Some carmakers recommend replacing brake fluid every two years or 24,000 miles. Others don’t mention it at all. But it’s easy to test your brake fluid. Just dip a test strip into the fluid and compare the color to the chart on the packaging.
You can’t do a complete brake fluid flush yourself, but you can do the next best thing—a fluid swap. This procedure won’t replace all the old fluid with fresh, but you’ll introduce enough new fluid to make a difference.
Use a baster to suck out the dark brown brake fluid (brake and power steering fluids are incompatible, so use a different baster for each). Squirt it into a recycling bottle. Refill the reservoir with fresh brake fluid as shown. Then drive the vehicle for a week to mix the new fluid with the old. Repeat the procedure several times over the next few weeks until the fluid in the reservoir retains its light honey color.
Note: The brake fluid may damage the baster’s rubber bulb, so don’t suck the fluid all the way into the bulb.