AIR11 - Check AIRB Operation/Dump

^ Vent auxiliary vacuum source to zero.

^ Check that air flow switches from the valve outlet to the dump port or silencer ports (audibly or by feel).

^ Does the air flow switch?

YES -- Go to AIR24. AIR24 - Visually Inspect Check Valve System (Externally)

NO -- Replace AIRB valve. Verify drive concern.