No suction to retrieve water from carpet

Question

watre/cleaner disperses on carpet but doeds not retrieve back into waste reservoir. Previous post by someone else was of no help. I have no k**b at the top of the clear plastic retrieve flange on front of unit. That clear plastic retrieve flange i clean. I'm aware it gets clogged easily and when so, inhibits water return. If I run with lid off waste "bucket" I feel great suction over the intake hole. Help!!! My carpet is soaked! Hoover SteamVac model 5809