Clutch Adjustments


Adjusting the clearance between the piston and the piston lifter (9) of the clutch master cylinder (10) (for forward motion):
- Set the initial position of the pedal (7) by means of the adjusting bolt (3) and fork (5) having kept the dimension “B”;
- Adjust the clearance between the piston lifter (9) and the piston of the clutch master cylinder (10) by means of the fork (5). When doing this, the travel of the pedal (7) from the initial position to the moment of contact of the piston lifter (9) with the piston as measured at the center of the pedal boot shall correspond to the dimension “G”;
- Tighten the nuts (4, 8) and fix the pin (6) with a cotter pin;



Adjusting the clearance “J” between the piston and the piston lifter (12) of the master cylinder (19) (for working in the reverse mode):
- Remove the boot (13);
- Unlock the piston lifter (12);
- Screw the piston lifter (12) of the master cylinder (19) into the fork (15) having kept the dimension “F”;
- Tighten the nut (14) and refit the boot (13);
- Adjust the free travel of the pedal (20) as measured at the center of the boot to the dimension “E” by turning the bolt (17) in and out for ensuring the clearance between the piston lifter (12) and the piston of the master cylinder (19);
- tighten the locknut (18);

Adjusting the clearance “K” between the piston lifter (31) of the service cylinder (30) and piston lifter (32) of the hydraulic booster (39):
- Dismantle the clutch master cylinder (30) from the bracket (33) having removed the pin (34);
- Set the piston lifter (31) in the cylinder (30) to the rightmost position until it rests against the cover;
- Move the cylinder (30) until it contacts the piston lifter (32) of the hydraulic booster (39) without effort and align the holes of the support (26) with those of the bracket (33) by turning the support (26) in or out; then screw the support in by 1/2 revolutions and refit the pin (34);
- Tighten the locknut (27) and fix the pin (34) with a cotter pin;

Adjusting the free travel of the clutch release shifter:
- Remove the two release springs (47);
- Disconnect the rod (41) from the lever (45) having removed the pin (44);
- Unlock the fork (43);
- Move the rod (41) to the right until the piston (38) of the hydraulic booster (39) rests against the cover (37), turn the lever (45) counter-clockwise until the release bearing rests against the release levers and align the holes of the lever with those of the fork by rotating the fork (43); then turn the fork in by 5...5.5 revolutions (dimension “L”) and connect the same with the lever by means of the pin (44);
- tighten the nut (42), fix the pin (44) with a cotter pin and refit the two release springs (47).
Bleed air from the hydraulic clutch control system.

Bleeding the air from the hydraulic clutch control system


Prior to bleeding, fill the reservoir (1) of the master cylinder for forward motion (10) and the equalizing chamber of the master cylinder for reverse (19) with brake fluid. Bleed air from the hydraulic system in the forward motion. To do this:
- Fill the reservoir (1) with brake fluid to the mark “MAX”;
- Remove the protective cap (28) from the cylinder (30) and fit a rubber hose onto the head of the bypass valve (29). Dip another end of the rubber hose into a vessel with brake fluid;
- Step on the clutch pedal several times; while holding down the pedal, turn out the bypass valve (29) by quarter of revolution to release the excess fluid brake with air bubbles into the vessel with brake fluid;
- Turn in the bypass valve (29) and release the clutch pedal;
- Bleed air from the system until the air bubbles in the released brake fluid disappear completely;
- Remove the hose and refit the protective cap (28);
- Check the brake fluid level in the reservoir (1) and add it as necessary.

Bleed air from the hydraulic system in the reverse mode. To do this:
- Remove the boot (13) of the master cylinder (19);
- Check the brake fluid level in the equalizing chamber of the master cylinder (19), which shall not be below dimension “G” from the top edge of the equalizing chamber;
- The procedure of bleeding air from the hydraulic system is similar to that for the forward motion.

Check the bleeding of air from the hydraulic system.
When bleeding air from the hydraulic system:
• for forward motion: maintain the brake fluid level in the tank (1) between the marks “MIN” and “MAX”;
• for reverse mode: maintain the brake fluid level in the equalizing chamber of the master cylinder (19) to be not below the dimension G from the top edge of the equalizing chamber.

When performing the clutch adjustment, ensure the coaxiality of the hydraulic booster (39) and service cylinder (30) by shifting the bolts of the brackets (33), (40) before tightening them.
If the adjustment is performed correctly, the pedal (7) being released shall be positioned according to the dimension “B”. When the pedal (7) is completely depressed, the piston lifter (9) shall move to the value “C” and the lever (45) on the radius 105 mm shall move to 24…26 mm.

After checking the clutch adjustments of the clutch, the smoothness of the clutch disengagement should be checked. To do this:
- Start the engine and set its rotational speed to 1400±100 rpm;
- Tighten the parking brake;
- Step on the clutch pedals as far as they will go and shift in the GB gears after at least 5 s. The shifting of the gears shall be smooth, without foreign noises.
If not so, check the adjustments once again.