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Can I safely use this hydraulic oil?

Willof72

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Joined
Mar 27, 2026
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3
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Pennsylvania
My Kubota KX91 excavator takes a ISO46 hydraulic fluid, but my son has an overabundance of Cat Hydo Advanced 10 hydraulic oil (SAE 10W). Can I use this safely or would it not do good things to my machine? TIA
 

Nige

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Cat 10 aw is zinc iso46 is usually zinc free/different additives?
To my knowledge a common-or-garden ISO46 will have a zinc-based anti-wear package.
Only something like Hitachi 46HN, and its equivalent from all the major oil companies, is zinc-free/ashless.

Certainly both the Shell & Mobil oils in the illustration posted by Tyler, which I assume is the correct one for the machine, have zinc-based additive packages.
 

IceHole

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Aug 14, 2023
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To my knowledge a common-or-garden ISO46 will have a zinc-based anti-wear package.
Only something like Hitachi 46HN, and its equivalent from all the major oil companies, is zinc-free/ashless.

Certainly both the Shell & Mobil oils in the illustration posted by Tyler, which I assume is the correct one for the machine, have zinc-based additive packages.
And that no zinc is more a recent thing.
The 1997 ZX200 we had speced Rando HDZ as one suitable oil.

I don't get why some spec it and others act like it's the devil.

It's like nitrited coolant. CAT specs it for their stuff. Others say nitrite free.

What's special in a CAT that a Volvo is different? Only so many materials to make cooling systems from.
 

Nige

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I see a lot ashless or zinc free iso46 like Case Hytrans.
From my perspective that is a specialized oil recommended for specific applications by a group of OEMs that obligate the use of an oil of that type. My earlier example of Hitachi 46HN falls into exactly the same category. Note my earlier comment "a common-or-garden ISO46" oil, by which I meant a hydraulic oil - my apologies for that omission.

I must admit to being somewhat confused at this point.

1. The OP asked a question regarding hydraulic oil for a specific make/model of excavator
2. The recommended hydraulic oils shown in the OEM manual for that machine (thanks Tyler) all have a zinc-based anti-wear package.
3. The alternative oil (Cat Advanced HYDO 10) regarding which the OP asked his question also contains a zinc-based anti-wear package. "My Kubota KX91 excavator takes a ISO46 hydraulic fluid, but my son has an overabundance of Cat Hydo Advanced 10 hydraulic oil (SAE 10W)"

Where and/or how did zinc-free oils come into the discussion.?
 

Welder Dave

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Girls will be boys and boys will be girls
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