Brakes are undoubtedly one of your car’s most crucial safety systems. Featuring an array of different components all working together, they help you manoeuvre, slow and stop your vehicle in a safe and controlled way. But how exactly do these systems work?
The brakes in your car may be more complicated that you realise. These systems include elements such as discs, pads, cylinders, drums, shoes, callipers, brake fluid and more.
The brake pedal that you press when you want to slow down or stop is connected to a master cylinder, which is located in the engine compartment. This cylinder contains brake fluid, and when you use the pedal, you create hydraulic pressure inside the cylinder. This forces brake fluid along pipes and hoses to hydraulically activated pistons located in the wheel hubs. In turn, this pushes the brake pads or shoes onto rotating parts of your wheels, and this is what slows and stops your car.
The two most common types of braking systems are disc brakes and drum brakes. Most cars are also now fitted with anti-lock braking systems (ABS) as standard.
The main elements of drum brakes are hydraulic wheel cylinders, a brake drum and brake shoes. When the brake pedal is activated, hydraulic wheel cylinders force two curved brake shoes fitted with a friction material lining onto the inner surface of a rotating brake drum. This slows the vehicle down or brings it to a stop
These systems feature a brake disc, brake pads and a brake calliper. The pads are fitted inside the calliper very close to the brake discs. When the brake pedal is pushed, hydraulic fluid forces the brake pads against the sides of the spinning brake discs, and this contact creates friction to slow or stop the vehicle.
Anti-lock braking systems
Now included as standard in most vehicles, ABS is designed to prevent the wheels from locking up when the brakes are pressed suddenly and sharply. By stopping wheels from seizing up in this way, the system helps to ensure that your tyres maintain their grip on the road, allowing you to keep control of your car and reducing the risk of accidents.
First introduced in the 1950s to prevent aircraft from skidding on runways, ABS has become an increasingly common feature of road vehicles. These systems are now present in all new cars sold throughout Europe. In a vehicle with ABS, each wheel has a sensor attached to it. If this sensor detects that the wheel is about to lock, it will release the brake for a moment. The system then applies optimum braking pressure to each wheel to ensure maximum braking power without causing the wheels to seize up. You might feel a temporary pulsating sensation through the brake pedal if your ABS kicks in.
If you drive an older car that doesn’t have ABS, you can simulate the effect of this system by pumping the brake pedal rapidly, meaning you apply and release it repeatedly.
How to spot a problem with your brakes
You’ll know if there’s a fault with your ABS because each time you turn your vehicle’s ignition on, this system tests itself. If there’s a problem, a warning light will appear to inform you that you need to get your ABS checked out.
When it comes to noticing issues with your brakes more generally, there are a number of warning signs to watch out for. For example, you should book a brake inspection if you notice a grinding or squeaking noise, sponginess or a lack of responsiveness, or if your car is pulling to one side. You should also arrange for a technician to look at your brakes if you feel a continuous pulsating motion from the pedal.
Wear and tear
We recommend that brake pads are replaced if the friction material has worn down to 3mm or less, while brake discs should be replaced if they show signs of excessive wear or damage. Brake drums or discs should be replaced in axle sets, rather than individually. If you replace just one, this could make your braking system imbalanced. One possible effect of this is that it could lead to accelerated wear and tear as you use your brakes.
The importance of regular checks
When you take your car for a service, the technician will make sure that all the elements of your braking system are working correctly, and they will repair or replace any components if necessary. If you suspect there is something wrong with your brakes before your next service is due, you should book in for a separate brake check.
We recommend getting your brakes looked over at least twice a year. As well as helping to keep you and other road users safe, this will give you extra peace of mind when you’re behind the wheel.