To top up the brake fluid or eliminate the cause of its leakage, contact a BMW service station where the grades of brake fluids (DOT 4) suitable for your car are known.
Please note: Brake fluid is hygroscopic, meaning it will absorb moisture from the air over time.
To ensure the operational reliability of the brake system, it is necessary to visit a BMW service station every two years to replace the brake fluid.
Brake fluid is poisonous and corrodes the car's paintwork. Therefore, it should be stored only in closed original packaging and in places inaccessible to children.
When replacing brake fluid, follow the rules for disposal of toxic substances.
Warning: Do not spill brake fluid. Fill the reservoir only up to the "Max" mark. If the brake fluid comes into contact with hot engine parts, it may ignite. Risk of burns!
[The original article is posted on the resource «BMWMAN»]