What Is a Brake Fluid Flush and Is It Really Necessary?

Has your mechanic recommended a brake fluid flush for your vehicle? Brake fluid is an essential component of automotive brake systems. Typically consisting of diethylene glycol, it's designed to transfer the mechanical force of the brake pedal being pressed into pressure. There are certain types of services, however, that involve the brake fluid, one of which is a brake fluid flush.

What Is a Brake Fluid Flush?

A brake fluid flush is an automotive service in which all of the existing brake fluid is removed from the vehicle and replaced with new brake fluid. It's a multistep process that ensures the vehicle's brake system exclusively contains new brake fluid.

Like most automotive fluids -- coolant, oil, etc. -- brake fluid can degrade over time. It will undergo chemical changes that negatively affect its ability to assist with braking. A brake fluid flush offers a solution. During this service, the mechanic will use a pressurized vacuum machine to suck out all of the old brake fluid, followed by pumping new brake fluid in its place.

Why Brake Fluid Flushes Are Important

Brake fluid flushes are important for several reasons. As previously mentioned, brake fluid doesn't last forever. Most experts recommend changing it at least once every few years. By the end of this period, brake fluid may have a different chemical composition that harms its performance.

You can always do a brake fluid exchange, which is a similar process that will provide your vehicle with new brake fluid. A brake fluid exchange, though, doesn't involve the use of a pressurized machine. It only involves draining and refilling the brake fluid. Unfortunately, this may result in contaminants like moisture being left behind. A brake fluid flush will remove both the old brake fluid and all contaminants from your vehicle's brake system.

How Often to Get a Brake Fluid Flush

You should check your owner's manual for more information on when to get a brake fluid flush. Some automakers recommend a brake fluid flush once every two years, whereas others recommend a brake fluid flush once every four or more years.

Keep in mind that your driving habits will affect your vehicle's brake system and, thus, how often you need to get a brake fluid flush. If you drive in a lot of stop-and-go traffic, you may need to get a brake fluid flush more frequently than other motorists who drive mostly on the open highway.