What does Brake Fluid do?

Brake fluid is a crucial component in a vehicle's braking system, serving several important functions. The primary purpose of brake fluid is to transmit the force applied to the brake pedal by the driver to the brake components at each wheel, ultimately leading to the vehicle's deceleration or stopping. Here are the main functions of brake fluid:

1. **Hydraulic Transmission of Force:**

  - Brake fluid is a non-compressible hydraulic fluid. When the brake pedal is depressed, it creates hydraulic pressure within the brake lines. This pressure is transmitted to the brake calipers (in disc brake systems) or wheel cylinders (in drum brake systems) at each wheel.

2. **Transfer of Force to Braking Components:**

  - The hydraulic pressure generated by brake fluid causes the brake calipers to squeeze the brake pads against the brake discs (or the wheel cylinders to push the brake shoes against the brake drums). This friction between the brake components generates the necessary force to slow down or stop the vehicle.

3. **Heat Dissipation:**

  - During the braking process, kinetic energy is converted into heat. Brake fluid plays a crucial role in dissipating this heat to prevent the brakes from overheating. Overheating can lead to brake fade, a reduction in braking efficiency, and potential damage to braking components.

4. **Corrosion Prevention:**

  - Brake fluid acts as a hydraulic medium and also serves to lubricate and protect the various components of the brake system. It helps prevent corrosion within the brake lines, master cylinder, calipers, and wheel cylinders.

5. **Compatibility with Brake System Components:**

  - Brake fluid must be compatible with the materials used in the braking system, such as rubber seals and hoses. It should not cause deterioration or swelling of these components over time.

6. **Maintaining a Consistent Brake Feel:**

  - Brake fluid helps maintain a consistent and responsive feel at the brake pedal. This is important for the driver to have precise control over the braking force applied.

7. **Non-Compressibility:**

  - Brake fluid is designed to be non-compressible, ensuring an immediate and direct transfer of force from the brake pedal to the brake components. Compressibility would lead to a spongy or ineffective brake pedal feel.

It's important to note that brake fluid is hygroscopic, meaning it has a tendency to absorb moisture from the air over time. This moisture absorption can lead to a decrease in the boiling point of the brake fluid, which may result in brake fade under heavy braking conditions. Therefore, it's crucial to regularly check and replace brake fluid according to the manufacturer's recommendations to maintain the proper functioning of the braking system. Brake fluid replacement intervals are typically specified in the vehicle's maintenance schedule.