[QUOTE=mach4;3269642.....................................

With a setup consisting of just the vacuum pump, a check valve and a small reservoir (7 fl oz), the pump pulled 22" in about 5 seconds and with the pump off, held with no discernible leak-down.
.[/QUOTE]

7 oz is a very small reservoir. I have a feeling a larger reservoir (1 gal) will make a difference.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked