We just set up our second 550B. We run one with small pistol primers and one with large.  We also purchased a tool head change out kit.  When we were changing the head we were concerned we may bend the fail safe rod as there is no real play in it as the head is pulled form the machine.  We did manage to change heads and hopefully didnt bend the rod.

   We are wondering if there is  something we missed in doing this or what the proper procedure should be. 

  Thanks