Most car manufacturers recommend changing brake fluid every 2-3 years, or every 40,000-45,000 miles. Even if it looks clear, you need to change it because brake fluid absorbs water from the air into the fluid. This moisture will still shorten the performance and safety of the brakes.
Why Should I Change Brake Fluid?
Brake fluid is hygroscopic, meaning it pulls moisture from the air. This moisture will reduce the boiling point of the brake fluid, & this leads to a “spongy” brake pedal or even a brake failure under heavy use.
Water contamination can also cause corrosion to any of the automobile’s brake system components, such as the master cylinder, brake lines, and calipers.
What Happens if You Don’t Change Brake Fluid?
Not changing brake fluid ultimately can lead to corrosion or complete brake failure. Here are a few things you’ll notice:
- Soft or spongy feel on the brake pedal due to vapor bubble formation in the fluid when it boils.
- Reduced braking performance. Worth considering when going down a steep hill or during a sudden stop.
- Possible corrosion and rust damage, which can become very pricey or worse, lead to brake failures.
- ABS and other systems can fail to function as intended because dirty brake fluid can impact how the sensors operate.
A Reddit user shares their experience with humid climates and recommends changing brake fluid more often.
“As it absorbs more moisture, it boils at a lower temperature and can cause brake fade or other components to stick or bind,” writes the user. “Brake fluid also lubricates all the internal ABS components.
How Often to Change Brake Fluid as per Manufacturers
| Manufacturer/Source | When to Change? |
| Toyota | Every 2 years or 20,000 miles |
| Honda | Every 3 years |
| Jiffy Lube | Every 2-3 years or 45,000 miles |
| Haynes | Every 2 years, regardless of mileage |
| General Industry | Every 2-3 years or 40,000 to 45,000 miles |
Also Read: How Often Should I Change My Oil
Signs Your Brake Fluid Needs Attention
Your car tells you if your brake fluid replacement is due. You just have to pay attention!
These are the signs you should look out for:
- Soft or sunken feel on the brake pedal
- The brake light on the dashboard or ABS light illuminates
- Fluids, dark or murky-looking, & normal fluid should look clear or light amber
- Weird squealing, grinding, or vibrations when braking
- Reduced performance or delayed response in the overall braking performance
How Much Does Brake Fluid Replacement Cost?
Brake fluid replacement is usually a low-cost item, with fluid costing anywhere from $10-15 per liter, with the typical car requiring 1-2 liters.
Labor can run anywhere from $50 to $150, depending on the place of service. Dealerships tend to charge more than a local garage.
You could potentially do it yourself if you have the proper tools and mechanical knowledge.
How to Change Brake Fluid: A Quick Overview
- From the master cylinder reservoir, extract the old brake fluid.
- Fill the master cylinder reservoir with new brake fluid recommended by the manufacturer.
- Flush the brake calipers & wheel cylinders by bleeding the brakes & ensuring that there are no air bubbles in the brake lines.
- Check on the levels of fluid & top-off as needed.
- Dispose of your old brake fluid properly.
Can You Mix Old and New Brake Fluid?
You could, but I don’t recommend it!
If the old brake fluid contains moisture or contaminants, it limits the newly blended fluid’s performance. It is better to flush & replace all the brake fluid.
Is a Brake Fluid Flush Necessary?
Yes. A brake fluid flush exchanges the old & contaminated fluid with the new fluid, which maintains brake system performance & helps prolong the life of the brake parts.
Frequently Asked Questions
Do people actually replace brake fluid?
Yes, changing the brake fluid is part of recommended maintenance to make sure your brakes are safe & effective.
Can old brake fluid damage my car?
Old brake fluid will have moisture that can corrode and destroy parts of your brake system over time.
Is a brake fluid change expensive?
Overall, it is a reasonably low-cost service compared to other brake repairs costing $10-15 per liter.
How long can you drive without changing brake fluid?
Three years or 45,000 miles is long enough without changing; brake fluid does degrade.
Does brake fluid affect ABS?
Yes, old brake fluid can allow contaminants in, & these contaminants will degrade the ABS sensor’s performance, eventually affecting braking performance.
Final Say
While brake fluid might not be the first thing you think of when considering your vehicle’s safety, it has a more important function than you might think. Brake fluid is necessary to keep your vehicle’s brakes fresh & safe.
Although a brake fluid change may feel like another maintenance headache, think of it as an extremely cheap insurance policy against expensive and dangerous brake failure. A little peace of mind on the road is worth the effort.
