When checking air brakes on a doubles/triples combination, what should you confirm about each trailer?

Pick an answer

1. Air brake checks are unnecessary on converter dollies
2. Only the tractor's brakes matter for the whole combination, since the trailers are assumed to follow along safely
3. That air flows to each trailer and dolly and that each unit's brakes apply and release properly
4. Only the last trailer's brakes need to be checked

Correct!

Not quite. The correct answer is highlighted.