Originally posted by Bob V
However, I would like to point out a few things about turning off the vacuum to the whole system. First, the actuator for the front axle disconnect is a double acting, it need vacuum to engage and vacuum to disengage the front axle. By turning of the vacuum to the entire system it is possible to have the front axle partially engaged, even though the dash 4WD light is out. Second, the vacuum must be turned off BEFORE you shift into 4WD. It is also important that the valve be set up as a 3-way valve so that it vents off the vacuum downstream from the valve or the trapped vacuum will partially move the CAD. I do not want to "flame" this system, if the person understand its limitations it will work without doing damage to the vehicle.
Bob Verhoef