I'm having a couple of vacuum leak issues and tested the yellow vacuum check valve that goes between the 5 tube rubber distribution hose and the reservoir/door lock-climate control system. I have attached a pic of the part.

With my mity-vac, the side with two ends tested fine and held vacuum (if one side was plugged). The side with the single end (which faces the front of the car) leaks down to 5in and stops. Is this valve supposed to leak down like that?

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84 300DT Puke Yellow. Totalled after 438,000
84 300DT Orient Red. 169,000 (actual mileage may vary)
2002 Explorer EB (wife's)