How to Check Brake Fluid
Updated: Aug. 27, 2019Make sure the corrosion inhibitor in your brake fluid hasn't worn out
Check your brake fluid condition
As with every other fluid in your car, brake fluid contains a main ingredient along with protective additives. The main ingredient in brake fluid doesn’t degrade, but the additives do. The most important additive is a corrosion inhibitor. The corrosion inhibitor prevents internal rusting of steel brake lines, calipers and ABS (antilock brake system) components. Once the inhibitors are exhausted, even minute amounts of moisture can cause dangerous and costly corrosion.
Plus: Learn what to do when your brake light comes on.
Most car manufacturers recommend a complete brake fluid flush every two years or 24,000 miles. Rather than rely on a general recommendation, you can test the actual condition of your brake fluid. To check your brake fluid, remove the cover of the master cylinder and dip a strip into the fluid. Shake off the excess fluid and wait 60 seconds before comparing the color of the strip with the guide on the brake fluid tester package. The guide tells you when it’s time to change the fluid. Find a package of 25 BrakeStrip test strips at brakebleeder.com.
Required Tools for this Project
You’ll need plastic gloves to check brake fluid.
Required Materials for this Project
Avoid last-minute shopping trips by having all your brake fluid tester materials ready ahead of time. Here’s a list.
- Brake fluid test kit