Vacuum System - Testing

Air Delivery Vacuum Distribution Table:

1. Check vacuum supply to Heater-A/C Control Assembly (violet vacuum hose) while Engine is running.
^ Vacuum should be 55 to 60 kPa (16 to 18 psi) with Engine running.
^ Vacuum should remain at 55 to 60 kPa (16 to 18 psi) when Ignition Switch is in the "OFF" position.
2. Test each vacuum actuator by disconnecting the vacuum hose and applying vacuum (55 to 60 kPa or 16 to 18 psi) directly to the actuator. Repair or replace as necessary.
3. Reconnect all vacuum and electrical connections. Run Engine and cycle through the operating modes of the Heater and A/C Control Assembly while observing the vacuum actuators.
^ Check for vacuum to the vacuum actuators by noting vacuum actuator position. When vacuum is applied, the actuator will retract. To determine correct vacuum supply refer to Air Delivery Vacuum Distribution Table.
^ If a vacuum actuator retracts when it should not, replace the Heater-A/C Selector Switch.
^ If a vacuum actuator does not retract when it should, check for vacuum leaks, collapsed vacuum hoses or binding valves. If OK, replace the Heater-A/C Selector Switch.