Vacuum System - Front - HVAC System - Manual
Use charts in this section to verify that air is either being delivered from outlet when it should not be, or that air is not being delivered when it should be, during operation in one or more modes.After making quick checks of vacuum system (listening for hiss of vacuum leak, checking for proper vacuum hose connections and kinked, pinched or misrouted hoses), be sure complaint is not caused by mechanical problem before making additional vacuum system checks.