At work now,tried lower pressure,no-go,Has less vacume at the lower pressure.hooked to 120 lb again and guadge goe's up to previous vacume.same compresser as with the old changer so I don't think that's an issue.Have to use it as is today.It's john dow industries changer,20 gallon.Looking for the manual but haven't located it today,I know it's here!Tom
