A vacuum servo is a component used on
motor vehicle
A motor vehicle, also known as a motorized vehicle, automotive vehicle, automobile, or road vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on railway track, rails (such as trains or trams), does not fly (such ...
s 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.
Background
...
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 consist of a system of hydraulics used to slow down or stop a motor vehicle. It uses a combination of mechanical components and vacuum assistance to multiply the pressure applied to the brake pedal by the driver into enough force to ...
unit, uses a vacuum, usually supplied by the engine, to multiply the driver's pedal effort and apply that effort to the
master cylinder.
Because the servo depends on the vacuum supplied by a running engine, a check valve is typically used in the vacuum line to maintain residual vacuum without engine support, allowing limited use even after parking.
See also
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List of auto parts
This is a list of auto parts, which are manufactured components of automobiles. This list reflects both fossil-fueled cars (using internal combustion engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the c ...
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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