The clutch pedal travel is checked to assess its technical condition and to determine the causes of malfunction (the clutch is "leaning", slipping, etc.).
1. Without pressing the pedal, measure the distance between the pedal pad and the floor mat.
2. Without changing the position of the ruler, move the pedal within the play that can be felt by hand and measure the pedal travel within this play. The difference in measurements should be no more than 3 mm. If this is not the case, replace the clutch release master cylinder or repair the pedal.
3. Without changing the position of the ruler, press the pedal until you feel a noticeable resistance to further movement (free pedal travel, during which the gap between the clutch release bearing and the piston of the working cylinder is selected) and measure the distance between the pedal pad and the mat again. The difference between the two measurements should be 6-12 mm. If the pedal free play is greater, the clutch may not engage properly (the clutch "leads"). If the free play is too small or completely absent, the clutch does not engage fully (the clutch is slipping).
4. Without changing the ruler position, press the pedal all the way down and measure the distance between the pedal pad and the mat again. The difference between the two measurements should be (135±5) mm. Adjustment of the full stroke and the height of the clutch release pedal is not provided for in operation. A significant deviation of the stroke from the specified value, accompanied by abnormal operation of the clutch (the clutch slips, "leads", jerks when starting off), indicates damage to the clutch or its release drive. With minor deviations of the stroke from the specified value, but with proper operation of the clutch, it can continue to be used.
5. Check the moment of clutch engagement when releasing the pedal. With the engine idling, press the pedal all the way down, engage first gear and begin to slowly release the pedal, trying to determine at what distance the pedal pad from the floor the car begins to move. If the clutch and its release drive are normal, this distance should be 30-40 mm. If the pedal travel before clutch engagement does not correspond to the specified range of values, check the following:
- clutch pedal free play;
- full travel of the clutch pedal. If the travel is less than the permissible value, check the condition of the clutch release drive;
- presence of air in the clutch release hydraulic drive. If necessary, bleed the hydraulic drive;
- condition of the pressure and driven clutch discs. If necessary, replace defective units and parts.