Brakes are arguably your car’s most important safety feature. But they’re only as effective as the fluid that makes them work. Luckily, you don’t need to be a professional mechanic to check your brake fluid regularly. You can do it yourself in just a few minutes–no tools required! Here’s how to do it:
1. Open the reservoir
Your brake fluid reservoir is attached to the brake master cylinder, which on most vehicles looks like a small metal block with a dark-colored cap. Before you open the cap, wipe it with a clean towel or lint-free cloth to prevent dirt or debris from getting into your brake fluid.
Using your fingers, open the brake fluid reservoir and remove the cap. Look at the brake fluid level, which should be marked with a minimum and maximum line. If the fluid is below the minimum, add brake fluid until it reaches the maximum line.
Avoid overfilling, as excess brake fluid can cause problems. It is also recommended that you use only the type of brake fluid recommended by your owner’s manual, such as DOT 3 or DOT 4.
2. Check the level
Brake fluid is essential to your vehicle’s braking system. However, like any fluid, it can get low. Luckily, it’s easy to check the level of brake fluid on most vehicles. First, locate the master cylinder reservoir which is usually a simple plastic container on the driver’s side of the engine bay. The reservoir will have markings that indicate the minimum and maximum levels for brake fluid.
If the brake fluid is below the minimum line, you should add some. Also, if the brake fluid looks darker brown or black, it’s time to change it. The color changes when the fluid gets old or contaminated. It should be clear to light yellow.
3. Check the color
Brake fluid transfers force to your brakes when you step on the pedal, creating friction between brake pads or shoes and rotors or drums. It’s a non-compressible hydraulic fluid that operates under high pressure and temperatures.
New or freshly poured brake fluid is typically clear with a yellow tint. However, it can darken over time due to the additives wearing out. Dark fluid can also indicate contamination that requires a flush.
Glycol-ether (DOT 3, 4, 5.1) and silicone brake fluids are both hygroscopic, meaning they can absorb water from the atmosphere. These types of brake fluids should not be mixed as they are incompatible with each other. Changing your brake fluid is a simple DIY maintenance item.
4. Check the pressure
Brake fluid works at very high pressures, and needs to operate perfectly to ensure proper braking performance. Over time, it can degrade or lose its ability to perform as expected.
A spongy brake pedal is an indicator of low pressure, but it may also indicate other problems. You can check the level of your brake fluid by opening the reservoir, and then comparing it to the mark on the reservoir that indicates the maximum fill amount.
Glycol-ether (DOT 3, 4, and 5.1) brake fluids are hygroscopic, and will absorb moisture from the air. This moisture can affect the boiling point, and can corrode seals on the master cylinder and pushrod.
5. Check the seals
Brake fluid is not just a lubricant for moving parts, it also protects them against corrosion. To do this, it has to withstand high temperatures. But if the fluid is too hot, it can cause the seals to break down.
The best way to prevent this is to use a high-quality brake fluid with a DOT rating. This will ensure that the fluid can withstand high temperatures without boiling. It’s also a good idea to keep the reservoir closed as much as possible, so that it doesn’t come into contact with excessive air and moisture. This will help extend the lifespan of the seals and gaskets. Also, it will prevent the fluid from absorbing moisture and becoming cloudy.
6. Check the temperature
Brake fluid transfers movement and force when you press down on the brake pedal. It is also a lubricant to prevent corrosion on movable parts. It must remain fluid in all temperatures.
All glycol-ether (DOT 3, 4, and 5.1) brake fluids are hygroscopic, meaning they absorb moisture from the atmosphere. This lowers the boiling point of the fluid, which can cause premature brake failure.
A conductivity meter will not correctly test the boiling point of a brake fluid, as they are not calibrated for all types of fluid. The only accurate method is with a refractometer. Using this method, you can determine the water content and estimate the boiling point of your brake fluid.
7. Check the pressure gauge
Whether you’re adding fresh fluid or merely observing the level, having a pressure gauge in your garage is an easy way to monitor your brakes. A quick check of the pressure can help identify a potential problem and save you from a costly repair in the future.
Brake fluid is a type of hydraulic fluid that helps transmit force into pressure in a vehicle’s braking system, bringing it to a stop. The fluid must operate at high temperatures and pressures, which is why it’s so important to have it flushed or replaced regularly. A well-functioning brake system is essential to safe driving, so pay attention to odd noises or a hard pedal that may signal problems with your brake fluid.
8. Check the leaks
Whether the fluid is leaking from the reservoir or other components, it’s important to have this checked out by a professional. This will prevent the system from overheating, which can damage or destroy the brake pads and rotors.
The brake fluid reservoir usually has a gauge that shows the appropriate level, and there are markings that indicate when it’s time to add more. It’s also a good idea to check the brake fluid often and according to your vehicle’s recommended maintenance schedule, which can be found in the owner’s manual.
Regularly checking your brake fluid is a simple but essential part of vehicle maintenance. By monitoring the level, colour, temperature, and potential leaks, you can keep your braking system performing safely and efficiently. A few minutes of inspection can prevent costly repairs and ensure your car stops reliably when you need it most.
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