a big deal and ask them to at least give me a couple of buckets of 46 to dump the tank or do what they say and run it?

AW46 is a plain monograde hydraulic oil with minimal additives.

UDT is a multi-function multigrade oil with a lot of additionsl additives.

They will mix fine but the additive package in the UDT will be diluted. Thats not going to be an issue in the excavator's dedicated hydraulic system but it would be in an HST tractor with a final drive, wet brakes and clutches that rely on those additives.

All that said I would not be happy with that dealer and future business would go elsewhere. I would alsi go to the local tractor supply and buy enough AW46 to drain and refill the excavator.

Dan

 

[GeoHorn]

I believe it will be just-fine…and no further action necessary. (The AW46 has actually been improved by the addition of UDT.)

 

[B2710]

I did pick up 2 buckets of Shell S2 Tellus iso 46, just hate to dump 300.00 of new oil down the drain...

 

[GeoHorn]

I did pick up 2 buckets of Shell S2 Tellus iso 46, just hate to dump 300.00 of new oil down the drain...

Take that back for refund. IMO

 

[TheOldHokie]

I did pick up 2 buckets of Shell S2 Tellus iso 46, just hate to dump 300.00 of new oil down the drain...

I understand your distress. You can go either way.

Which S2 Tellus did you buy? I thought you needed 18 gallons for tgat machine?

Dan

 

[B2710]

I understand your distress. You can go either way.

Which S2 Tellus did you buy? I thought you needed 18 gallons for tgat machine?

Dan

S2mx 46..... I think Kubota has that listed in the owners manual as an alternative. 18gal is system capacity, tank is 10gal... easy to dump the tank and refill, flushing the rest is hard.

 

[GeoHorn]

S2mx 46..... I think Kubota has that listed in the owners manual as an alternative. 18gal is system capacity, tank is 10gal... easy to dump the tank and refill, flushing the rest is hard.

edited…i’ve been wrong apparently.)

 

[B2710]

All, thanks for the input, I am likely ok with the 5 gals of UDT added to the system but it is a new 80k machine and when the OM and WSM both say AW46 and no mention of UDT, I think I have some reason for pause. I asked the service manager to put in writing that UDT is acceptable in my excavator.. absolutely refused, I asked them to submit the question to Kubota and they said no...

So, I submitted a question to Kubota customer service if it is ok to use UDT and here is the response...

"No. Kubota UDT (Universal Dynamic Tractor) and Super UDT2 fluids are generally formulated for agricultural tractors, RTVs, and mowers. In contrast, Kubota excavators and SVL compact track loaders (skid steers) use dedicated anti-wear (AW) hydraulic oils, such as Kubota HD32, HD46, or HD68. Using standard tractor UDT fluid in an excavator or SVL's hydraulic system can lack the specific viscosity needed for heavy-duty pumps, or worse, cause foaming and cavitation in construction-grade machinery and is not recommended.
Your machine was factory-filled with Shell Tellus S2M46. Kubota Super UDT/UDT-type fluid is not as the listed KX040-5 excavator hydraulic oil. A few hours of operation does not mean damage occurred, but Kubota's service position is to get the system back to the oil type specified for the KX040-5."

YMMV...

 

[TheOldHokie]

Using standard tractor UDT fluid in an excavator or SVL's hydraulic system can lack the specific viscosity needed for heavy-duty pumps, or worse, cause foaming and cavitation in construction-grade machinery and is not recommended.
Your machine was factory-filled with Shell Tellus S2M46.

So basically its a viscosity concern according to Kubota. I think thats pure CYA.

Standard UDT clocks in as a ISO VG 46 and SUDT2 would be VG 32. Thats straight frim the Kubota data sheets. Both are multi-grade formulations so in the Tellus S2 product line they would be the VX formulation which is part of why I asked.

But I am with you and Kubota - use the type of oil specified by the OEM.

Dan