| abstract |
Non-flammable hydraulic fluids which are particularly useful for replacing existing hydraulic fluids in hydraulic systems employing acrylonitrile-butadiene rubber and Viton or PNF seals are disclosed. The non-flammable hydraulic fluids of the present invention comprise a fluorinated chlorotrifluoroethylene oil, an aliphatic ester, a liquid polyester or polyether, a hydrocarbon oil having a low wax content, and a phenolic antioxidant. The chlorotrifluoroethylene oil is present in an amount of at least about 75% by volume of the hydraulic fluid. Such hydraulic fluids are useful in applications where the flammability of existing fluids poses a significant risk of combustion or explosion due to the possibility of leakage of the fluid from the hydraulic system. |