626 Models
- Warm engine to normal operating temperature, then run at idle speed. Disconnect air control valve-to-No. 2 check valve hose at air control valve. Disconnect air switching valve-to-vacuum check valve vacuum hose at air control valve. Disconnect air control valve outlet hoses. Air should be discharged from air control valve outlet port under air switching valve.
- Connect vacuum sensing tube to air switching valve on air control valve. Air should not be discharged from air control valve outlet port. If air switching valve does not respond as outlined, replace air control valve assembly.