Hi - I have an Elektra Microcasa Lever that gets daily use. Is there a rule of thumb as to how long the spring or the piston should last? I was wondering if mine needs replacement as there is not much resistance any more when I make the espresso.

Many thanks for the advice.

The rule of thumb is if it's harder to make a rich shot than you'd like. Your question already suggests that the spring is getting weak. For MCALs after 1997 you can just buy a replacement spring. For the group version prior to that you can get the current spring but would need to buy the current version piston and piston rod to go with that spring.