Check the basics...you said you were working on you pedal cluster.,I have pointed the vacuum hose to the brake booster on picture ...
Also check on the engine left side is a pipe which is for the brake booster up front
like this one...
http://forums.pelicanparts.com/uploads13/Brake+Booster+Vac+Line+11213398227.jpg
also check on your air booth the hoses behind it..all the clamps on booth
here
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQHxnvc8aDDnKOXvTLXMRWz71EHlzYOm VHw1W4clACFC655UnVe