RWD Racing Brake Fluid is not like any other brake fluid. Developed for motorsport racing applications, their proven formula is engineered to excel at very high operating temperatures. It must have a high boiling point to avoid vaporising in the lines. Vaporisation is a problem because vapour is compressible and negates hydraulic fluid transfer of braking force. RWD Mineral Oil This is a petroleum based brake fluid. Mineral oil has a stable lifespan and will not absorb water like Glycol based fluids. Any water entering a mineral oil system forms pockets and may lead to corrosion. It is essential that mineral oil brake systems are flushed every 12-18 months to prevent any long term damage. Dot 4 Racing Brake Fluid With a boiling point well in excess of 300 degrees, fluid boil and vapour lock should be a thing of the past. The low viscosity of the Racing Brake Fluid is essential to ensure a good bleed, lubricity is vital for system efficiency and compression, giving superior performance every time you pull on the brake lever. RWD brake fluid conforms to DOT 4 specifications and is suitable for all Glycol based systems. It is designed for racing applications but can be used as a direct replacement for standard brake fluid. Brake fluid is not considered a 'top up' fluid. If it is low, there is usually a problem. Brake fluid level in the master cylinder will drop as pads wear and the pistons extend further to compensate. This added fluid may need to be removed when renewing pads. Overspill from pushing back pistons should be avoided, because glycol based fluids will quickly lift or strip paints and other coatings on contact. Brake fluid may also be low because of a leak, which could result in a loss of hydraulic pressure and consequently, a significant loss of braking ability.