Breaking the Misconception: Understanding the Unique Chemical Properties of Brake Fluid

From the perspective of chemical composition, modern brake fluids are primarily synthetic products, formulated by combining base raw materials with functional additives.

Their core functions can be summarized in four key areas: energy transmission, transferring and hydraulically amplifying the mechanical force applied by the driver to the brake pedal and delivering it to the brakes; heat dissipation, absorbing and carrying away heat generated during braking; corrosion and rust protection, protecting metal components within the braking system from corrosion; and lubrication, providing lubrication for the brake master cylinder, wheel cylinders, and various seals.

Key Performance Indicators

High Boiling Point (Resistance to Vapor Lock):
At high temperatures, brake fluid may boil and generate vapor, resulting in vapor lock and reduced braking force. The dry and wet equilibrium reflux boiling points are key indicators used to evaluate the fluid’s high-temperature resistance and ability to prevent vapor lock.

Suitable Low-Temperature Viscosity:
Brake fluid must maintain good fluidity even at temperatures as low as -40°C, ensuring responsive braking performance in cold climates.

Rubber Compatibility:
Brake fluid must be compatible with the rubber seals used throughout the braking system and should not cause excessive swelling or shrinkage.

Metal Corrosion Protection:
Brake fluid must provide effective protection for various metal components within the braking system to help prevent corrosion.

Industry Applications

The Largest Market for Brake Fluid: Passenger and Commercial Vehicles

Passenger cars and commercial vehicles represent the primary application areas for brake fluid and account for the majority of the global brake fluid market.

Different types of vehicles have different brake fluid grade requirements. Standard passenger cars and light commercial vehicles typically use DOT 3 or DOT 4 brake fluids.

A New Growth Area for Brake Fluid: New Energy Vehicles

New energy vehicles, particularly electric vehicles (EVs), are creating new technical requirements for brake fluids. As electric vehicles are equipped with regenerative braking systems, brake fluids need to maintain stable viscosity and boiling-point performance across a wider temperature range.

Construction Machinery & Special-Purpose Vehicles

These vehicles and machines often operate in demanding environments and experience frequent braking. As a result, their applications place more stringent requirements on the thermal stability and metal protection performance of brake fluids.