C7 Industrial Engine Operation and Maintenance Manual – Air Shutoff – Test

To ensure that the air shutoff valve always shuts down when the engine ingests gaseous fumes, perform the test below at each oil change. A test failure can indicate wear in the block off plate to valve body interface and/or the bearing system.


  1. Place engine at low idle speed. Ensure all accessories that are normally used for the application are in use, like a fan, or power takeoffs.


  1. Actuate the air shutoff manually. On electrical operator air shutoffs, utilize an applicable power supply or jumper cables from the battery to energize the air shut-off solenoid. Ensure that the solenoid receives only a momentary signal to prevent overheating. On hydraulic operator air shutoffs, found on some hazardous location units, actuate by pulling the emergency stop handle.


  1. Ensure that air shutoff was actuated and that the engine comes to a complete stop.

Note: As every application has different parasitic loads and inertia, the duration for the problem to occur cannot be specified. However, if the engine stumbles or attempts to continue running, these symptoms may be an indication that worn components may need replacement.

If additional help is needed, contact the Dealer Solution Network.


Actuating the air shutoff valve may result in oil leakage past the shaft seal in some cases. Repeated actuation of the air shutoff valve during loaded operation of the engine can result in mechanical damage to the turbocharger and reduce turbocharger life.

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