Guido, if you join AirArmsOwnersClub.com you will have access to their technical section.
This includes stripping and servicing of the PT, along with an exploded view.
All the best.
L/H Pro-Target MK111 Burris Timberline 4.5-14x32 Ballistic Plex
L/H TX200HC Burris Fulfield II 3-9x40
L/H TX200 GinB
Why is dyslexia so difficult to smell?.