Brake fluid change – when and why is it important?

Contents

• Main characteristics of good brake fluid
• DOT 3 vs DOT 4
• Recommended replacement interval
• Symptoms of brake fluid problems

One of the most important, yet often underestimated, tasks in vehicle maintenance is regularly changing the brake fluid. It is vital for the functioning of the entire braking system, including the ABS module, and plays a key role in ensuring reliable braking under all conditions. However, many drivers are not aware of when this procedure should be carried out and what risks neglecting it entails.

Main characteristics of good brake fluid

The fluid in the vehicle's braking system transmits force from the pedal to the brake units. It must remain stable and not change under the influence of temperature and pressure. For this purpose it needs a high boiling point, resistance to oxidation and chemical stability.

DOT 3 vs DOT 4

One of the most frequent questions we encounter at the OnDrive car service is which of these two options is better. DOT 3 is cheaper and used in older vehicles, while DOT 4 has a higher boiling point and is suitable for modern vehicles, especially those with ABS and ESP systems.

Recommended replacement interval

Manufacturers recommend changing it every 2 years or 40,000 km. This may vary depending on your car model and driving style. But at each change it is advisable to perform a complete flush of the braking system to avoid mixing old and new fluid, which would reduce its effectiveness.

Symptoms of brake fluid problems

Regardless of when you last changed the brake fluid and which type you chose, if you notice the following symptoms you should have your car checked and serviced as soon as possible:

• soft or „sinking“ pedal – if the pedal sinks too easily or does not provide the usual resistance, this may be a sign of moisture or air in the hoses;

• reduced braking efficiency – delayed braking or an extended stopping distance are direct results of reduced fluid effectiveness;

• uneven ABS operation – any absorption of moisture or contamination of the fluid negatively affects the ABS, causing uneven braking and potentially creating a road hazard.

If you notice leaks or stains under the vehicle, it is also advisable to turn to a certified service for inspection, diagnosis and timely repair.

Whether you drive a new car or an older model, brake fluid is essential for your safety. Regular replacement not only ensures efficiency but also long-term protection of the entire braking system. In addition, it helps you avoid potential road hazards, especially in situations where sudden braking is required.