Brakes wear out over time requiring service
When driving, it’s second nature to stop your car at red lights, stop signs and when you’re ready to park the car. But sometimes, it’s also important that your vehicle be able to stop – quickly, to avoid hitting other cars, pedestrians or objects in the road.
The braking system is easily one of the most
important system in your car. Brakes are such a basic function that
it’s easy to take them for granted until it’s too late.
Applying the Brakes = Applying Great Force and Energy
When you step on the brake, your car transmits the force from your foot to its brakes through a fluid, commanding a stopping force ten times as powerful as the force that puts the car in motion.
On most cars, the front brakes are of the disc type, and the rear brakes are of the “drum” type, which use two semi-circular shoes to press outward against the inner surfaces of a steel drum. Older cars often had drum brakes on all four wheels, but many newer cars now have 4-wheel disc brakes.
The brake system contains the following basic components:
Disc brakes produce friction between the
rotor and the pads mounted in the caliper attached to the suspension
members with a clamping action. Inside the calipers, pressure generated
by the master cylinder causes the pistons to press against the pads. The
pads then rub against the rotor, which causes the car to slow.
Disc brakes are simpler, lighter and offer better resistance to water than drum brakes.
The brake drum is a heavy flat-topped cylinder,
located between the wheel rim and the wheel hub. The linings of the
brake shoes work on the inside surface of the drum. Once the brakes are
applied, the brake shoes come in contact with the inside surface of the
brake drums and slow the rotation of the wheels.
While most older cars have drum brakes on the rear wheels, newer models are more likely to use rear disc brakes.
The caliper works like a C-clamp to pinch the pads onto the rotor. One caliper is mounted to the suspension members on each wheel. The caliper is usually mounted onto the spindle, allowing it to deliver the torsional force of the wheel to the chassis via the control arms. Brake hoses connect the caliper to the brake lines leading to the master cylinder. A “bleeder valve” is located on each caliper to allow air bubbles to be purged from the system.
Wheel cylinders are where movable piston(s) convert hydraulic brake fluid pressure into mechanical force. As the driver pushes down on the brake pedal, pistons move within the master cylinder and pressurize the brake fluid in the brake lines and cylinders at each wheel. In turn, the fluid pressure causes the wheel cylinders’ pistons to move which then forces the shoes or pads against the brake drums or rotors.
The parking brake (sometimes called the emergency brake) is a cable-activated system used to hold the brakes continuously in the applied position. The parking brake activates the brakes on the rear wheels. Instead of hydraulic pressure, a cable (mechanical) linkage is used to engage the brake shoes or discs. When the parking-brake pedal is pressed (or, in many cars, a hand lever is pulled), a steel cable draws the brake shoes or pads firmly against the drums or rotors.
“Anti-lock” (ABS) systems use computer-controlled valves to limit the pressure delivered to each wheel cylinder. If a wheel locks up, no matter how hard you steer you cannot affect the car’s direction. With ABS, no matter how hard the pedal is pressed, each wheel is prevented from locking up. This prevents skidding (and allows the driver to steer while panic-braking).
Helps You Maximize Your Stopping Power Regular maintenance on your car’s brakes is just as important as it is to your engine. Have them checked at least once a year, more if you drive frequently in city traffic or live in a hilly area. Waiting until the brakes begin to grind can be more expensive, but a few simple steps will help keep your brakes in good working order.
When to Visit Your Just7 Lube & Tune.
Things to look for when you apply the brakes: