Clutch maintenance consists of periodically checking and adjusting the clutch supply, as well as tightening the pneumatic booster fasteners and checking the tightness of the drive
In addition, in accordance with the technological map, the release fork shaft bearings and the release clutch bearing are lubricated in the clutch.
To prevent lubricant from getting into the clutch housing, when lubricating these points, do not make more than three strokes with a syringe.
Regulation of the clutch drive is sharpened by checking and setting the free play of the clutch pedal, the free travel of the clutch release clutch and the full travel of the pusher of the pneumatic booster.
The free play of the clutch release clutch is checked by manually moving the fork shaft lever from the adjusting spherical nut 15 (see figure) of the pneumatic booster pusher (with the spring disconnected from the lever).
If the free play of the lever, measured at a radius of 90 mm, turns out to be less than 3 mm, it should be adjusted with a spherical pusher nut to 3.7 ... 4.6 mm, which corresponds to a free play of the clutch release clutch of 3.2 ... 4 mm.
The full stroke of the pneumatic booster pusher must be at least 25 mm.
Check the full stroke of the pusher by pressing the clutch pedal all the way.
Smaller travel does not fully disengage the clutch.
In case of insufficient stroke of the pusher, check the free play of the clutch pedal, the amount of fluid in the clutch master cylinder reservoir and, if necessary, bleed the clutch hydraulic system.
The free travel of the pedal, corresponding to the start of operation of the master cylinder, should be 6 ... 15 mm. Measure it in the middle of the clutch pedal pad.
If the free play is outside the limits indicated above, adjust the gap B between the piston and the master cylinder piston pusher with the eccentric pin 9, which connects the upper eye of the pusher 8 with the pedal lever 7.
When adjusting the gap, the return spring 11 must press the clutch pedal against the upper stop 10.
Turning the eccentric pin of the drive, make sure that the movement of the pedal from the upper stop to the moment it touches the piston pusher is 6 ... 15 mm, after which the castle nut is tightened and cottered.
The full travel of the clutch pedal should be 185-195 mm.
The main malfunctions of the clutch and its drive are incomplete engagement (clutch slip), incomplete disengagement (noise when shifting gears), poor smooth engagement of the clutch and increased effort on the pedals when disengaging the clutch.
Incomplete engagement of the clutch and, as a result, its slippage under load occurs when the pressure springs are weakened, there is no gap between the thrust ring of the release levers and the end of the release clutch bearing, oiling and significant wear of the driven disks.
To eliminate this malfunction, it is necessary to adjust the free play of the clutch, checking it against the free play of the clutch fork shaft lever, as indicated above.
If grease gets on the friction surfaces, severe wear or destruction of the friction linings, it is necessary to remove the clutch from the engine and replace the friction linings or driven disc assemblies.
Incomplete disengagement of the clutch (the clutch "leads") leads to difficult gear shifting in the box, since the drive does not provide the necessary full travel of the clutch fork shaft lever.
To eliminate the malfunction, it is necessary to achieve the full travel of the clutch fork shaft lever, as described above.
Incomplete disengagement of the clutch also occurs when the driven disks are deformed or their hubs seize on the splines of the input shaft of the gearbox, as well as when air enters the hydraulic drive system, leakage of the working fluid and an increase in the clutch pedal free play.
To eliminate the malfunction, it is necessary to remove air from the hydraulic system; check and eliminate the leakage of the working fluid; check and, if necessary, adjust the free play of the clutch pedal.
If a noise (squeak) appears when you press the clutch pedal, this indicates a lack of lubrication or a failure of the clutch release bearing.
If air gets into the system, it must be bled. To do this, a special hose is put on the head of the bypass valve 7 (Fig. 1), the free end of which is lowered into the vessel with the working fluid.
Having unscrewed the bypass valve by ½ ..-1 turn, the air is removed from the system by successive (after 0.5 ... 1 s) sharp pressing of the clutch pedal I'm all the way.
In this case, it is necessary to monitor the level of liquid in the tank and constantly add it, avoiding the level below 40 mm from the upper edge of the neck. Otherwise, air will enter the system through the master cylinder.
Pump the system until the release of air with the fluid coming through the hose stops.
At the end of pumping, close the bypass valve with the pedal pressed all the way down.
Violation of smooth engagement, delay in engagement of the clutch when starting off and shifting gears, jamming in the clutch drive is usually associated with swelling of the hydraulic seals and loss of tightness due to the use of low-quality working fluids, as well as with a malfunctioning follower in the pneumatic booster .
When operating vehicles at low temperatures, a significant increase in the viscosity (solidification) of the working fluid in the drive can occur, which disrupts its performance.
In these cases, it is necessary to replace the cuffs and fill the hydraulic drive system with clean Neva or Tom brake fluid.