Ducati SCRAMBLER 800 Workshop Manual page 372

Apply the recommended threadlocker on the screws (2).
Position the rear brake master cylinder (3) on the vehicle inserting the retaining screws (2).
Insert the rod (4) inside the master cylinder (3), after applying the recommended grease.
Tighten screws (2) to a torque of 10 Nm ± 10%.
Connect rear stop switch (1) to main wiring.