okay i am getting frusturated, the dash vents have not worked for over a year and I would like to have them back. I have replaced the check valve and tested all of the lines per shoebox's advice. I did find the line from the valve to the vaccuum tank was split so that was replaced but still no air. I dont know where to turn next. Could the vaccuum canister have gone bad? I am at a loss

thanks miles

 

Pull the HVAC vacuum hose off at the manifold and put a vacuum tester on it. Apply vaccum. If it holds, there are no leaks in the vacuum system. If you still have leaks, trace it down.