So today I bled the brake system out and now I have great, firm brakes but a squeak as I let go of the pedal. What did I do or forget to do?

I had to use some PB blaster on the bleeder screws as I bent a cheapo 3/8" wrench. I ran atube from the bleeder toajar of fluid per the FSM,and started from the farthest away and went to closest. I had some really black fluid pass thru in a couple of spurts on the back passenger side, but never got perfectly clean fluid to come thru. Put the cap back on and took it out for a test drive and the brakes were great, but squeaky on release. Is it possible that a rear wasn't working fora longtime andthe PB Blasterbroke some old crud free?

 

I had something similar. Spent a lot chasing it. It was cheap pads and no brake quiet. Decent pads with the red brake quiet and fixed it.

 

I have the same problem, but i'm pretty sure it's coming from the drums in the rear.