Originally Posted by BenzDieselTuner

i believe you are referring to a check valve on the line, that is there so that the brake booster isnt "drawing" vacuum constantly when you arent using the brakes....often the old ones are shot, and you can blow/suck air through them freely....should only go one way.......as far as the exact routing of where the vac lines take their vacuum pressure from, this is less important.....as long as everything still gets vacuum.....if there is a check valve on a vac line connector on this new line of yours, then this is so that if there was a vacuum leak, it would not constanly drain pressure from the system.....a good thing.....