Genuine BOSCH Clutch Slave Cylinder
Part number JB4203

A clutch slave cylinder is an integral part of a car's hydraulic clutch system. It helps in the smooth operation of the clutch by transferring hydraulic pressure from the clutch master cylinder to the release fork, which in turn engages and disengages the clutch. The slave cylinder is typically mounted on the exterior of the gearbox, near the clutch housing.

When the driver applies pressure to the clutch pedal, the clutch master cylinder sends hydraulic fluid down to the clutch slave cylinder. This fluid pressurizes the slave cylinder, causing the release bearing to push against the clutch diaphragm spring. As a result, the clutch is disengaged and power transfer from the engine to the transmission is interrupted. Conversely, when the driver releases the clutch pedal, the hydraulic pressure in the slave cylinder decreases, allowing the clutch to engage and power to be transmitted smoothly once again.