The slave cylinder is a hydraulic cylinder and a release bearing combined. It allows the clutch disc to move in order to engage or disengage the drive. Its main advantage over the traditional system comprised of a bearing, fork and rollers, is lower weight, bigger strength and higher reliability. Nevertheless, it too wears with time causing leaks and affecting the clutch operation. The slave cylinder is routinely replaced together with the clutch assembly.
What is the role of the clutch?
The clutch engages or disengages the drive between the engine and the transmission, allowing smooth pulling away and stopping your car, as well as changing gears, without having to turn off the engine.
What does the clutch look like?
The clutch is comprised of a friction plate, which is pressed by the pusher plate to the engine flywheel. The clutch plate is secured to the clutch shaft and controlled by the thrust bearing. Its motion is initiated by pressing and releasing the clutch pedal.
When should the clutch be replaced?
The friction lining of the clutch plate gradually wears out, causing the plate to slip and preventing it from transmitting the torque from the engine to the other elements of the drive unit. If this is the case, the clutch must be replaced, which requires disassembling the gear box. Cars equipped with a front wheel drive require detaching the suspension and removing the half-shafts. Cars equipped with a rear wheel drive require disconnecting the transmission shaft in order for the gear box to be removed. Next, the pusher plate is unscrewed, followed by the removal of the clutch plate. As the useful life of the pusher plate springs and the thrust bearing is limited, these elements must be changed together with the clutch plate, as together they comprise the clutch assembly.
What to keep in mind?
In cars, in which the clutch is controlled by means of a hydraulic system instead of a cable connected to the clutch pedal, the clutch slave cylinder must also be replaced. When fitting a new clutch, you should also check the level of wear of the flywheel surface. If your car is equipped with the so-called dual mass flywheel, a good idea is to replace it along with the clutch, as it gradually wears, too. After changing the clutch you should have the hydraulic clutch control system deaerated and a test drive performed to check if the drive system operates properly. It is difficult to determine when the clutch should be replaced, nevertheless in a typical car driven mainly in the city this component becomes worn after about 100 thousand kilometres."