Editing Master cylinder (section)

{{Short description|Control device that converts force into hydraulic pressure}}
{{for|the album by Caveman Shoestore|Master Cylinder (album)}}
{{refimprove|date=June 2018}}
[[File:2008-04-21 1990 Geo Storm GSi master cylinder.jpg|thumb|right|A master cylinder from a [[Geo Storm]]]]
[[File:Master cylinder diagram.svg|thumbnail|right|Master cylinder schematic for a [[dual brake circuit]] ]]

In [[automotive engineering]], the '''master cylinder''' is a control device that converts [[force]] (commonly from a driver's foot) into [[hydraulic pressure]].<ref>{{Cite web |title=Master Cylinders |url=https://majorsell.co.uk/master-cylinders |publisher=Majorsell Limited}}</ref>  This device controls '''slave cylinders''' located at the other end of the [[hydraulic brake]] system and/or the hydraulic clutch system.

As [[piston]](s) move along the [[Gauge (bore diameter)|bore]] of the master cylinder, this movement is transferred through the [[hydraulic fluid]], to result in a movement of the [[Master/slave (technology)|slave]] cylinder(s). The hydraulic pressure created by moving a piston (inside the bore of the master cylinder) toward the slave cylinder(s) compresses the fluid evenly, but by varying the comparative surface area of the master cylinder and each slave cylinder, one can vary the amount of [[force]] and displacement applied to each slave cylinder, relative to the amount of force and displacement applied to the master cylinder.<ref >{{cite web|url=http://www.peterverdone.com/archive/files/hydraulic%20system%20theory.pdf|format=PDF|title=Chapter 7 : Basic Hydraulic System Theory|website=Peterverdone.com|accessdate=2018-07-06}}</ref>