What is brake fluid?

There are a number of different fluids in a car, each one serving an important function to make sure your vehicle runs smoothly and safely on the road. Everyone knows what certain fluids do and why you have to service them, like petrol or oil, while others can be a little more confusing. Brake fluid is a really important item, but what does it actually do and when should it be serviced?

What Does Brake Fluid Do?

As the name suggests, brake fluid is one of the major components required to make sure your brakes work effectively to stop your car. The way it does this is by acting as a hydraulic fluid, something it excels at because liquids are very difficult to compress. When you press your brake pedal, the fluid transfers and amplifies the force you’ve applied to pedal through to the brake pads (or shoes in the case of drum brakes) – which squeeze the brake disc (or push the shoes onto the drum in the case of drum brakes) to slow down the wheels and your car.

The reason we have developed a specific product for this job is because of the heat generated by the braking process. Under a regular street driving load, the brakes in your car can reach up to 200°C, and under a more aggressive braking load (such as going down a mountain or racing on a track), your brakes can get over 500°C! As the brake fluid is in close proximity to all of this heat, it needs to be able to operate without boiling as this can create air bubbles, stopping any or all of the brake pedal force from reaching the actual brakes. In colder climates, the brake fluid needs to be able to withstand below 0°C temperatures without freezing, causing damage to the brake lines and stopping the liquid brakes from working.

Specific brake fluid has been developed to operate in a wide range of temperatures from -40°C and 260°C, meaning you can be confident it’ll do the job that’s needed of it in almost any situation.

How To Tell If Your Brake Fluid Needs A Service

The most obvious indicator that your brake fluid is low is that your brake warning light will be illuminated. Most modern vehicles have a sensor inside the brake system that notifies you if it is time for a service. However, if you notice any of the follow signs, it’s time to get your brakes serviced:

• A mushy, marshmallow like feeling when you press the brake pedal
• The vehicle is more difficult to stop
• A delayed response when you press the brake pedal
• Your brake pedal depressing further than usual

These signs can indicate your brakes may have a reduced amount of fluid in them, air in the lines, a leak, low brake pads or a number of other possible brake issues. To ensure the safety of your vehicle, never ignore any warning signs your car is giving or a change in brake effectiveness.

How Often Should I Replace Brake Fluid? (And Is It Included In A Service)

How you use your car can affect how often you need to have your brake fluid replaced, but a good rule of thumb is to have your mechanic check your fluid whenever you have your oil change done or if you notice any changes in your braking (e.g. spongier pedal, less braking effectiveness or a delayed response). At Australian Mechanical, a brake fluid check is performed whenever you get a service done with us, so you can drive away with peace of mind knowing your vehicle is safe to hit the roads.

If for whatever reason you have concerns with your brakes however, don’t hesitate to contact Australian Mechanical today, and arrange an inspection for your vehicle.