To drive, it is vital to be able to brake. This will prevent accidents for you and other road users. For modern vehicles, the brake is hydraulically operated. The word hydraulic refers to a fluid. In the case of a hydraulic brake, the fluid is a liquid: the brake fluid.
Hydraulic brake operation
The operation of a hydraulic braking system is simple. It is composed of:
- an emitting cylinder, containing a piston, filled with the liquid. This piston is in contact with the brake pedal.
- a receiving cylinder, also containing a piston, but empty at rest. This piston is placed against the brake shoes.
- a pipe, also filled with brake fluid.
The action of your foot on the pedal pushes the piston of the transmitter. By moving the liquid from the transmitter to the receiver, the latter's piston actuates the brake shoes and involves braking. By releasing the pressure on your brake, a spring restores the shoes to their original state. This revives the receiver and causes the brake fluid to move around in the transmitter.
The importance of the brake fluid is particularly highlighted. It must be noted that it is the basis for the operation of the hydraulic brake.
Choosing the right brake fluid
Given the importance of brake fluid, it is essential to choose it carefully. These are some of the properties of brake fluid that will help you make the right choice.
- Its incompressibility:
For the transmitter thrust to be received in the receiver, the fluid must act as a solid, non-compressible rod.
- Its water content:
If its water content is high, it is more likely to boil quickly. Air will then be born in the system.
It is best to choose a brake fluid with low compressibility and water content.
When to change the brake fluid
Brake fluid is a chemical product. It oxidizes and degenerates systematically over time. After 18 months, it is recommended to have it changed. But if before that time you notice that the fluid turns black or dark brown, it is better to replace it immediately. A poor condition of the brake fluid, or even a poor quality, can lead to a malfunction of your brake. Damage to cylinders and pistons is also not excluded.