A clutch is a friction plate, pressed between the flywheel and a pressure plate. A large disc spring, called a diaphragm spring, pushes the pressure plate towards the flywheel. When the driver disengages the clutch, a lever pushes the centre of the diaphragm spring until it flips inside out, disengaging the clutch plate. A bearing between the lever and the diaphragm spring facilitates a low friction contact between the stationary lever and the spinning clutch spring.
There are two common ways to operate the lever in the clutch assembly: by means of a Bowden cable or hydraulically. On hydraulic systems, the driver operates a hydraulic master cylinder by means of a clutch pedal. The master cylinder is a pump, which pumps brake fluid to a slave cylinder. The rising amount of brake fluid in the slave cylinder forces a piston out of the cylinder. The piston connects to the clutch assembly lever and thus disengages the clutch.
Brake fluid is hygroscopic. It attracts and absorbs water over time, causing corrosion inside the cylinder. That's why brake fluid in hydraulic clutches has to be changed every two years, removing dirt and wear particles in the process. Failing to change the fluid will cause wear and corrosion, resulting in leaks and poor clutch operation.
If the clutch doesn't disengage properly, when the gearbox feels jerky or if brake fluid disappears from the clutch master cylinder reservoir, its time to replace the clutch cylinders. As manufacturing tolerances, surface roughness and the rubber quality of seals have a big influence on clutch feel, clutch operation and life span of the cylinders themselves, it is essential to choose high quality replacement parts. That's why Nipparts developed a wide range of clutch cylinders in OE matching quality. You can find our clutch cylinder range in the free online catalogue.
Nipparts Clutch Cylinders:
- Carefully chosen tolerances
- High quality seals
- Machined to low surface roughness
- OE matching quality