Hydraulic Fluid for Military Equipment

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Hi guys, new member here. I have a surplus military excavator and I need to top off the hydraulics. The lubrication manual uses all military nomenclature for the fluids. From what I can tell it uses basic 10wt oil for the hydraulics. The order states use OE/HDO (MIL-L-2104) for the system down to 10 degrees F. So my question is what civilian equivalent I should use or can I safely mix in AW32 or Mobil DTE24 with the existing fluid since both of these are 10wt and are specifically rated for hydraulic use? Thanks!
 
Here's what I came up with on Google:

A wide range of U. S. Military (MIL) Specifications exist for the use of the U. S. Department of
Defense and other Government agencies. The approval and maintenance of a MIL – lubricant
qualification not only requires manufacture and testing of a fixed additive and base oil
formulation, but a “Manufacturing Facility Survey” is also required. All U.S. Military
specifications are now issued as Performance Specifications designated as MIL-PRF.

MIL-PRF-2104G
SAE 10W, 30, 40 & 15W-40
APICG-4, CF, CF-2 & Allison C-4
Most commercial HDMO's meeting these requirements would also meet API SJ.a

MIL-L-2104E (Superseded March 1992)
Approximate equivalent of API Service Classification CD-II in diesel engine performance, while
testing in spark-ignition engine tests suggests a petrol engine performance in the area of API SF.

MIL-L-2104D (Superseded August 1988)
Appropriate equivalent of API Service Classification CD with gasoline engine performance which
fell between API SD and SE. Passing performance in DDA 6V-53T, Caterpillar TO-2 and Allison C-
3 tests also required.

MIL-L-2104C (Superseded April 1983)
Approximate equivalent of API Service Classification CD/SD. MIL-L-2104B (Superseded
November 1970) Required performance in the 1-H, L-38 and LTD engine tests Prior to MILL2104A,
several Military Ordnance and U.S.

Army Specifications were in place. Details are as follows:
MIL-O-2014 (ORD) - issued August 1950, Superseded by MIL-L-2104A, February 1954. U.S. Army
2-104B - issued May 1943, Superseded by MIL-O-2104 (ORD), August 1954. Supplement 1
applied to U.S. Army 2-104B but was never written into the specification itself. This “Qualified
Products List” (QPL) listed oils which were tested against higher sulfur fuel.
Supplement 2 applied to U.S. Army 2-104B but was never written into the specification itself.
This OPL listed oils which were also approved under Caterpillar Superior Lubricants (Series 2).
U.S. Army 2-104A and 2-104 were issued between 1941 and 1943, and were superseded by U.S.
Army 2-104B, May 1943.

Note: U.S. Army 2-104B, Supplement 1 was a higher performance level than the subsequent
MIL-O-2104 (ORD) and MIL-L-2104A Specifications and “Supplement 1” became an accepted
industry guideline until the issue of MIL-L-2104B in December 1964.

Looks pretty broad to me...
 
a 10 weight engine oil is about an ISO 32 hydraulic oil. I would move up to at least an ISO 46 hydraulic oil if it was my machine...unless operated in extreme cold weather. Mobil DTE is a decent choice.
 
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Cat TO-4 10w hydraulic oil is what you want. If you cant get that a 10w-30 HDEO would suffice for top off.
You shouldn't really use standard AW hydraulic oil like Mobil DTE as that does not meet the requirements.
 
In a hydraulic system, a typical AW hydraulic oil is more than adequate.
It doesn't quite require a TO4 transmission oil, and there is no advantage to AW hydraulic oil.
 
I'm in the same boat with a surplus MMV telehandler. Manual calls for basically 10w-30 in the hydro system and transmission for most conditions but it's significantly colder here. They do have an option for DexIII in both but I'm looking for an alternative to Dex in hydraulic system as it takes 40+ gallons.
 
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