How Does a Hydraulic Clutch Operate?

Modern vehicles with manual transmission are usually equipped with a hydraulic clutch system instead of a conventional mechanical clutch. Both systems share the same function, which is to transfer the rotational movement of the engine to the transmission.

A hydraulic clutch consists of basic components: a master cylinder, slave cylinder, clutch fork, flywheel, clutch plate, pressure plate and clutch release bearing. The clutch moves with the engine, allowing a gradual and smooth transfer of power from the engine to the transmission, through the flywheel, which is bolted to the crankshaft.

When the clutch pedal is depressed, it pushes a rod that is linked to the master cylinder, which is connected to a hydraulic fluid reservoir. Hydraulic fluid then flows into the clutch slave cylinder, and the hydraulic pressure formed in the process activates a pushrod in the slave cylinder. The pushrod moves against the clutch fork pushing the clutch release bearing.

Pressure is further transferred to a diaphragm spring, pulling the pressure plate away from the clutch plate. At this point, the clutch is no longer engaged to the engine. The power is now interrupted, and the driver can shift the car into another gear without causing damage to the transmission.