What Should I Do If My Brake Fluid Looks Cloudy?

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The brake system is a vital component of any vehicle. It ensures that you can slow down or stop your car when needed. Central to this system is the brake fluid, a hydraulic fluid that transfers force from the brake pedal to the brake calipers to clamp onto the rotors. But what should you do if you notice that your brake fluid appears cloudy or discolored? Here's a breakdown of what this might mean and the steps you should take.

Why Brake Fluid Might Look Cloudy

  1. Water Contamination:
    • Origin of Water: Humidity in the air, environmental changes, or even condensation within the brake system can lead to water contamination. This moisture will eventually find its way into the brake fluid.
    • Impact: Apart from making the fluid cloudy, water-contaminated brake fluid can boil during intense braking, creating vapor bubbles that significantly reduce braking efficiency. Moreover, water in the brake fluid can also cause rusting of internal brake components.
  2. Air Entrapment:
    • How Air Enters: Air can infiltrate the brake system during maintenance, especially if the system isn't properly bled. Also, worn-out seals or microscopic cracks can admit air over time.
    • Impact: Air bubbles in the brake system can compress, unlike the brake fluid, leading to a spongy brake pedal feel and reduced braking power.
  3. Old Brake Fluid:
    • Degradation Over Time: As brake fluid ages, its chemical properties change. This can result in decreased performance, increased acidity, and greater susceptibility to water absorption.
    • Impact: Degraded brake fluid can harm the internal components of the braking system, leading to costly repairs in the future.
  4. Contamination with Other Fluids:
    • Common Mix-ups: At times, brake fluid reservoirs and containers can resemble those of other automotive fluids. This can lead to unintentional mixing.
    • Impact: Mixing brake fluid with other substances can lead to unpredictable chemical reactions, severely compromising the integrity and functionality of the brake fluid.

What To Do

  1. Check the Brake Fluid Regularly:
    • Routine Inspections: Every time you pop the hood for an oil change or any other maintenance, take a quick glance at the brake fluid reservoir.
    • Signs to Look Out For: Besides cloudiness, also look for a darkened color or any particles floating in the fluid.
  2. Flush and Replace:
    • Frequency: While most manufacturers recommend changing brake fluid every 1-2 years, it's essential to refer to your specific vehicle's manual.
    • Procedure: Flushing involves removing the old fluid and any contaminants from the brake system and replacing it with fresh fluid.
  3. Inspect for Leaks:
    • Regular Maintenance: Always keep an eye out for wet or oily patches near the wheels or brake lines.
    • Potential Leak Points: Common areas include brake line connections, caliper seals, and the master cylinder.
  4. Avoid Cross-Contamination:
    • Storage: Store brake fluid in its original container, clearly labeled, and away from other automotive fluids.
    • Application: When adding brake fluid, ensure that funnels or tools used are clean and were not previously used for other fluids.


It's essential to remember that the brake system is one of the most critical safety components of your vehicle. As such, regular checks and maintenance, especially concerning the brake fluid's quality, can ensure both your safety and that of other road users.


Q: How often should I check my brake fluid?
A: Ideally, check it at least twice a year.

Q: Can I replace the brake fluid myself?
A: If you're confident and have the necessary tools, you can. However, if unsure, it's best to consult a professional.

Q: Does brake fluid have an expiration date?
A: While brake fluid doesn't typically come with a strict expiration date, it's recommended to replace it every 1-2 years or as specified in your vehicle's manual.

Q: What happens if I ignore cloudy brake fluid?
A: Ignoring it can lead to decreased braking performance, corrosion of brake components, and potential brake failure.