The concentric slave cylinder is a key part of the clutch on modern vehicles and replaces the fork, guide and clutch release bearing in a traditional clutch. The benefits of using a concentric slave cylinder are numerous, and include a lighter use of the clutch pedal which can minimise wear to the clutch pedal and the inner clutch mechanism.
The concentric slave cylinder is mounted inside the bell-housing on the gearbox, and is commonly made out of aluminium or thermoplastics. Inside the concentric slave cylinder consists of chambers and lubricated rubber seals which allows the hydraulic fluid to pass through. These seals must be high quality, as hydraulic fluid that is leaked through the seals will damage the material on the disc. This material is responsible for creating friction and if it is damaged, the clutch will fail to operate.
It is important to ensure that the concentric slave cylinder is not compressed before fitting as the seals that are inside the cylinder are prone to damage if they are compressed due to lack of lubrication.
If your concentric slave cylinder fails, you may notice a dropped or light clutch pedal.