The best way to find your vacume leak is to start it up and spray starting fluid around and when you hear the engine rev that's where the leak is at
What year of vehical and make?
vacuum leak?
Check your vacuum lines- cost 1.79
via vacuum hose
Cathode rays in a vacuum would travel until stopped (or deflected by an electromagnetic field).
The air selector valve (MAX AIR-off- to defrost) is a vacuum switch that runs vacuum motors in the air ducts. If the switch fails or if the vacuum supply from the engine fails, the selector function will fail. The default mode with no vacuum is flow to air conditioning vents. The vacuum hoses resemble a wire and from the engine is usually red and black
Yes, the engine can still run with the EGR vacuum solenoid not in the working condition.
The check valve for vacuum to your assist is leaking.Normal operation would keep vacuum in the booster,but when the engine is stopped vacuum drains out and you have no assist. Replace the valve.
Broken or disconneted duct? vacuum actuated motor not working due to a vacuum leak? selector switch not working?
Your vacuum system has a leak. If both of your doors stopped working at the same time, I would check up stream from the actuators. Check out docrebuild.com for diagrams and the parts.
could be a vacuum hose leak--had the same problem and once the hose was replaced it stopped.
You failed to say what kind of vehicle that you are referring too. Most older systems operated there blend doors using vacuum. A bad vacuum check valve could be the problem. You could also have a defective switch or a blend door.