Performance Friction RH665 Super DOT 4 Racing Brake Fluid (500mL)

High-performance and racing brake fluid. Normal viscosity. 363°F wet boiling point.

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  • Dry Boiling Point = 325° C (617° F)
  • Wet Boiling Point = 184° C (363° F)
  • "Super" DOT4 (exceeds DOT5 specs)
  • Normal viscosity
  • 500mL bottle

Racing brake fluid with the highest guaranteed minimum dry boiling point (ERBP) of any DOT4 Brake Fluid

Performance Friction RH665 Racing Brake Fluid is a cut above other racing brake fluids and it’s specially formulated for racing applications where braking systems operate at very high temperatures. The complex mixture of Glycol Ether Borate Esters and Polyalkylene Glycol Ethers, together with advanced corrosion inhibitors, antioxidants, and other modifiers, result in an exceptional brake fluid with not only a very high boiling point, but which also conforms to all DOT4 specifications. All this while maintaining its class-leading viscosity, lubricity, and compressibility performance at extreme temperatures to ensure braking system reliability, performance, and a rock hard pedal.

RH665 has the highest guaranteed minimum dry boiling point (ERBP) of any DOT4 Brake Fluid, 325°C, to guard against vapor lock and give a rock hard pedal even under extreme racing conditions. Many manufacturers quote boiling points, but don’t be deceived - this isn’t the minimum specification that you could receive and can simply be the result of a single test sample. Typical values for RH665 are invariably higher than 325°C, and the same applies to wet boiling point where RH665’s is guaranteed to be above 184°C, with typical values much higher and equal to or better than other leading brands.

Normal or Low Viscosity? For dedicated track or race cars a Normal Viscosity fluid is suitable even if the factory fluid was a Low Viscosity (emphasis on "dedicated"). At track temperatures all types of brake fluid thins out and the viscosity becomes closely comparable. A NV fluid will always be slightly thicker than LV but the viscosity is close enough that you won't likely notice a difference at track temps. For mixed street-track or full road use you should use whichever fluid came from the factory. At cooler temps the viscosity difference between Normal and Low is very large. To maintain proper ABS and DSC operation you must use the appropriate fluid. Cars with DSC use the Low Viscosity; cars without DSC (or with ASC+T) use Normal Viscosity. You have DSC if you have the "DSC" button on your dash or center console.

RH665 can safely be mixed with other DOT4 brake fluids, however this will degrade the exceptional properties of RH665.

RH665 isn’t suitable for use in contact with magnesium components or in mineral oil based systems.

For best results bleed the system with fresh fluid before each event and when the brakes have been excessively hot and/or the conditions are especially humid. Always follow the vehicle manufacturer's recommendations.

Sold in 500mL bottles for maximum freshness.

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