Vacuum servo


Vacuum servo

A vacuum servo is a component used on motor vehicles in their braking system, to provide assistance to the driver by increasing the braking effort.

It is used on virtually all vehicles which use hydraulic brakes for their primary braking circuit. Vacuum servos are not used on vehicles which use cables, rods (or other mechanical linkages), or pressurised air systems for their primary brake circuits.

It utilises a stored vacuum to multiply braking force applied by the driver to the brake pedal, before applying the transferred force to the brake master cylinder.

The vacuum is generated in two distinct methods, dependent on the type of internal combustion engine, or other motive force (as in electric vehicles). In petrol engines, the manifold vacuum is utilised, whereas in diesel engines, a separate vacuum pump is used. The the vacuum is transferred to the servo along semi-rigid plastic lines, and is stored in the servo by utilising a non-return valve.

External links

* [http://www.tr6web.com/Documents/tr6/brakebooster.html "Brake Booster Info"]
* [http://www.howstuffworks.com/power-brake.htm "How Stuff Works"]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • vacuum servo — See vacuum brake booster …   Dictionary of automotive terms

  • Vacuum — This article is about empty physical space or the absence of matter. For other uses, see Vacuum (disambiguation). Free space redirects here. For other uses, see Free space (disambiguation). Pump to demonstrate vacuum In everyday usage, vacuum is… …   Wikipedia

  • Vacuum pump — A vacuum pump is a device that removes gas molecules from a sealed volume in order to leave behind a partial vacuum. The vacuum pump was invented in 1650 by Otto von Guericke. Types Pumps can be broadly categorized according to three… …   Wikipedia

  • servo — [1] A servo motor supplies power to a servo mechanism. A servo mechanism is a low power device (electrical, hydraulic, or pneumatic) used to put in operation and control a more complex or powerful mechanism. [2] An oil operated device used to… …   Dictionary of automotive terms

  • servo motor — [1] A small electric motor that supplies power to a servomechanism [2] A calibrated vacuum or electrical motor used to position valves or doors in an automotive air conditioning system …   Dictionary of automotive terms

  • Manifold vacuum — Not to be confused with Vacuum manifold. Manifold vacuum, or engine vacuum in an internal combustion engine is the difference in air pressure between the engine s intake manifold and Earth s atmosphere. Manifold vacuum is an effect of a piston s… …   Wikipedia

  • List of vacuum tubes — This is a list of vacuum tubes or thermionic valves. Before the advent of semiconductor devices, hundreds of tube types were used in consumer and industrial electronics; today only a few types are still used in specialized applications. Contents… …   Wikipedia

  • brake servo — A device which multiplies the driver s physical effort in applying the brakes by using manifold vacuum …   Dictionary of automotive terms

  • master vac servo unit — See vacuum brake booster …   Dictionary of automotive terms

  • power servo — A vacuum operated or electrically powered device that actuates the duct doors and switches on systems equipped with automatic temperature control …   Dictionary of automotive terms


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.