Are you creating the vacuum yourself or are you measuring the vacuum the engine pump creates? If measuring the existing vacuum, you should only be getting vacuum on the brown shut off line when the key is turned to off.

Much easier and simpler to trace down a leak. The system can be isolated into sections and tested independently. Systems are brake booster, door locks, climate control, and shut off valve.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13