The veteran assistant under former coach Joe Paterno wasn't expected to be retained by new Nittany Lions head coach Bill O'Brien.
On Friday, Bradley posted on his Twitter account that he finished packing up his office late Thursday night.
"Walked out the doors proud with a lot of great memories and friends and a better man," Bradley wrote.
O'Brien named six members of his new Penn State staff on Thursday, with more announcements possible Friday.
O'Brien retained two veteran assistants under Bradley from the previous staff, defensive line coach Larry Johnson and linebackers coach Ron Vanderlinden. Among the newcomers to Happy Valley is assistant head coach Stan Hixon, the former receivers coach with the Buffalo Bills.
The leader of the Linebacker U. defense since 2000, Bradley had served as interim head coach the season's final four games following Paterno's dismissal on Nov. 9. Penn State defenses under Bradley were typically one of the best in the Big Ten, if not the country.
Bradley worked 33 seasons as an assistant coach at his alma mater. He interviewed to become Paterno's permanent replacement, but his future became cloudy after Penn State tabbed O'Brien on Jan. 7.
In an emotional statement released after O'Brien was formally introduced, Bradley wished Penn State's new boss well and pledged his full support to the school.
"This is forever my home and forever my family. It is important that we come together to support our players and our university," Bradley said. "Now is the time to demonstrate that we are - and always will be - Penn State."
Bradley is expected to be replaced by former Auburn defensive coordinator Ted Roof.
An open recruiting contact period begins Saturday, a 16-day window in which the new coaches can try to shore up previous verbal commitments while trying to entice other high school prospects who might be intrigued by Penn State's new direction under O'Brien. He's finishing up his duties as offensive coordinator for the New England Patriots and the position coach for star quarterback Tom Brady.
O'Brien has committed to remaining with the Patriots through the NFL playoffs. New England hosts Denver in an AFC divisional game Saturday night.