A fundamental condition for safe driving is that the car’s braking system always works properly. Many people regularly change the oil or check the tires, but brake fluid often falls to the wayside — yet it is just as important as any other component or lubricant.

This article helps you understand why the condition of brake fluid matters, when it should be checked or replaced, and what to watch out for during the process.

What Is Brake Fluid, and What Does It Do?

Brake fluid is the “power” of the hydraulic braking system. When you press the brake pedal, the force is not applied directly to the brake pads but is transmitted through this fluid to the wheels. That’s why it’s critical always to have the right amount and quality of brake fluid in the system — if this is neglected, safety risks may emerge even in the short term.

One of the properties of brake fluid is that it tends to absorb water from the air. This lowers its boiling point, and in extreme cases can even make the brake pedal “sink” — i.e. depress with no braking effect, which is extremely dangerous.

When Should You Replace or Check It?

Most car manufacturers recommend replacing brake fluid every 2 years or after about 40,000–60,000 km. The reason is that moisture gradually degrades performance, even when everything seems fine from the outside.
These signs may indicate trouble:
•    the brake pedal feels “spongy”
•    longer braking distance
•    dark, contaminated fluid in the reservoir
Of course, some motorists might not pay special attention to this, but there’s no need to panic. The key is that once problems start to look serious, definitely consult a professional.

Step by Step Brake Fluid Check
•    Park the car on a level surface, engage the parking brake, and wait for the engine to cool.
•    Open the hood — the brake fluid reservoir is usually on the passenger side, near the windshield.
•    Check that the fluid level is between the MIN and MAX marks.
•    Observe the fluid’s color: ideal is a light amber. If it’s dark brown or black, time for a change. Don’t dismiss it as merely an aesthetic issue — it’s important.
•    If you have a brake fluid tester handy, it gives an even more precise reading of water content.

Replacement — At Home or at a Workshop?

Changing brake fluid is not the easiest job, but it can be done at home with some mechanical sense. Still, if you're uncertain, better leave it to a professional — a faulty replacement can even shut down the braking system. The most important thing is to know your own limits and to assess exactly what tools and conditions you need. It’s worth mentioning that in the current economic climate, many choose to do it themselves, which is supported by the availability of tools and guides.
The process in brief:
•    Drain the old fluid from the bleed valves on all four calipers
•    Fill new brake fluid into the reservoir
•    Bleed until clean, bubble free fluid flows
•    Constantly top up to avoid drawing air into the system
•    It’s helpful to have assistance, but vacuum brake bleeders also exist, allowing a single person to do the job.

Waste Management

Used brake fluid is classified as hazardous waste because it contains toxic substances and can easily contaminate soil or water sources. Therefore, it must never be poured into drains, spilled on the ground, or treated as household waste. The safest approach is to collect the drained fluid in a sealable plastic container, then bring it to a petrol station, a professional garage, or a waste disposal yard that accepts hazardous materials. If you're unsure where to take the used fluid, check your local waste management website or ask your municipality. Proper disposal is not only environmentally responsible but also a legal obligation, as improper handling may incur fines.

Summary

Maintaining brake fluid requires little effort but can make a big difference in safety. Although it may not be visible externally, the condition of the fluid decisively affects the braking system’s performance, especially in emergencies or during prolonged braking.

It’s worth checking the fluid level and condition at least once a year, and doing a full replacement every two years — whether at a workshop or at home with proper tools. If you do it yourself, always ensure no air enters the system and use the brake fluid type specified by the manufacturer (e.g. DOT 4).

Remember: the braking system is the life insurance of your car, and it’s not worth cutting corners. A well maintained system safeguards not only you, but also your passengers and other road users.