Brake fluid is not an oil as it is wrongly said.
It is instead a special liquid that has a particular characteristic, it is hygroscopic, it absorbs humidity.
When this happens it can create serious problems with the braking system.
It is therefore very important to replace it within the times indicated by the vehicle manufacturer. Usually every four years.
This operation, however, let it be performed by a professional mechanic given the delicacy of the intervention.
Check the brake fluid level
You can check the brake fluid level by looking at the indication notches on the reservoir in the engine compartment.
This may decrease slightly over time in relation to the wear of the brake caliper pads.
If we notice a sharp drop or the warning light on the dashboard comes on, a professional mechanic will be required.