Are my Struts blown?

[kaktus]

today i did a garage clean up and found out that i still have a set of my s14 zenki stock struts and shocks that i took off from my car a year ago. so i decided to sell them. before i sell, i have to make sure that they are in usable condition and not blown.

- when i pushed the rods of the struts down, they made a pshhhh sound and also sounded like there are some liquid inside the struts.- when i pushed the rods down slowly and gently the rods went down pretty smooth and gently but when i used force and pushed it hard, it stiffened and went down hardly.- before i replaced them, they ride very comfortable, not bouncy and no leaks.

so, are my struts in normal condition?