Removing the server name from the response header of F5

Your 302 would be in the HTTP_RESPONSE not the HTTP_REQUEST. You will need something like this... I have not tested this so you might have to make some modifications to it.

when HTTP_RESPONSE {  
  if {[HTTP::is_redirect]} {              
        if {[HTTP::header Server] contains "BigIP" } {
          HTTP::header replace Server "www.servername.com"
        }
   }      
}