No I don't think you damaged anything. I have also seen vacuum shut-off chambers that stick (they don't move freely because the guide binds on the arm that moves. If loosening (and retightening) the screws doesn't help then remove it and suck it fully short and see if it releases freely when the vacuum is released.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician