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Your vehicle’s brake system is one of the most important components on your car. Some knowledge about what kind of brakes you have and how they work is essential when determining their maintenance schedule. Brake technology has come a long way from drum to disc and the Anti-lock Braking System (ABS). Here’s how to identify which braking system you have, how they work and when you should replace them.
Drum Brakes
If you own an older vehicle, chances are you have drum brakes. Considered a more primitive design, the components are encased in a round drum that spins with each wheel, located on each of the four wheels. Each drum contains two “shoes,” which, as the brake pedal is pressed, push up against the sides of the drum, slowing the wheel down. While this system was suitable at the time, a downside was discovered: the brakes faded, losing their effectiveness. In high braking situations, such as slowing down from a fast speed or repetitive stops, the friction caused heat to build up within the drums. As they expand from the heat, the shoes have to be pushed out further to make contact, forcing the driver to press the brake pedal harder. As a result, drum brakes perform at their best when they are able to handle the amount of heat generated from the slowing of the wheels, which is inconvenient to the driver.
Disc Brakes
In today’s vehicles, disc brakes are common. The system uses a flat, disc-shaped rotor that spins the wheel. When the brake pedal is pressed, a caliper, which contains a brake pad located on each side of the rotor, clamps down on the disc, slowing the wheel. Compared to drum brakes that have the heat buildup problem, disc brakes are able to cool down more effectively since they are exposed to the open air. With the air cooling the rotors, the brakes are less likely to overheat or fade.
Disc brakes also tend to be more effective in wet driving conditions. Drum brakes can collect water on the inside where the brake shoes come in contact with the drums, whereas centrifugal force repels the water off the disc, keeping it dry. But disc brakes have a disadvantage as well: because they are exposed to the outside air they are likely to attract dirt and dust between the rotor and pads, wearing them out quicker.
ABS
Introduced to cars in the mid-1980s, ABS can help a driver have some control in their steering as well as enabling them to avoid skidding in an emergency braking situation. ABS works on all four wheels of your car, which assists in directional stability when used correctly.
The basic idea of ABS is that they keep your brakes from locking up. When your foot slams down on the brake pedal, the system pumps the brakes, preventing seizure. On a vehicle without ABS, the driver can manually pump the brakes by continuously pressing on the pedal. Preventing lock up allows the driver to have steering control, which can help you avoid crashing into a hazard.
The system uses speed sensors on the wheels to detect if one or more wheels are trying to lock up. If a wheel is trying to lock up, hydraulic valves limit or reduce the braking on that wheel. Ways to tell if ABS has been activated:
- a groaning noise
- a rapid pulsing of the brake pedal
- a periodic dropping of the brake pedal
- a hard (non-compliant) brake pedal
- a light that turns on to say “low traction”
Signs You Should Replace Your Brakes
The brake pads will wear down over time, decreasing the ability to stop the vehicle.
Disc brakes will usually come with a wear indicator, a small piece of metal attached to the brake pad. When the pad is worn out the indicator will grind against the rotor, making a high-pitched squeal when the brakes are applied. This is an important sign to have your brakes examined.
A low or spongy brake pedal, a red brake-warning, or yellow brake-warning light for the ABS system are also signs you should have your brakes checked out as soon as possible.
Not properly maintaining your brakes can be dangerous, so don’t wait too long when it’s time to change the pads. In an emergency situation it is a must to have properly functioning brakes, so be sure to have them inspected at least once a year.
Photo:
www.caradvice.com.au
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