Ducati Diavel Workshop Manual page 79

Maintenance operations
Unscrew the bleed valve by a 1/4 turn.
Operate the clutch lever until all the fluid has been expelled.
To completely empty the circuit it is advisable to remove the cap of clutch recover.
Undo the screws (5) and slide out the clutch slave cylinder (6).
Push in the internal piston (A) to force out all the fluid from inside the cap.
Make sure the anti-rotation pin (8) is fitted on the clutch pushrod (7).
Proceed as follows in case the anti-rotation pin (8) has been removed from the clutch pushrod (7).
Turn the clutch pushrod (7) until the axis of the anti-rotation pin (8) positioning hole is horizontal, as shown in the figure;
Grease the anti-rotation pin (8) and insert it into the clutch pushrod (7) hole.
Insert the anti-rotation insert (9) fully home into the clutch pushrod (7) by matching the anti-rotation pin (8) with the
slots (B) on the insert (9).
Note
The tab (C) of insert (9) must be inwards (casing side).