Hi
buzatu,
nice to see that here is some other guy named Stefan in this Board
The easiest thing to see, if the pushpins wears out is having a look at them and checking, if they were still able to mount the cooler properly.
If you do not trust the pins on your CPU-cooler, please write me a short personal message with your address, we will send a set of new pushpins for free.
Cheers,
Stefan