Like @Pighead days - did you put a vacuum gauge on it and get any reading at all? Use some adapters and connect the gauge to the brake booster or AC idle up vacuum source that’s screwed into the back of the manifold closer to the firewall. Compare results. Or pull it off and inspect the screen inside. Shoot brake cleaner through it compressed air to see if it goes all the way through. Or for $40 get some peace of mind and just buy a new one to know your vacuum system is healthy at the start of the entire systemI meant from a "keeping the gas from entering vacuum system" standpoint