The purpose of brake fluid

The brake fluid is a liquid that is engineered to have a high boiling point, so that it doesn’t boil and turn in to vapors once the brake components heat up. Also it
doesn’t compress like gas does.
Vapor is gaseous and we know gas can be compressed, and that is not good for the brake system, because its behavior when used for the brake system can be unpredictable. For once the pedal will feel squishy and the next thing you know it suddenly expands causing the pistons of the brake calipers to suddenly shoot out and in turn locking your wheels.
This is why we don’t use water, since water can boil pretty easily.

Now how does it work?

Pascal’s law says that a liquid transfers the same amount of pressure applied to it towards all
directions, provided it is in an enclosed system. So that as you press on the brake pedal the same
amount of pressure is sent to the other end of the brake line.
But then there’s your brake booster before the ABS module then the brake lines. So your foot action is directly affecting your brake booster, and this booster
amplifies the pressure you applied so you can brake.

How does the brake system work.

It works by forcing the brake material into a rotating body (the rotor in the case of a disc brake) that is connected to the wheels. Once this brake material is pressed against the rotor it will convert the kinetic movement into heat by means of friction thereby stopping the wheels, stopping your car.
In the case of the disc brake, piston/s are used to force the brake material (brake pads) into contact with the rotor. This piston is being pushed by the brake fluid.

We use brake fluid because it is much easier to redirect compared to a cable. It is more reliable and
doesn’t break like a cable. But it is required that it is
cased in a sturdy material or lining. And the pressure
output can be easily manipulated, but that’s a
discussion for next time.

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