Genuine Toyota Brakes Terminology | Phil Gilbert Toyota

Genuine Toyota Brakes Terminology | Phil Gilbert Toyota

Essential Automotive Terminology

Brake Booster

A brake booster is a device that reduces the amount of force required to depress the brake pedal. Vacuum type brake boosters use a pressure differential between the vacuum (negative pressure) created by the engine and atmospheric pressure, while hydraulic brake boosters use oil pressure

Brake Caliper 

A brake caliper is the part of a disc brake that is installed around the brake rotor. When the driver depresses the brake pedal, the brake caliper’s pistons push the brake pads against the rotor. In this way, frictional force is generated between the brake pads and the brake rotor to slow and stop the vehicle.

Brake Drum

A brake drum is the part of a drum brake that rotates with the tire. It is cylindrical in shape. When the driver depresses the brake pedal, the brake shoe is pressed against the brake drum from the inside. In this way, frictional force is generated to slow and stop the vehicle.

Brake Fluid

Brake fluid is a hydraulic fluid that transmits the force exerted by the driver on the brake pedal to the brakes on the vehicle’s four wheels.

When brake fluid is used for an extended period of time, it absorbs moisture from the air, making a phenomenon known as vapor lock more likely to occur.

Brake fluid reservoir tank

A brake fluid reservoir tank is a tank that holds brake fluid. Leaks in brake lines and wear of brake pads or linings will cause the fluid level in the brake system to fall. The reservoir should be kept filled so that the brake fluid level is between the MAX and MIN indications on the side of the tank.

Brake Master Cylinder

A brake master cylinder converts pressure on the brake pedal into hydraulic pressure. When the driver depresses the brake pedal, that force is transmitted to the master cylinder and then to the brake on each wheel via hydraulic fluid (brake fluid).

Brake Pad

In a disc brake, a pair of brake pads is mounted on the inside of the brake caliper to generate braking force. When the driver depresses the brake pedal, the brake caliper’s pistons push the brake pads against the brake rotor. In this way, frictional force is generated between the brake pads and the brake rotor to slow and stop the vehicle.

Brake Pad Wear Indicator

A pad wear indicator serves to inform the driver that it is time to replace the brake pads. A high-pitched, metallic squeal can be heard near the brakes when they are not being used, and this sound warns the driver that the brake pads are worn. The sound is not produced while the brake pedal is depressed. Some designs inform the driver via a display on the instrument panel.


Brake Rotor (or also known as brake disc)

The brake rotor is the part of a disc brake that rotates with the tire. When the driver depresses the brake pedal, the  rake caliper’s pistons press the brake pads against the brake rotor. In this way, frictional force is generated between the brake pads and the brake rotor to slow and stop the vehicle.


Brake Shoe

A brake shoe is the part of a drum brake that has the friction material (lining) applied to the outside of it. When the driver depresses the brake pedal, the brake shoe is pressed against the brake drum from the inside. In this way, frictional force is generated to slow and stop the vehicle.