Braking System Repairs at West Coast Tire and Service
Modern automotive braking systems combine leverage and multiplied hydraulic force to stop your vehicle. Once your foot presses the brake pedal, pressure is generated to slow or stop the vehicle.
Applied at the brake pedal, the driver's braking effort is multiplied by the brake booster and then applied to the master cylinder. The master cylinder transmits the braking effort-via the brake fluid-to the brake calipers (on disc brakes) or to the wheel cylinders (on non-disc brakes). Consistent with the driver's pedal effort, first the calipers press the brake pads against the brake rotors. Then the wheel cylinders apply the brake shoes against the brake drums, thereby stopping the vehicle.
Most new cars have anti-lock brakes (ABS) for faster, safer braking. The parking/emergency brake can be used as a mechanical or electronic backup in case the hydraulic system fails.
Braking System Components
- Brake fluid transmits the force from the brake pedal to each wheel. Brake fluid degrades over time and needs to be replaced as a part of regular vehicle maintenance around every 2 years.
- The master cylinder is linked to the brake booster and in turn to the brake pedal. It regulates the fluid pressure exerted onto the brake discs or drums. When the brake pedal is pressed the master cylinder creates hydraulic pressure in the brake lines. This pressure pushes pistons in the caliper that force the brake pads against the rotors. On drum brakes, the wheel cylinder forces the brake shoes against the drums. The harder the brake pedal is pressed, the greater the pressure created by the master cylinder, and the faster the car stops.
- It takes a significant amount of force to stop a vehicle. It would be very difficult for a typical driver to produce this force without a brake booster. Located between the brake pedal and the master cylinder, the booster is powered by the vacuum created by either the engine or an electric pump.
- Nearly all modern vehicles are equipped with disc brakes on their front wheels. Disc brakes consist of a brake rotor (disc), a brake caliper and two brake pads per wheel. Friction is generated when the calipers force the pads against the rotors, thus slowing the rotation of the wheel and the car.
- Drum brakes are more common on older vehicles, although some modern vehicles still use them in the rear. Drum brakes consist of a wheel cylinder, brake shoe and a round brake drum that rotates with the wheel. When the brake pedal is pressed the wheel cylinder pushes the brake shoes outward against the drum. The resulting friction slows the rotation of the wheels and the car.
- If you've ever felt and heard the electronic pulsation of your brakes under heavy braking, you've experienced anti-lock brakes (ABS). First introduced in the 1970s, they're now standard on almost all vehicles-and for good reason. Skidding wheels have less traction and don't turn as well as non-skidding wheels. In slippery conditions or under heavy braking, ABS help keep your wheels from skidding, so you can stop faster while still being able to steer. An ABS control module continually measures the speed of each wheel. With the help of a wheel speed sensor, the module is able to tell when a wheel is starting to skid. If it senses that the wheel is locking up, the module temporarily releases and applies brake pressure with as many as fifteen pulsations per second to slow both the wheels and vehicle as quickly and safely as possible.
- The parking/emergency brake can be used as a non-hydraulic brake system backup. It can be either cable- or electronically-operated. By pressing the parking brake pedal or pulling the parking brake lever, the driver is pulling a cable that activates the rear brakes. The cable may operate the existing brakes or it may have its own assembly inside the hub of the rear rotors.
Brake System Maintenance
Most of us don't think about our car's brakes until we need them for a panic stop, hear a screeching or grinding noise or when a warning light comes on. But brakes are worn down every time you drive your car. It's important to keep them maintained and serviced-before you hear that screeching. The sooner the better ... and cheaper.
All cars incorporate some type of brake warning system to inform the driver of a problem. A warning light is the most common. It typically alerts a driver to:
- Low brake fluid
- Brake system hydraulic pressure failure
- An applied parking brake
- An ABS malfunction
- Brake pads need replacement
- An inoperative brake bulb
Some systems have metal clips that rub on the rotors when pads are worn out. This causes a high-pitched, fingernails-on-a-chalkboard screech when the brake pedal is pressed. Some newer vehicles alert the driver in a more civilized and agreeable manner with warning lights or computerized messages. No matter which your vehicle has, it's critical to address the issue promptly. WestCoast Tire and Service can use Aftermarket or Original Equitment Manufactured parts.