The key components of stopping your vehicle are the brake pads, calipers, brake lines, master cylinder, brake pedal and brake fluid. You would consider regular inspection and maintenance mandatory on all of these safety related parts, yet changing your brake fluid has become the missing piece of the puzzle.
We have had “you must change your engine oil regularly” hammered into our heads to prolong the life of the engine and protect it from dirt and particles from damaging engine components. You also need to pay attention to servicing your brake fluid on a regular basis (most manufactures recommend every two years).
Brake fluid’s job is to carry pressure from the master cylinder, through the brake lines to the calipers, which puts pressure on the back of the brake pads that then clamp against the rotor to stop the vehicle. New brake fluid starts as an incompressible liquid and allows the brake system to function at peak design efficiency. The problem is over time it will become contaminated and become more compressible.
The better brake fluids typically are a glycol/ether chemical based fluid that has different hygroscopic rates (absorption of water from air) and boiling levels. As the brake fluid absorbs moisture over time, the incompressibility will deteriorate and the brake pedal travel will increase as pressure in the system is reduced, plus the boiling point of the brake fluid is also reduced. When overheated, brake fluid can boil which creates gas bubbles and the incompressibility can deteriorate to the point of having to pump the brakes to regain pressure (track enthusiasts can relate to this). Water saturated brake fluid will cause corrosion and increase viscosity (can harm ABS/ESP systems).
The rule of thumb, the higher the boiling point, the greater the hygroscopic properties and the higher frequency of maintenance. Most track cars using high temperature “race” brake fluids should change brake fluid or at least bleed the calipers after every race.
We only recommend AP Racing Brake Fluid and offer three options:
AP Racing Ultra 5.1 Brake and Clutch Fluid
AP Ultra 5.1 is AP Racing’s high performance non silicone based brake and clutch fluid. Recommended for use in the hydraulic brake and clutch systems of all cars, for which a non petroleum based fluid is specified. Suitable for high performance applications including vehicles fitted with ABS and ESP for road and track day use.
AP Racing Super 600 Brake Fluid
AP Racing Super 600 fluid has a dry boiling point exceeding 300°C and has been developed for racing applications where high temperatures are being experienced, e.g. when using carbon discs and the ultimate in brake fluid performance is required.
AP Racing PRF608 Brake Fluid
AP Racing PRF608 is suitable for all top levels of motorsport where abnormal temperatures are experienced. It should be noted that before using R3 fluid, any existing brake fluid should be drained completely from the brake system.