RH665 is a complex mixture of Glycol Ether Borate Esters and Polyalkylene Glycol Ethers together with advanced corrosion inhibitors, antioxidants and other modifiers. The result is an exceptional brake fluid with not only a very high boiling point but which also conforms to FMVSS 116 DOT 4 and maintains its class leading viscosity, lubricity and compressibility performance at extreme temperatures to ensure braking system reliability and performance and a firm and consistent pedal.
RH665 has the highest GUARANTEED minimum dry boiling Point (ERBP) of any DOT 4 Brake Fluid, 325°C, to guard against vapour lock and give a firm, consistent pedal, even under extreme racing conditions. Many manufacturers quote “typical” boiling points – do not be deceived. This is not the minimum specification that you could receive, it can be the result of a test on a single sample. “Typical” values for RH665 are invariably higher than 325°C. A similar situation applies to “wet” boiling point. RH665 is GUARANTEED to be above 195°C “typical” values are much higher and at least the equal of other leading brands.
The boiling point is of course not the whole story. With brake fluid it is essential to have the correct balance of properties to get a good overall result. Low viscosity is very important to ensure a good bleed. Low compressibility is essential for a firm pedal and lubricity is vitally important for efficiency, pedal return and life of the brake system.
BEWARE: Many racing brake fluids do not meet the viscosity requirements of DOT4.