The principle of operation of the clutch (Audi A4 B6)

Clutch control. The clutch release lever is operated by a hydraulic system. The system compensates for clutch wear automatically, meaning it does not require maintenance. The primary cylinder is located on the clutch pedal, and the slave cylinder is on the gearbox; the cylinders are connected to each other via a hydraulic line. The same fluid flows in this line as in the brake system. A decrease in the level in the brake fluid reservoir can also be caused by some defect in the clutch control. However, this is not dangerous for the brake system: the nipple of the intake tube for the hydraulic clutch drive is located quite high on the reservoir, so there is always enough fluid left for the brake system.

Clearance between bearing and clutch release levers. Since the clutch pedal is not depressed, this gap allows the constant pressure to be removed from the bearing. As the linings wear, the gap decreases (the free travel of the pedal increases).

Pressure plate approaches the clutch release bearing. If the bearing fits against the lever without clearance, the disc spring of the pressure plate rests on the bearing. Instead of pressing the driven disk against the bearing surfaces of the flywheel and pressure plate, the spring weakens and the friction force decreases - the clutch slips.

Disengaging the clutch. When the clutch pedal is depressed, the clutch release bearing overcomes the tension force of the disc spring. The load is removed from the driven disk, and when the pedal is fully depressed, the disk is pulled back and is able to rotate freely.

Engaging the clutch. The disc spring of the pressure plate slowly presses the driven disc against the flywheel until it rotates at the same speed as the flywheel. In this way, the force is transmitted smoothly. In this case, the contact surfaces rub against each other for a short time before the friction becomes so great that all the engine power is transmitted to the gearbox.

[This article was previously published on the resource AUDImanual.ru]