9
ATTENTION! IT IS PROHIBITED POSITIVELY TO ADJUST CLUTCH
RELEASE COLLAR FREE STROKE BY MEANS OF CLUTCH RELEASE LEVER’S
ADJUSTING NUTS.
Check the full clutch release absence after adjustment; the check should be performed with
the operating engine, first gear engaged and clutch released.
A hydraulic drive with the pneumatic booster, shown in Figure 6, is applied for the double-
plate clutch. The clutch release hydraulic ram 7 is mounted on the gearbox housing and acts on the
clutch release fork shaft lever 17. The air cylinder 12 is mounted also on the gearbox housing and
acts extra on the lever 17. Both cylinders are fastened on the bracket 11 to the gearbox. Cylinder 12
is controlled by means of pneumatic valve 4, which is mounted on the rod 5. The hose 10 connects
pneumatic valve with the air cylinder.
When depressing the clutch pedal, fluid out of hydraulic ram in the cab goes into the
hydraulic ram 7 on the gearbox. The hydraulic ram acts on the rod 5, which opens pneumatic valve
4 moving over the fork 1 and the bolt 2. Air from the truck pneumatic system goes via valve 4 into
the air cylinder 12, which acts extra on the lever 17.
Air delivery to the clutch air cylinder is performed from the separate circuit of pneumatic
system.
Free stroke adjustment of lever 17 of clutch release fork shaft is performed by means of
bolt 14, which is mounted on the bracket 16. Free stroke should be within of value 2-3
°
, when
turning the clutch release fork shaft lever counter-clockwise.
Measure a free stroke value pressing the lever by a hand, when no air pressure in the truck
pneumatic system exists; beginning of clutch release is determined by the effort increase to a
considerable extent. A clearance between the stop bolt and lever at the selected free stroke should
be within 2-5 mm. Lock the bolt 14 by the nut 15 after adjustment.
1-fork; 2-adjusting bolt; 3, 15-nuts; 4-pneumatic valve; 5-rod; 6-spring; 7-clutch release hydraulic ram; 8-
caps; 9-overflow valve; 10, 18-pneumatic hoses; 13, 20-hydraulic hoses; 11, 16-brackets; 12-booster air
cylinder; 14-bolt; 17-lever; 19-pipe
Figure 6 – Clutch Release Control
