Checking Brake Fluid Is a Beginner Level Job for Most DIYers. Here’s Everything You Need to Know to Check Brake Fluid at Home.
- DIY Difficulty Level: Beginner
- Time Required: 10 minutes
- Tools & Materials:
What Is Checking Brake Fluid?
Just like other components in your vehicle, brakes need the correct amount of fluid to perform at their best. While many drivers regularly check their wiper fluid and their oil at regular intervals, brake fluid often gets overlooked. Brake fluid is a hydraulic fluid that helps the brake pedal move, provides lubrication to the braking system, and helps prevent corrosion.
Low brake fluid can reduce the effectiveness of your brakes. Another reason you want to check your brake fluid is because if it gets low, moisture can get in the reservoir and affect the performance. Keeping the brake fluid topped off helps prevent moisture from working its way into the reservoir.
Is It Safe To Drive Without Checking Your Brake Fluid?
Generally speaking, you should have the brake fluid whenever the brakes are serviced, and have the brake fluid inspected at least once a year. You can easily do this yourself by inspecting the fluid for the proper level and the proper color. If the fluid in the master cylinder reservoir is low or discolored, you should have this addressed immediately.
If the brake fluid is low, the brakes may still work because there is enough fluid in the reservoir. The fluid level could be low because the brake pads are worn and the caliper pistons are extended further out, but a low fluid level could also indicate a leak in the brake fluid system. If the fluid runs out or there’s an air bubble in the braking system, this could lead to reduced effectiveness of the brake pedal when it’s depressed. Checking your brake fluid is a relatively easy DIY job, so if you have some general knowledge of cars, you can easily do this job yourself to ensure your car is safe to drive.
When To Check the Brake Fluid
The brake fluid should be checked regularly. It’s a good idea to check it or have it checked every time you change the oil. At a minimum, you should check it at least once a year. Brake fluid can last for about five years before it needs changing, but it’s important to check the level at least once a year, if not more often. Keeping the brake fluid topped off and clean will ensure the car brakes will work correctly.
What Are Common Symptoms Indicating You Need To Check the Brake Fluid?
Some of the signs that you need to check the brake fluid include:
- Brake light on the dashboard illuminates
- Brake fluid looks dirty or discolored
- Brake feels spongy
- The car takes longer to stop than normal
Keep in Mind
As soon as you notice any of the signs that your brake fluid might be low or contaminated, you should have it checked or check it yourself. Driving with any indication of a faulty braking system could compromise your safety on the road. The color of the fluid is just as important as the level. Brake fluid should look almost clear with just a yellowish tint, and if it’s been dirty or contaminated, you should have the brake fluid flushed. Remember to always follow the manufacturer’s recommended maintenance schedule and do this service as advised for your make and model.
While you’re checking the fluid, it’s also a good idea to check the:
- Brake lines
- Brake pads
- Brake rotors
How To Check Brake Fluid
Here are steps you can take to check your car’s brake fluid:
Step 1: Find the Brake Master Cylinder Reservoir
Before you can check the brake fluid, you need to locate the master cylinder reservoir. It’s usually a plastic container mounted near the firewall at the back of the engine compartment. You can often find it on the driver’s side of the vehicle near the brake booster.
Step 2: Clean the Top of the Reservoir and Open It
It’s important to clean off any dirt or grime from the top of the reservoir before opening it. If any dirt gets into the fluid, it can cause the internal seals of the master cylinder to fail, and the brakes won’t work as effectively as they should. Once it’s clean, open the top of the reservoir by unscrewing the cap.
If you have an older vehicle, it might not have a plastic cap. Some have a spring-loaded clamp. You’ll need to pry the clamp to one side and then lift off the top in order to inspect the fluid level.
Step 3: Inspect the Fluid Level
Check to make sure that the brake fluid is at the recommended level. There should be a maximum fill line and a minimum to make this easy to check. If the fluid is below the maximum but not below the minimum, you can still drive, but more fluid should be added. If the fluid level is low, it’s time to have the brakes inspected by a professional. A drop in brake fluid often means the brake pads are worn to the point of needing a replacement.
Step 4: Inspect the Fluid Color
The color of the fluid is also important. It should be clear and yellowish. Old brake fluid will look muddy and black, almost like the color of old engine oil. Just like engine oil, brake fluid gets darker as it collects debris, and this makes it less effective.
Step 5: Schedule Brake Service if Needed
If you determine that the brake fluid is low, it could just need more, but it may also be a sign that you need brake service. If the reservoir is empty, it’s time to call a mechanic and have them check the braking system. The fluid might need to be completely replaced, and you may have to have them bleed the brake system.
Still Need Help?
Want an expert mechanic on speed dial who can walk you through DIY repairs and answer any questions? Join FIXD Mechanic Hotline for unlimited access to our Master Mechanics Monday-Friday, 8 a.m.-8 p.m.
Disclaimer: The guidelines in this article are general and not meant to replace instructions for your specific vehicle. Please consult your owner’s manual, repair guide, or a professional before attempting repairs.

At FIXD, our mission is to make car ownership as simple, easy, and affordable as possible. Our research team utilizes the latest automotive data and insights to create tools and resources that help drivers get peace of mind and save money over the life of their car.