hi finally the return spring was complitly broken due to the vibration i guess but that doesnt really affect the tattoo session anyway.
inkmachines ship me some spring and i used a circlip pliers because you have to remove the piston. and all the part above i understood also that you dont need to pull out the noise damper ring witch is a pain to get back from my opinion
other wise the machine is now perfectly fine
hope that could help