A brake is a device for slowing or stopping the motion of a machine or vehicle. The brake system is composed of the following basic components: The master cylinder, which is located under the hood and is directly connected to the brake pedal, converts your foot’s mechanical pressure into hydraulic pressure. Brake lines and flexible brake hoses connect the master cylinder to the slave cylinders located at each wheel. Brake fluid fills the brake lines, hoses, calipers, and reservoir. Shoes and brake pads are pushed by the slave cylinders to contact the drums and rotors thus causing friction which slows the vehicle down.
The master cylinder is a control device that converts physical pressure typically from a driver’s foot applying pressure on the brake pedal, into hydraulic pressure to operate other devices in the hydraulic system. In brake systems, the operated devices are brake calipers. The master cylinder sends hydraulic pressure to the rest of the brake system.
There are two separate systems that may be supplied by separate fluid reservoirs, or they may be supplied by the same reservoir. Most brake systems today are divided into front and rear. Some can be diagonally separated.
The modern brake booster is a brilliant device that operates using engine vacuum, engine vacuum is generated whenever the engines running. The brake booster takes engine vacuum via a rubber hose that runs from the intake manifold. The brake booster uses that vacuum to amplify the pressure you put on the pedal ensuring that your car stops more rapidly. What happens to the brake booster if your car stalls and loses its vacuum? Engineers realized early on that gas engines were not foolproof, so they engineered a. check valve within the brake booster circuit. The brake booster stores enough vacuum to provide full boost for two or three pedal applications after the engine stalls. The check valve on the brake booster is what keeps that vacuum from leaking out. If the brake booster can’t hold vacuum its time is up and you’ll need a new or remanufactured brake booster.
The difference between disc brakes and drum brakes is focused on the design of the brake system component closest to the wheel. In a disc brake system, a brake rotor is mounted either directly behind the wheel or on the axle that supports the wheel. It is mounted in a way that it turns with the wheel and can exert a force on the wheel for the purpose of slowing or stopping the vehicle. The brake disc looks similar to a wide brim hat, with the portion that looks like the brim serving as the friction surface. A brake caliper is mounted in such a way that a pair of brake pads can be squeezed against the rotor (brim) increasing friction and causing the rotor to slow or stop.
In a drum brake system, the brake drum is mounted directly behind the wheel, sandwiched between the wheel and its hub. The brake drum looks like a bowl with vertical sides. The balance of the drum components are mounted to a stationary backing plate inside the drum. Brake shoes are mounted on the backing plate via springs with the slave cylinder mounted between them on one end. When brake fluid is added to the slave cylinder by the operator pressing the brake pedal, the shoes are pressed against the sides of the drum, increasing friction and causing the drum to slow or stop.
The brake caliper is a U-shaped device with a piston or pistons on one or both sides of the U. The brake pads sit in front of the piston(s) on each side of the U-shaped caliper. When the brakes are applied, high-pressure fluid is channeled from the master cylinder to the brake caliper where it pushes the piston(s) inward. This action moves the pads against the spinning brake rotor, and the friction stops your vehicle. There are two types of calipers, a floating or a fixed caliper. A fixed caliper does not move relative to the disc. It uses two. or more pistons to clamp from each side of the disc, and is more complex and expensive than a floating caliper. A floating caliper moves with respect to the disc; a piston on one side of the disc pushes the inner brake pad until it makes contact with the brake rotor surface, then pulls the caliper body with the outer brake pad so pressure is applied to both sides of the disc.
A brake is a device for slowing or stopping the motion of a machine or vehicle, and to keep it from starting to move again. The kinetic energy lost by the moving part is usually translated to heat by friction. In a disc brake system, brake pads are the parts of a car’s braking system that actually take the brunt of the force necessary to stop the car. The brake pedal pushes fluid through a hydraulic line which causes the piston in the caliper to squeeze the brake pads against the rotors. Brake pads are positioned between the calipers and the rotors to absorb the energy and heat, and then provide enough grip to stop the car. Each time the brakes are applied, a small amount of the friction material on the brake pad is worn away. Thus the brake pads are a consumable element of the braking system and need to be replaced as they wear.
Slave cylinders (also known as wheel cylinders) are cylinders where movable pistons convert hydraulic brake fluid pressure into mechanical force. Hydraulic pressure against the pistons within the wheel cylinder forces the brake pads against the surface of the rotor. There is one cylinder/caliper (usually) for each individual wheel.
A brake is a device for slowing or stopping the motion of a machine or vehicle, and to keep it from starting to move again. The kinetic energy lost by the moving part is usually translated to heat by friction. In a drum brake system, brake shoes are the parts of a car’s braking system that actually take the brunt of the force necessary to stop the car. The brake pedal pushes fluid through a hydraulic line which causes the slave cylinder in the drum to push the brake shoes against the inside surface of the drum. Brake shoes are positioned between the slave cylinder and the drum to absorb the energy and heat, and then provide enough grip to stop the car. Each time the brakes are applied, a small amount of the friction material on the brake shoe is worn away. Thus, the brake shoes are a consumable element of the braking system and need to be replaced as they wear.
ABS (Anti-lock Braking System) was originally developed for aircraft braking systems. When used properly, an antilock brake system (ABS) is a safe and effective braking system. ABS allows the driver to maintain directional stability, control over steering, and in some situations, to reduce stopping distances during an emergency braking situation, particularly on wet and slippery road surface. To gain this safety advantage, drivers must learn how to operate their ABS correctly.
An antilock braking system works with the regular or foundation brakes on your vehicle. ABS simply keeps your base brakes from locking up. In vehicles not equipped with ABS, the driver can manually pump the brakes to prevent wheel lockup. In vehicles equipped with ABS, the driver’s foot remains firmly on the brake pedal, allowing the system to automatically pump the brakes.
ABS will help you maintain control of your vehicle when road conditions aren’t optimal. When your brakes lock up on wet and slippery roads or during a panic stop, you lose steering control and your vehicle can spin. Rear wheel ABS prevents wheel lockup so that your car stays in a straight line. If your car has ABS control on all four wheels, you also keep steering control. If you have steering control, it is possible to avoid a crash by steering around hazards if a complete stop cannot be accomplished in time.
Most new car models offer ABS as either standard or optional equipment. When the ABS is working, drivers may experience a rapid pulsation of the brake pedal–almost as if the brakes are pushing back at you. Sometimes the pedal could suddenly drop. Also, the valves in the ABS controller may make a noise that sounds like grinding or buzzing. In some cars you may feel a vibration–this means the ABS is working. It is important NOT to take your foot off the brake pedal when you hear noise or feel pulsations, but instead continue to apply firm pressure. You should not pump your brakes if you have ABS. Just hold your foot firmly on the brake pedal and remember that you can still steer.
