To keep your car running, it’s necessary to pull into the gas station every few hundred miles for a fill-up. You don’t think about it. You just do it.
Unfortunately, other car maintenance routines aren’t as automatic. You may fill up your windshield washer fluid when it’s empty because your vision becomes impaired through the dirt on the windshield. You may pull in for an oil change because the sticker on your window gives you a date and mileage number to shoot for.
But what about brake fluid?
What does brake fluid does for your car?
Brake fluid is also known as hydraulic fluid. Brake fluid allows the various components of your car’s brake system to move and operate efficiently. Without brake fluid, your vehicle wouldn’t come to a stop when you pushed down on the brake pedal.
Brake fluid is designed to operate under high temperature and high pressure. It’s a non-compressible fluid that is housed within the brake lines, and is delivered to the various braking components when you press down on the pedals. It’s brake fluid that helps apply pressure to all four wheels, bringing your car to a stop. It works like this:
- When you want to stop or slow down, you press down on the brake pedal.
- The pedal starts the braking process by compressing a piston that resides in each brake caliper.
- This process increases the pressure within the brake line, sending brake fluid where it needs to go throughout the brake system.
- Brake fluid causes the rotors to connect with the brake pads, which in turn makes contact with the wheels. This friction slows the rotation of the wheel, eventually bringing it to a stop.
Without brake fluid, your brake system wouldn’t work. If brake fluid runs low, is contaminated with dirt or grime, or doesn’t flow properly in any way, your braking system is compromised.
That would make your brake fluid pretty important, right? Yet it’s one of the most forgotten fluids in your vehicle.
What happens to brake fluid as it ages?
Brake fluid doesn’t exist in a perfectly sterile world. Over time, it absorbs moisture, which has the potential to lower the boiling point and raise the freezing point. Dirt infiltrates the fluid, increasing the possibility of corrosion throughout the braking system components.
This is a slower process than the motor oil you change out of your vehicle several times per year. But like any car fluid, your brake fluid has to be at optimal performance level for it to do its job correctly. Because brake fluid is an integral part of your car’s safety, check your owner’s manual to determine the recommended brake fluid changing schedule. If you think you might have a problem with your brake fluid, have one of our mechanics check it out to ensure your safety.
How do you check brake fluid?
When you open up the hood on your car, you’ll find brake fluid is usually stored in a translucent plastic container. You should be able to see the levels of brake fluid without removing the cap. This is different than other fluids where you can remove the cap and check levels with a dipstick, like your motor oil, or remove the cap for easy fill like with your windshield washer fluid.
With your brake fluid, you don’t want to open up the cap unless you plan on replacing the fluid. Opening it up invites moisture to settle inside, and as we already discussed, moisture isn’t something you want in the hydraulic system.
New brake fluid will be clear to a slightly-amber color when you first put it in. If you find your brake fluid has signs of rust or is a darker, dirtier color, it’s time for it to be serviced.
Are there different types of brake fluid?
Because brake function is so important, it stands to reason that there are different types of brake fluid for different levels of performance. Yet you don’t head down to your local auto parts store and find brake fluid brands and types on the shelf in the same manner as motor oil.
The two main types of brake fluid are either a glycol-based or silicon-based.
Glycol-based brake fluids are normally used in vehicles that use anti-lock brakes (ABS). Silicon-based brake fluids work only in cars that don’t have ABS braking system. The two are not interchangeable. You can’t add in silicon-based brake fluid after glycol-based brake fluid has been in the system. Small amounts will always remain, no matter how much you flush the system.
The Department of Transportation has labeled brake fluids as DOT3, DOT4, and DOT5. DOT3 and DOT4 are glycol-based, while DOT5 is silicon-based. DOT3 and DOT4 absorb water. DOT5 doesn’t.
The number indicates the boiling point of the fluid. The higher the number, the better quality and higher chance of withstanding higher temperatures. But that doesn’t mean every vehicle operates better with a higher brake fluid. Check your owner’s manual for details on which brake fluid is best for your car.
It’s also important to note that glycol-based brake fluids eat paint, so it’s important to let a trained mechanic handle brake fluid.
Can I change my car’s brake fluid myself?
By reading this article, you’ve probably determined that brake fluid is more difficult to work with compared to other fluids in your vehicle. It’s not a typical do-it-yourself project. Brake fluid should only be handled by someone with professional training.
Brake fluid is both more complicated and more dangerous to work with than other parts of your car. It’s not as simple as picking up a gallon at your favorite big box store and adding it to the reservoir.
There are two types of brake fluid, and they don’t mix. If you do, you risk damaging your vehicle. That can be an expensive endeavor. It’s important to choose the right fluid based on manufacturers’ guidelines, and placing it into your vehicle in a proper manner.
You’ll also find brake fluid hard to dispose of. It’s both toxic and combustible, so you don’t want to leave it sitting around in your garage. It has specific guidelines for disposal, one that your mechanic has access to and uses every day.
A well-trained mechanic knows the ins and outs of how to handle every aspect of your braking system, including brake fluid maintenance and removal.
To ensure the reliability of your car, and the safety of you and your family, let one of our trained mechanics help you with all of your vehicle’s needs.