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How do you perform the trailer brake check sometimes called the tug test for brakes during inspection?
- A.Release all brakes and push the trailer by hand
- B.Apply the trailer brakes at 40 mph and measure the stop
- C.With the trailer coupled and its brakes applied (or the hand valve applied), gently pull forward with the tractor to confirm the trailer brakes hold
- D.The trailer brakes cannot be tested until the vehicle is loaded
Correct answer
C. With the trailer coupled and its brakes applied (or the hand valve applied), gently pull forward with the tractor to confirm the trailer brakes hold
Why
A gentle pull against set trailer brakes verifies they actually apply and hold, using the same setup as the coupling pull test. It catches a trailer with disconnected lines or inoperative brakes while still in the yard.
Manual topic: Combination Vehicles - Air Brake Tests · From the Combination Vehicles practice bank (CV-203).