A vacuum servo is a component used on
motor vehicles in their
braking
A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction.
Backgroun ...
system, to provide assistance to the driver by decreasing the braking effort. In the US it is commonly called a brake booster.
A vacuum servo also known as a power booster or
power brake
Power brakes are a system of hydraulics used to slow down or stop most motor vehicles. It uses a combination of mechanical components to multiply the force applied to the brake pedal by the driver into enough force to actuate the brakes and stop ...
unit uses a vacuum to multiply the drivers pedal effort and apply that effort to the
master cylinder
In automotive engineering, the master cylinder is a control device that converts force (commonly from a driver's foot) into hydraulic pressure. This device controls slave cylinders located at the other end of the hydraulic brake system.
A ...
.
It can not be used when the engine is off, mostly after a few attempts.
Notes
External links
What is a brake booster?
(a 4-page basic tutorial article, with illustrations & animation) at HowStuffWorks.com
Brakes
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