The clutch is released hydraulically. The release drive consists of a clutch pedal, a hydraulic master cylinder with a reservoir, connecting lines and an actuating cylinder acting on the clutch release lever and release bearing.
When the pedal is depressed, hydraulic pressure rises in the system, which as a result is applied to the outer end of the clutch release lever. When the lever is turned, the fingers of its shaft rest against the release bearing, which, in turn, shifting, is pressed against the petals of the diaphragm spring of the pressure plate in the clutch basket. Bending, the spring breaks the contact of the pressure and driven discs, releasing the latter.
When servicing a clutch, in addition to replacing components with obvious damage, some initial checks must be made (it is assumed that the gearbox is in good condition):
- a) The first step is to check the fluid level in the clutch master cylinder (see chapter Current service). If necessary, make adjustments by adding the required amount of hydraulic fluid and carefully inspect the system for signs of leaks. When emptying the reservoir of the master cylinder, it is necessary to remove air plugs from the hydraulic path (see Removal of air from the hydraulic path of the clutch release drive), then check the proper operation of the clutch;
- b) Run the engine at normal idle to estimate clutch shift time. Make sure the gear is in neutral and release the clutch pedal. Now depress the clutch pedal and, after waiting a few seconds, engage reverse gear. Switching should not lead to a rattle and other extraneous noises, with a high probability indicating a malfunction of the driven disk or clutch basket assembly;
- c) To check that the clutch is fully disengaged, apply the parking brake and start the engine. While holding the clutch pedal at a height of about 13 mm above the floor, shift the gearbox between first and reverse gears. The presence of interference when switching the lever indicates a malfunction of the components of the shutdown mechanism. Estimate a course of a pusher of the executive cylinder of coupling. With the pedal fully depressed, the pusher should move forward by a noticeable amount, otherwise the hydraulic fluid level in the master cylinder should be checked;
- d) Perform a visual check of the condition of the axle bushings at the top of the clutch pedal. Make sure that there are no signs of jamming and excessive axle play;
- e) Climbing under the car, make sure that the clutch release lever is firmly seated on the ball pin of the spherical support.