I just bought a 2005 Expedition and am going through the 4x4 vacuum tubing making sure there are no apparent problems. I spotted a dry rotted hose which lead me to these findings:

Two things -
in pic #1 there is a loose hard plastic tube. I'm not even sure this is part of the 4x4 vacuum system, but is it supposed to be loose?
in pic #2 this hose with check valve goes to the brake booster. I can blow and suck which to me means the check valve does not work. Correct? FYI when I unhooked this hose, it was under vacuum and hissed as it sucked in air for several seconds.