Brake fluids are classified by both “dry boiling point” and “wet

Fluid                 Dry ERBP (°F)           Wet ERBP (°F)         Viscosity Limit              Chemical

Grade               @ 0.0% H2O          @ 3.7% H2O          (Cp @-40°F)                       Composition

 

DOT 3               401                          284                          1500 mm2/s           Glycol Ether Based

 

DOT 4               446                          311                          1800 mm2/s           Glycol Ether / Borate Ester

 

DOT 5 (SSBF)   500                         356                          900 mm2/s              Silicone Based

 

DOT 5.1            500                         356                          900 mm2/s              Borate Ester/ Glycol  Ether