Check out this video for a more detailed look at exactly what happens inside the brake booster. Hydraulic boosters are most common on diesel engine vehicles, as they do not produce vacuum.

Brake boosters assist drivers by multiplying the ... an electric pump (diesel engines produce little or no engine vacuum) or hydraulic pressure (usually the pressure of the power steering pump).

The 1950s marked the advent of power brakes, which increase the amount of hydraulic pressure pushed towards the master cylinder with the help of a booster. Most modern brakes today consist of some ...

Eliminating the hydraulic system of pipes, brake cylinders, brake boosters and antilock control units lowers vehicle weight, increases reliability, and reduces maintenance requirements.