| abstract |
This invention relates to a low water-sensitive hydraulic fluid composition which contains from about 20 to about 96 percent by weight of at least one borate ester as the base fluid and additionally, from about 2 to about 40 percent of a bis (glycol ether) formal. Such low water-sensitive hydraulic fluids are high boiling compositions which also have desirable properties at low temperatures, particularly viscosity, and thus are useful under a wide variety of climatic and operational conditions. |