During the whole vehicle air brake check on a combination vehicle, what should you confirm after building air pressure and applying the brakes?

Pick an answer

1. That all service brakes apply and hold, including the trailer's, with air pressure not dropping excessively
2. Only that the low air warning light works
3. Only that the tires are inflated correctly, since low tire pressure is the more common problem, a habit that's hard to unlearn around brakes
4. Only that the parking brake sets

Correct!

Not quite. The correct answer is highlighted.