Brake fluid operates in a high-pressure, high-temperature environment – 100 to 200° F on a typical drive and as high as 550° F when you travel downhill. To handle these conditions, brake fluid has a high boiling point but this solution also attracts moisture from your surroundings. The introduction of water lowers the fluid’s boiling point and in turn, brake components start to corrode and brake failure could result.
Before your brake system enters this perilous state, make sure you change your car’s fluid. What should you know?
Signs It’s Time for a Change or Flush
Your car might be trying to tell you the brake system needs new fluid if:
- You have to press down on the brake pedal nearly or completely all the way.
- When you do press, the brake pedal has a “spongy” – rather than secure – sensation.
- You pump your pedals at least twice to get the car to fully stop.
- Your brake light recently came on.
Unlike with your car’s other fluids, brake fluid doesn’t get dirty or evaporate. When moisture lowers its boiling temperature, its effectiveness does begin to decline. Contaminating your car’s fluid is only the beginning:
- Air: Exposing the fluid to air causes it to oxidize, which also lowers its boiling point.
- Cold Weather: Once moisture is in your brake fluid, the lower boiling point is just one issue. In winter, these water droplets create ice crystals in the fluid and make it harder to break.
- Rusting: The longer you avoid changing contaminated fluid, the greater the chances of rusting parts. The fluid may also take on an acidic quality, which scrapes away at your wheel and master cylinders, calipers, the brakes themselves and other key parts of a car’s ABS.
When to Change Your Brake Fluid
As a general guideline, make an effort to get your brake fluid topped off by a professional every two years. Much like the rest of your car’s fluids, manufacturers have different guidelines for their models, varying from as little as 20,000 miles for a Mercedes-Benz to 45,000 for a Chevrolet. Others recommend every three years, regardless of mileage, and some brands don’t include a timetable in the owner’s manual.
In any case, it’s a good idea to have someone inspect the fluid for its water content at least every two years. Never let more than five years go by between changes. If you live in a region with high-humidity weather or snowy winters, you might need to schedule more frequent changes. In these cases, your brake fluid has a greater chance of getting contaminated with moisture, salt or other fine particles.
Types of Brake Fluid
Do you know which type of fluid your car needs for the next change or flush? Most personal vehicles take a DOT 3 or DOT 4 fluid but in certain cases, DOT 5 may be needed.
What’s the difference? The number indicates the fluid’s viscosity and boiling point. While DOT 3 and 4 are glycol-based solutions, DOT 5 is silicone based. Considered an upgrade over the previous two, DOT 5 won’t eat away at your car’s paint or absorb water. This last point creates a new set of issues: Instead of getting absorbed by the fluid, water may pool in your brake system directly and result in corrosion.
Have you gotten to that two-year mark? Have DaSilva’s experienced team examine and change your car’s brake fluid. To learn more, contact our Naugatuck shop!