What is Brake Fluid?
Brake fluid is a hydraulic fluid used in vehicles’ braking systems. Its main job is to transfer force into pressure, helping your car stop when you press the brake pedal. It flows through brake lines, amplifying the force from your foot to the brake pads or shoes, which then press against the wheels to slow or stop the vehicle.
Types of Brake Fluid:
There are several types, mainly classified by their DOT rating (Department of Transportation).
- DOT 3: Common in most vehicles; glycol-based and absorbs moisture over time.
- DOT 4: Similar to DOT 3 but with a higher boiling point—used in newer cars and performance vehicles.
- DOT 5: Silicone-based, does not absorb water; used in military or classic vehicles (not compatible with DOT 3 or 4).
- DOT 5.1: Glycol-based like DOT 3 & 4, but with higher performance for modern ABS systems.
Key Properties:
- High boiling point: Prevents vapor formation at high temperatures.
- Low freezing point: Ensures reliable braking in cold conditions.
- Corrosion resistance: Protects metal brake components.
- Lubrication: Keeps seals and moving parts working smoothly.
Maintenance Tip:
Brake fluid should be checked regularly and changed every 2–3 years (or as per your car manufacturer’s recommendation). Contaminated or low brake fluid can lead to soft brakes, reduced stopping power, or complete brake failure.