Brake Fluids | HYDRAULAN^®

The absorption of water into the brake system from the environment can never be totally prevented. On average, the brake fluid in a vehicle absorbs up to 1.5% water per annum. As the water content of the brake fluid increases the boiling point of the brake fluid decreases. During braking the heat of friction can heat the brake cylinders and the brake fluid to temperatures in excess of 150 °C. If the boiling point of the brake fluid is exceeded vapor bubbles form in the brake fluid, which, unlike liquids are compressible. When this happens a failure known as “vapor lock” occurs and the force applied to the pedal is not transmitted to the brake cylinders. Because of their high boiling points and chemical properties HYDRAULAN^® prevents the formation of bubbles and this potential failure of the brake system.

Braking takes place in fractions of a second. The hydraulic force generated through the actuation of the brake pedal needs to be transmitted to the wheel brakes instantly. Lower viscosity fluids transfer the force more readily than higher viscosity fluids and therefore it is essential that the brake fluid does not become too viscous at lower temperatures. HYDRAULAN^® brake fluids have an extremely low viscosity, particularly at low temperatures and therefore give optimal brake responsiveness.

Corrosion within the brakes system, leads directly to slower responsiveness, can cause blockages in the system or in the worst case lead to the integrity of the sealed brake system being broken. HYDRAULAN^® contains highly effective additives which reliably protect the various metals in the braking system (e.g., steel, cast iron, aluminum, brass and copper) against both oxidation and corrosion.

Lubrication to prevent both friction and abrasion in the brakes system maintains responsiveness, reduces wear and prevents heat build-up in the brake system. By simulating braking under extreme conditions and by endurance testing of braking systems HYDRAULAN^® has proved its excellent lubricating performance.

Elastomer cups are used to seal the brake cylinders against loss of fluid in the gap between the piston and the cylinder. HYDRAULAN^® has been specially formulated to allow for slight swelling of the elastomer cups to ensure a reliable seal and to prevent the loss of fluid.

Under extreme operating conditions the brake fluid can reach temperatures in excess of 150 °C. Despite this high thermal loading the brake fluid must remain chemically and thermally stable. The use of high-quality glycol ester components and special inhibitors in HYDRAULAN^® ensures maximum optimization of chemical and thermal stabilities.

The brake system is one of the most important safety features of a vehicle and therefore needs to meet the very high standards required by the automotive manufacturers, the automotive industry and automotive safety legislation. Therefore brake fluids must meet stringent specifications and are often also officially approved by the automobile manufacturers.

BASF'S HYDRAULAN^® are specifically designed to meet and exceed the stringend and manifold requirements across the industry globally.

FMVSS: Federal Motor Vehicle Safety Standard

The FMVSS criteria are minimum requirements for vehicle safety in the U.S. The brake fluids requirements are defined by the DOT classification.

• FMVSS No. 116 DOT 3
• FMVSS No. 116 DOT 4
• FMVSS No. 116 DOT 5 Silicon base
• FMVSS No. 116 DOT 5.1 Non-Silicon base

SAE: Society of Automotive Engineers

SAE International is the leader in the research and development of standards for the transport industry in the U.S.

• SAE J 1703
• SAE J 1704 Standard
• SAE J 1704 Low Viscosity

ISO: International Organization for Standardization

The ISO coordinates the issuing of standards throughout the world with the aim of creating international standards.

• ISO 4925 Class 3
• ISO 4925 Class 4
• ISO 4925 Class 5-1
• ISO 4925 Class 6
• ISO 4925 Class 7

JIS: Japanes Industrial Standard 

JIS sets the Japanese industrial standard.

• JIS K 2233 Class 3
• JIS K 2233 Class 4
• JIS K 2233 Class 5
• JIS K 2233 Class 6