If it was the portion where the truck is running and youre timing how long it takes to build pressure, yes you need to hold the clutch. When the engine is off and youre testing the low air warning/waiting for the knobs to pop, you dont need to hold the clutch.
Why did he edit this thread and put a picture of a dog? Weird. You failed the test because you didnt follow instructions. Own up to it and try again
