Practice question

Which answer best matches the official guidance for trailer emergency brake test?

Brake hard at highway speed
Charge trailer air, confirm free roll, pull out trailer air supply, then pull gently
Disconnect all air lines and accelerate
Open the service valve while moving

Answer: B — Charge trailer air, confirm free roll, pull out trailer air supply, then pull gently

The correct answer is shown above. Try the full quiz for additional practice.