Most cars equipped with a manual transmission today use a hydraulic clutch. This method is often used when the mechanical design of the car makes it difficult to use levers and cables. It is also used to multiply force, reducing driver fatigue.

With a hydraulic clutch, when you press the clutch pedal, it moves a small cylinder called the "master" cylinder. Pressure is created in the master cylinder which is, in turn, transmitted to the "slave" cylinder. The slave cylinder is attached to the throw-out fork by a small adjustable rod, so when pressure is exerted on the slave cylinder, it operates the fork. Both master and slave cylinders are designed in such an uncomplicated way that they are easy to attach with hydraulic tubing.