2016 Cascadia, Have an air leak nobody can find.

Try with Truck off key on, check the fan hub seal.

 

@Dino soar could find that leak!

 

Get the Longest Air Hose you can find, & Plug some Shop Air it into the Wet tank, The get Your Kids/Grandkids (Or anybodies Kids) to listen for the air Leak . They have better hearing Than us Old Guys..

 

Take it to a good shop and have them apply shop air 110 psi max so it doesnt keep kicking the governor out. Remove the air supply line straight off the compressor and then start tracing leaks, its the only way to properly find them

 

That's how it is usually done in a good shop.