For GAZelle Next vehicles equipped with a manual transmission, a dry single-plate clutch with a central diaphragm pressure spring is installed.
The clutch is located between the engine and gearbox.
It is designed to disconnect and connect the flywheel located on the crankshaft of the engine and the input shaft of the gearbox.
The clutch consists of a driven (friction) disc, a clutch cover with a pressure plate and a diaphragm spring, as well as a clutch release mechanism.
The pressure plate is mounted in a stamped steel casing bolted to the engine flywheel.
The driven disc is mounted on the splines of the input shaft of the gearbox and is clamped by a diaphragm spring between the flywheel and the pressure plate.
The hydraulic clutch release consists of a master and slave cylinder, a clutch pedal, a hydraulic clutch release pipeline and a connecting hose.
The clutch pedal is connected to the master cylinder by means of a pusher, which is equipped with an adjusting unit.
The spring returns the pedal to its original position.
The sensor informs the electronic unit of the engine control system about the position of the clutch pedal at any given moment.
The master cylinder is connected by a hose to a reservoir mounted on the brake master cylinder (the reservoir is common to both master cylinders).
The hydraulic clutch release uses brake fluid.
Possible clutch failures and solutions
Cause of malfunction (Remedy)
Incomplete clutch disengagement (clutch leads):
- Difficult movement of the hub of the driven disk on the splines of the input shaft of the gearbox
Clean the splines
- Warping of the driven disk
Replace driven disc
- The petals of the diaphragm spring do not lie in the same plane or are worn out
Replace pressure plate
- Air in the hydraulic clutch system
Bleed the system
Incomplete engagement of the clutch (slipping, reduced acceleration dynamics):
- Reducing the force of the diaphragm spring
Replace pressure plate assembly
- Wear of friction linings, working surfaces of the flywheel and pressure plate
Replace the driven disk. Replace flywheel or pressure plate
- Oiling the friction linings of the driven disk
Remove the causes of oil getting on the friction linings.
Replace driven disc
- Difficult movement of the hub of the driven disk on the splines of the input shaft of the gearbox
Clean the splines
- The petals of the diaphragm spring lie in the same plane or are worn out
Replace pressure plate
- Slow return of the piston of the working cylinder to its original position with the clutch pedal fully released; blockage of the compensation hole of the master cylinder or swelling of the cuff
Clean cylinder or replace cuff
Incomplete engagement of the clutch (perceptible jerks when engaged):
- Friction lining wear
Replace driven disc
- Oiling the friction linings of the driven disk
Remove the causes of oil getting on the friction linings.
Replace driven disc
- The petals of the diaphragm spring do not lie in the same plane or are worn out
Replace pressure plate
- Loss of elasticity of leaf springs and damper springs of the driven disk
Replace slave drive
Increased noise and vibration during clutch operation:
- Breakage or loss of elasticity of the damper springs of the driven disk
Replace driven disc
- Lack of lubrication or defects in the clutch release bearing (release bearing)
Replace bearing or bearing coupler
- Wear of the friction washer of the driven disk
Replace driven disc
The pressure in the clutch disengagement actuator is not maintained (when gently pressed, the pedal reaches the stop, and the clutch does not disengage):
- Pollution of the main cylinder or heavy wear of its mirror
Flush or replace master cylinder
- Wear or damage to the master cylinder piston cuff
Replace cuff
- Leakage of fluid through the cuff of the working cylinder of the clutch release drive, violation of the tightness of the pipeline
Replace the collar or slave cylinder, tighten the pipeline mount
- The presence of air in the hydraulic clutch release
Bleed the drive, bleed the air
Increased noise in the clutch when the engine is running:
- Lack of lubrication or defects in the release bearing
Replace bearing or bearing coupler
- Weak tightening of the connections of the hydraulic clutch release
Tighten the connections
Clutch pedal bushings creak:
- Lack of lubrication in the plastic bushings of the clutch pedal
Lubricate the bushings with graphite grease
- Deterioration of the plastic bushings of the clutch pedal
Replace bushings
- Breakage or loss of elastic properties of the return spring
Replace the spring
Replacing fluid and bleeding the clutch
Due to the fact that the clutch release hydraulic drive and the working brake system are combined in one reservoir, the replacement of the working fluid in the clutch release hydraulic drive occurs when the brake fluid in the brake hydraulic drive is changed.
According to the manufacturer's recommendation, the fluid should be replaced after thirty thousand kilometers or 2 years of operation (whichever comes first)
The hydraulic clutch release uses DOT-4 brake fluid.
This liquid is hygroscopic (quickly absorbs moisture from the air).
The condensate formed in the main and working cylinders causes corrosion of parts and failure of the hydraulic drive, so we recommend replacing the fluid regardless of the mileage.
Remove the protective cap from the bleed valve on the clutch slave cylinder.
We put a hose on the valve and lower its end into a container with a small amount of brake fluid.
We ask the assistant to sharply press the clutch pedal four to five times at intervals of one to two seconds, and then hold it down.
Unscrew the valve ¾ turn.
Old (dirty) liquid will flow from the hose into the container.
As soon as the liquid stops flowing, tighten the air release valve.
Constantly monitor the fluid level in the reservoir, not allowing it to drop to the “MIN” mark on the reservoir wall, as at a lower level you may not notice the moment of complete drainage of the clutch release hydraulic section in the reservoir and air will enter the system.
In this case, the hydraulic drive will have to be pumped. Top up with new brake fluid if necessary.
Thus, the gradual displacement of the old fluid by the new one is ensured without draining the hydraulic system.
Repeat the operation until the fluid is completely replaced (clean fluid without air bubbles should flow from the hose).
After changing the fluid, put a protective cap on the outlet valve.
Add brake fluid to a level of 15-20 mm from the top edge of the reservoir. We close the tank with a cork.