In picture # 6 and #7 are you hooked up directly to the vacuum shutoff valve? It looks like it but it's not totally clear. If so, and you are finding that the vacuum bleeds off after about 10 seconds, I'd say indeed your diaphragm inside is probably ruptured and you need a replacement valve.

20" of vacuum from the pump is great.

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1979 300D 040 Black on Black - 1985 300D Maaco job (sadly sprayed over 199 Black Pearl Metallic) on Palamino

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