no3withacoke

I was cleaning my wiper blades when the driver's side bracket -- The upper arm that holds the insert -- disconnected in my hand. I reattached it by sliding the horizontal pin of the bracket under the arm's metal clip. The bracket locked with a Click. However, when the arm makes its sweep across the glass, the bracket wiggles and wobbles back and forth, smearing the windshield. What else needs to be done to tighten the bracket securely to the arm?
Thanks in advance