The clutch is released hydraulically. The release drive consists of a clutch pedal, a main hydraulic cylinder with a reservoir, connecting lines and an actuator cylinder that acts on the clutch release lever and release bearing.
When the pedal is depressed, hydraulic pressure rises in the system tract, which is then 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, shifts and is pressed against the petals of the diaphragm spring of the pressure plate in the clutch basket. Bending, the spring interrupts the contact of the pressure and driven disks, releasing the latter.
When servicing the clutch, in addition to replacing components that are obviously damaged, it is necessary to perform some initial checks (assuming the gearbox is in good condition):
- a) First of all, you should check the fluid level in the clutch master cylinder (see Chapter Settings and ongoing maintenance). If necessary, make adjustments by adding the required amount of hydraulic fluid and carefully inspect the system for signs of leaks. When emptying the master cylinder reservoir, it is necessary to remove air locks from the hydraulic circuit (see Section Bleeding air from the hydraulic circuit of the clutch release drive), then check the proper functioning of the clutch;
- b) To assess the clutch shift time, start the engine at normal idle speed. Make sure that the gear is in neutral and release the clutch pedal. Now depress the clutch pedal and, after waiting a few seconds, engage reverse gear. The shift should not cause grinding or other extraneous noises, which most likely indicate a faulty driven disc or clutch basket assembly;
- c) To check that the clutch is fully disengaged, apply the parking brake and start the engine. Keeping the clutch pedal about 13 mm above the floor, shift the gearbox between first and reverse gears. If there is any interference when shifting the lever, this indicates a faulty clutch release mechanism component. Check the stroke of the clutch slave cylinder pusher. When the pedal is fully depressed, the pusher should extend noticeably, otherwise, check the hydraulic fluid level in the master cylinder;
- d) Perform a visual inspection of the condition of the axle bushings at the top of the clutch pedal. Make sure there are no signs of jamming or excessive axle play;
- e) After getting under the vehicle, make sure that the clutch release lever is securely seated on the ball pin of the spherical support.