Hydraulic oil? fluid? Mil spec 5606?

   / Hydraulic oil? fluid? Mil spec 5606? #1  

nepa

Silver Member
Joined
May 31, 2013
Messages
125
Location
Forest City, PA
Tractor
Mitsubishi 180D, Jinma 284 sold, Kubota BX2660, IH Cub, Case 580CK, Minneapolis Moline 4 Star (sold), TYM 574, Furukawa FX-040
My Hiniker snow plow broke a bracket and I wound up removing a hydraulic ram to make repairs. The fluid in the system is a rich green and Hiniker says to use their "hydraulic oil" or other meeting mil spec 5606. Looking up mil spec 5606 says that it is petroleum based. I suppose that petoleum based means something like tranny fluid as opposed to aw hydraulic fluid which is alcohol based. Does anyone have knowledge of Mil spec 5606?

My Chinese tractor calls for motor oil in the hydraulic system. As motor oil can get thick in cold weather I usually add tranny fluid which is made from the same base oils. Many people say to use hydraulic fluid but I do not feel this is right since it is hydroscopic and attracts water which can not be good for the system especially since the mfr does not call for it.

Thanks.
 
   / Hydraulic oil? fluid? Mil spec 5606? #2  
   / Hydraulic oil? fluid? Mil spec 5606? #3  
My Hiniker snow plow broke a bracket and I wound up removing a hydraulic ram to make repairs. The fluid in the system is a rich green and Hiniker says to use their "hydraulic oil" or other meeting mil spec 5606. Looking up mil spec 5606 says that it is petroleum based. I suppose that petoleum based means something like tranny fluid as opposed to aw hydraulic fluid which is alcohol based. Does anyone have knowledge of Mil spec 5606?

My Chinese tractor calls for motor oil in the hydraulic system. As motor oil can get thick in cold weather I usually add tranny fluid which is made from the same base oils. Many people say to use hydraulic fluid but I do not feel this is right since it is hydroscopic and attracts water which can not be good for the system especially since the mfr does not call for it.

Thanks.

Where did you get the notion that AW hydraulic oils are alcohol based?
 
   / Hydraulic oil? fluid? Mil spec 5606? #4  
Mil spec 5606 is a mineral (petroleum) based oil. It is used in the hydraulic systems of
aircraft.(primary use) Not all aircraft use the mineral oil. Most of your large commercial aircraft use
a phosphate ester type of hydraulic oil. The two types are not compatable at all. I have
used both. General Aviation and Airlines. I prefer working with the 5606 as it does not
bother my skin.
I must say tho, I don't know how many pink underpants I have had due to getting the
red 5606 on them...lol..
 
   / Hydraulic oil? fluid? Mil spec 5606?
  • Thread Starter
#5  
Sorry about the generalization of all hydraulic oils being hygroscopic (another mistake I made) I guess that I was thinking brake fluid. Kaliburz link is very informative and solves my problem. Thanks.

Characteristics of common braking fluids[1] Dry boiling point Wet boiling point Viscosity limit Primary constituent
DOT 2 190 °C (374 °F) 140 °C (284 °F) ? Castor oil/alcohol
DOT 3 205 °C (401 °F) 140 °C (284 °F) 1500 mm2/s Glycol Ether
DOT 4 230 °C (446 °F) 155 °C (311 °F) 1800 mm2/s Glycol Ether/Borate Ester
DOT 5 260 °C (500 °F) 180 °C (356 °F) 900 mm2/s Silicone
DOT 5.1 260 °C (500 °F) 180 °C (356 °F) 900 mm2/s Glycol Ether/Borate Ester
Still, the shop manuals for much of my older equipment, such as my 70s vintage back hoe and wheel loader, reccomends changing the hydraulic fluid regularly due to water absorption or else it starts to look like cocoa.
 
   / Hydraulic oil? fluid? Mil spec 5606? #6  
Meyer Snow Plows used to use Mil 5606 fluids. Not sure if they still do today or not.

5606 is a very thin fluid that works good for intermittent use in snow plow applications.
 

Tractor & Equipment Auctions

Ingersoll Rand 30T (A34127)
Ingersoll Rand 30T...
TOOL BOX (A36702)
TOOL BOX (A36702)
Construction Trailer Specialists 40? Steel Hopper Bottom Trailer (A35780)
Construction...
5 16FT GATES (A36702)
5 16FT GATES (A36702)
1996 International 9200 Truck (A36338)
1996 International...
35 TON EQUIPMENT TRAILER (A36465)
35 TON EQUIPMENT...
 
Top