How To Check and Change Your Vehicle’s Brake Fluid

Our vehicles are vital to our daily lives, so we need to practice diligent car care to keep them running at peak performance. A well-maintained vehicle is integral to staying safe on the road .

Our brakes are one of the most significant ways our vehicles keep us safe. We use our brakes every single time we drive, and Street Directory estimates that U.S. drivers engage their brakes 75,000 times a year. Brakes need routine maintenance to function well. Driving with low brake fluid is dangerous, as it affects your vehicle's ability to stop.

Whether you do it yourself or take your car in for a brake fluid service, checking and changing your vehicle's brake fluid is essential for safety. Below, we've compiled a step-by-step plan for checking and changing your brake fluid—whether you're a new driver or a seasoned veteran.

Step 1: Locate the Brake Fluid Reservoir

Pop your vehicle's hood (you can find the lever on the driver's side) and thoroughly secure it. The hood of your car may have a safety catch that you’ll need to release in order to fully lift the hood. Most vehicles have a hood prop, which is a thin metal rod located inside the hood of the vehicle that you can use to keep the hood from falling down.

Brake fluid reservoirs are in different places under the hood, depending on your vehicle's make and model, but you will typically find it near the master cylinder. The master cylinder is a major component of your car’s brake system and is usually mounted on the opposite side of the brake pedal. Older vehicles may have a metal, box-like reservoir, while newer reservoirs usually look like hard plastic containers.

If you can't find your brake fluid reservoir, consult your owner's manual to help locate it. You can also search online for an image of your vehicle's make and model of brake reservoir by typing in a search term like "2017 Toyota Camry brake fluid reservoir."

Step 2: Check Brake Fluid Level, Color, and Clarity

Once you locate the brake fluid reservoir, you can check the brake fluid level.

Open the reservoir by either unscrewing the cap or using a screwdriver to pry the clamp off. Thoroughly wipe off the top of the reservoir to keep any accumulated dirt from getting into your brake lines.

The method you use for checking your car's brake fluid levels depends on which reservoir you have. An older vehicle with a metal reservoir will have a "full" line inside once you open it. A newer vehicle with a plastic reservoir will have "min" and "max" lines on the container's exterior for easier accessibility. If the level is under the minimum line, then you need to add fluid. For older vehicles, you’ll need to remove the typical spring-loaded cap (a screwdriver can be a good tool for removing the cap) in order to see the lines designating the reservoir as “full.”

Your brake fluid level isn't the only thing you need to check. The color and clarity of the brake fluid can also give you valuable insights.

Eyeball the color of the brake fluid to determine if it needs to be changed. If it's clear with a yellowish tint, it's still fresh and in good shape. Over time, dirt and contaminants get into a car's brake fluid and make it look darker. If the fluid is dark brown or black, similar to the color of motor oil, it's time for a brake fluid change. Your vehicle's brake fluid will also likely need to be tested by a mechanic for copper levels. Brake fluid needs to be replaced when copper levels reach 200 ppm (parts per million).

Step 3: Refill Brake Fluid Level to the “Full” Line

If you're refilling your vehicle's brake fluid yourself, take care to purchase the same type of fluid already in your reservoir. If you aren’t sure what kind of brake fluid your vehicle uses, consult your owner’s manual or check the cap on the master cylinder reservoir. The most common types of brake fluid are DOT 3 and DOT 4. (There is also a DOT 5, but this is primarily used for cars that get stored for long periods of time.) Brake fluid can be purchased from most auto parts stores.

For older vehicles: With the reservoir open, carefully pour in the new brake fluid into the reservoir until the level reaches right under the "full" line. Pour slowly so you don't end up overfilling it.

For newer vehicles: Open the reservoir and pour the brake fluid while watching the level on the outside of the container. If your car has a dual chamber, fill them to just under the "max" line.

If your brake fluid levels have dropped quickly or excessively, this is a sign your brake pads are worn and need replacing. You can either do this yourself or take your vehicle to a mechanic as soon as possible. Worn brake pads can decrease your car's response time. They can also damage your rotors and calipers, which means a more costly repair bill.

How often you should get your brake fluid changed depends on the type and age of your vehicle. Plan to get a full brake fluid flush roughly every two years or 20,000 miles—whichever comes first.

Step 4: Replace the Brake Fluid Reservoir Cap and Clean Up

Be diligent about keeping dust and dirt from the engine compartment out of your reservoir, as even a small amount of debris can affect your car's performance. Use a clean, lint-free rag to wipe off the entire reservoir cap before replacing it.

Brake fluid is extremely toxic and corrosive. Wash your hands after checking your brake fluid, and exercise caution to keep from getting it on your clothes. Brake fluid also damages paint, so make sure you don't spill any on your vehicle's exterior.

Brake Fluid Frequently Asked Questions

Tending to your car's brakes is an essential part of car maintenance. Drivers typically have a lot of questions about how, when, and why they should check their brake fluid levels and perform (or schedule) maintenance. Here are answers to some of the most common questions.

How do I know if my brake fluid level is low?

There are three major signs that your brake fluid could be low:

Your brake warning light comes on your vehicle's dashboard.
Your brakes feel spongy when you push them. The spongy feeling comes from air that has crept into your brake lines.
Your brakes aren't as responsive as they used to be.

How often should I check my brake fluid?

Proactively monitoring your brake levels can save you from dealing with bigger problems (and safety issues) later on. An easy way to remember to check your brake fluid is to do it every time you have an oil change. Make sure you check it at least once a year to avoid dealing with serious issues like avoidable accidents and expensive repair costs. Remember to check your brake fluid immediately if the brake light on your dashboard illuminates.

Do you check brake fluid with the car running?

You will get the most accurate reading by checking your brake fluid when your vehicle is off, and its engine is cold. First thing in the morning is a great time to check it, as it gives your car several hours to sit.

What happens if I don’t have enough brake fluid?

Low brake fluid can decrease your overall brake performance, which means that you may have trouble stopping as quickly as you need to. Your brake pedal may also feel mushy when your brake fluid is low due to the air that gets into your brake lines, as mentioned above.

What if my car has an anti-lock braking system (ABS)?

The ABS has been around for a few decades now. Cars made in 2013 or after are equipped with anti-lock brakes, which are different from a traditional braking system. Before checking your ABS fluids, consult your owner's manual for instructions. Anti-lock brakes sometimes require you to pump your brake pedal 25 to 30 times before opening and inspecting the fluid levels.

Schedule service at a local service center near you if you don't feel comfortable checking your own brake fluid. A qualified mechanic can check it for you and advise you whether you need fluid added or a complete line flush.

Safe Drivers Choose Clearcover for Auto Insurance

Working brakes are one of the most critical parts of safe driving. Whether you choose to DIY or go to your favorite mechanic, scheduling regular maintenance keeps your brake fluid at an optimal level, which keeps your car running smoothly.

Keep in mind that it's also essential to be a perceptive driver. Watch for your brake light to come on, notice changes in how your brake pedal feels, and be aware of how quickly your vehicle stops. Don't ignore these potential warning signs—they may indicate a significant issue that could cause a serious car accident.

Some aspects of car ownership can be stressful, but at Clearcover, we believe that car insurance doesn't have to be. Our award-winning app is easy to use, our claims process is lightning-fast, our honest, transparent policies speak for themselves, AND we’re affordable. Take control of your coverage and get a free, no-obligation quote today.