Brake fluid is the working liquid that carries force from a vehicle’s brake pedal to its brakes. When a driver presses the pedal, fluid pressure moves components at the wheels, helping brake pads or shoes slow the vehicle. That job requires more than simply filling a reservoir: the fluid must resist heat, protect internal parts, and work with the vehicle’s seals and braking components. Understanding what brake fluid is used for helps explain why the correct type and condition matter for safe, reliable braking.
- Brake fluid carries hydraulic pressure from the master cylinder to calipers or wheel cylinders, allowing the brakes to apply.
- It must resist heat, protect compatible components, and remain suitable for the vehicle’s seals and system design.
- Moisture can lower the boiling point of glycol-based fluid, which is why service schedules and fluid condition matter.
- DOT 5 is silicone-based; DOT 3, DOT 4, and DOT 5.1 are glycol-based. Similar labels do not mean all types can be mixed.
- The owner’s manual and manufacturer specifications determine the correct fluid and maintenance procedure.