Brake fluid is a hygroscopic fluid that works within a closed system in your vehicle. When you press down on the pedal, the fluid transfers pressure that ends up bringing the vehicle to a stop.

How Brake Fluid Works


Why It Needs to Be Changed

Brake Fluid is Hygroscopic, which is a huge word that means it loves water. If water is around, brake fluid will absorb it. But the more water it absorbs, the less strength it has. This is why brake fluid exists in a closed system in your car. Most brake fluid will absorb about 2% water over the course of a few years, and that creates a major decrease in the amount of heat and cold that fluid can withstand. This is why it's important to change your brake fluid regularly.


Brake Lines Are Important

The brake lines allow your brake system to respond to your braking in one closed system. When you press down on the brake pedal, the fluid transfers pressure to the brake calipers which presses the pads against the brake rotor disc and/or wheel cylinders that push the brake shoes against the inside of the brake drum, which stops the vehicle. If there's a leak in the brake line, or if you have low levels of brake fluid, you'll get less or no pressure from the pedal. This, of course, can be extremely dangerous. Brake lines also keep water away from your brake fluid, some are even made from gore-tex composite materials for this purpose.

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