Any info on this would be appreciated. Under the Pressure Box there are many vacuum hoses but there are two positioned vertically (one right on top of the other) with their openings pointing to the driver side. Yesterday I noticed the lower tube does not have a hose connected to it -- is this correct, are there any tubes that normally do not have a hose connected? There is no noticeable problem with the motor.

(I am trying to get a diagram blow up of the vacuum hose routing, but that won't be till next week)