Brake fluids: this is what you need to know

A vehicle's braking systems are key elements in ensuring safety on the road. However, behind their performance and durability is a key component that often gets overlooked: brake fluids. 

In this article, we explore the fundamental role that brake fluids play in the protection and maintenance of brake systems, as well as their main characteristics.  

Why are brake fluids so important for the braking system?

Brake fluid works like a hydraulic fluid. In this case, it is responsible for transmitting the force from the brake pedal on to the brake pads, generating the necessary friction to stop the vehicle.

That's why brake fluids are essential for vehicle safety, performing multiple functions within the braking systems, made up of an intricate network of components that work together to stop vehicles safely and efficiently. These parts include pistons, rotors, calipers or hydraulic systems.

For everything to work correctly and extend the brake system's useful life, both maintenance and proper product formulation are important. Therefore, these fluids must be formulated with the following characteristics:  

• Be incompressible: for efficient transmission of pressure from your foot to the brakes.
• Have a high boiling point: to prevent the fluid from boiling from the heat produced during braking.
• Be compatible with other materials that make up the braking system, such as plastics, rubber or metals.
• Have a low freezing point that allows the fluid to remain liquid at low temperatures.

Types of brake fluids 

There are several types of brake fluids on the market to meet the needs of different vehicles: silicone-based fluids, mineral oil fluids, and the most widespread, which are glycol-ester based. The latter are translucent, very hygroscopic, have good lubricity, and high chemical and thermal stability, but have very low tolerance to water contamination.

Depending on their characteristics, brake fluids can be classified in different ways, although the most common way follows the norm of the US Department of Transportation, which identifies them as DOT 3, DOT 4, and DOT 5.1, the latter presenting the best properties.

To conclude this article, one last piece of advice: always remember to use quality products and change the fluid as regularly as recommended by the manufacturer. In Spain, brake fluids must be approved by the INTA (National Institute of Aerospace Technology) and these approvals must appear on the product label. 

At Repsol Lubricants, we have a complete catalog of brake fluids for your vehicle, click on this link to take a look and find the one that best suits your needs. See you soon!