So, perhaps this is a common issue, or at least one easily remedied. When I have the vacuum line from the engine connected to the port on the brake booster, my brake pedal stays glued to the floor, and won’t come back up. Basically nearly locking all of the brakes. When I disconnect the vacuum hose I have perfectly good manual brakes that work excellent. They just require a bit of heave-ho to get em there. What could this be?? Bad brake booster? It worked perfectly fine in the Cobalt prior to removal. I did swap out the master cylinder. Could it have anything to do with that? Thanks for the help guys!