DESCRIPTION The clutch system consists of a clutch proper and control The clutch proper transmits power from the engine to the transmission and performs the following functions when the clutch pedal is operated Transmitting engine power smoothly to the transmission as the vehicle is started 2.Connecting and disconnecting engine power be transmission gear shifting Clutch Proper When the clutch pedal is depressed, the power cylinder (or clutch booster) is operated by the hydraulic pressure from the clutch master cylinder This causes the release bearing to push the release lever via the clutch release fork and fork shaft The release lever, operating on a force being applied with the support lever pin as the fulcrum, compresses the pressure spring As a result, the pressure plate is pulled back, cutting off power from the engine When the clutch pedal is released, the clutch disc is compressed against the flywheel by the pressure spring force, thus transmitting engine power to the transmission Clutch Control The clutch pedal mechanism is the pendant type When the pedal is depressed, the push rod is forced down into the master cylinder, causing pressurized fluid to move the clutch Booster The ;clutch booster doubles the hydraulic pressure which moves the clutch release bearing, thereby operating the clutch proper (Vehicle with clutch Booster) Clutch master cylinder When clutch pedal is depressed As the push rod pushes the piston, the supply valve is moved by the tension of supply valve spring, thus closing the gap As the piston is pushed further, the pressure in the cylinder is increased and is transmitted to the clutch booster 2.When clutch pedal is released The pressure built up in the cylinder, together with the tension of the return spring, forces the piston back causing the supply valve rod to come into contact with the supply valve stopper Then, the supply valve is opened to release fluid, thus eliminating hydraulic pressure Clutch booster The clutch booster is a hydraulically actuated device that multiplies the driver's clutch pedal effort The pneumatic circuit and hydraulic circuit are integrated into a unit Stationary Both chambers and are open to the relay valve exhaust port, maintaining atmospheric pressure This means that the power piston is being pushed by the return spring toward chamber The hydraulic piston is being pushed to the left by the clutch return spring The relay valve piston, on the other hand, is pushed toward the power cylinder by the valve spring The poppet valve is seated on its seat by the poppet spring, cutting off the passage of compressed air 2.Operating When the clutch pedal is depressed, the hydraulic pressure from the clutch master cylinder is applied to the relay valve piston and hydraulic piston As the hydraulic pressure overcomes the tension of valve spring, the relay valve piston moves toward the poppet valve, together with the diaphragm When the front end of diaphragm comes into tight contact with the poppet valve, the control chamber is separated from the air chamber As the hydraulic pressure from clutch master cylinder builds up, the poppet valve opens allowing compressed air to enter chamber from the control chamber Since chamber is open to atmosphere, there is a pressure difference produced between chambers and The force generated from this pressure difference then overcomes the tension of return spring, causing the power piston to push the hydraulic piston, thus moving the push rod The thrust being applied to the push rod is the sum of the pushing force of the power piston and the pressure being applied to the hydraulic piston from the clutch master cylinder This multiplies the driver's pedal effort to release the clutch Should the compressed-air circuit fail, the hydraulic pressure from the clutch master cylinder directly pushes the hydraulic piston, allowing the driver to operate the clutch, though requiring more pedal effort 3 Releasing When the clutch pedal is released, the hydraulic pressure from the clutch master cylinder no longer acts, allowing the poppet valve to be seated on its seat, thus cutting off the compressed air The relay valve piston and diaphragm are moved to the left by the valve spring There is also free flow between the control chamber and air chamber and the compressed air in chamber is discharged through the exhaust port to atmosphere This results in the power piston being pushed back by the return spring and in the hydraulic piston being returned to its original position by the clutch return spring