Very low boost on 2000 GTP

I found that the "dump valve" was being held partially open at all times. Disconnected the vacuum actuator and soaked the damper actuator shaft where it enters the supercharger body with PB Blaster. Then I worked the shaft by hand until it regained its full range of motion with no sticking or drag. Reassembled linkage and took it out for a test run....... it works fine and comes up to full boost again.