HYDRAULAN^® Brake Fluids

1. Boiling Point

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.

2. Viscosity

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.

3. Corrosion Protection

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.

4. Lubrication

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.

5. Elastomer Compatibility

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.

6. High Temperature Thermal Stability

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.

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

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

HYDRAULAN^® 404

In the field of brake fluids BASF has developed a groundbreaking innovation! HYDRAULAN^® 404 is a tailor-made brake fluid for vehicles with electronic stability control systems (ESP^® and DSC). At low temperatures this brake fluid has an extremely low viscosity. This enables pressure to build up more quickly and the wheelbrakes to respond more quickly. Thus the pressure buildup at low temperatures of approx. –20°C is about 30% faster than with conventional DOT 4 brake fluids, so the high safety potential of ESP^® or DSC can be used to the full in winter road conditions. HYDRAULAN^® 404 exceeds the new ISO 4925, Class 6 specifications and impresses with a boiling point of at least 265°C, a wet boiling point of at least 175°C and a viscosity at –40°C of no more than 700mm2/s.

HYDRAULAN^® 406 ESI

Continuing to build on our long-established close partnership with the automotive industry, BASF’s latest innovation HYDRAULAN^® 406 ESI sets new performance parameters for a premium brake fluid.

Enhanced safety is provided by the product’s higher boiling points and its reduced low temperature viscosity. HYDRAULAN^® 406 ESI is a brake fluid that covers all the specifications of DOT 3, DOT 4, DOT 5.1 NON-SILICONE BASE and also exceeds international requirements for low viscosity brake fluids. With the continuing technological advancement of brake systems and automated safety systems, lubricity will become an essential  factor when selecting an appropriate brake fluid. Here, HYDRAULAN^® 406 ESI has been formulated to provide superior lubrication and therefore extend the durability of the whole brake system.