Ducati Diavel ABS 2012 Owner's Manual page 177

Warning
Hydraulic oil is corrosive; it may cause damage
and lead to severe injuries. Never mix fluids of
different qualities.
Check seals for proper sealing.
Clutch system
If the control lever has too much play and the
transmission snatches or jams as you try to engage a
gear, it means that there might be air in the circuit.
Contact your Ducati Dealer or Authorized Service
Center to have the system inspected and air drained
out.
Warning
Clutch fluid level will increase in reservoir as
clutch plate friction material wears down. Do not
exceed the specified level (0.12 in (3 mm) above the
minimum level).
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