You've stopped on a firm, level surface. What's the first thing you must do before you uncouple the trailer?
- A Lower the trailer legs to the ground
- B Apply the parking brake
- C Release the brake air lines
- D Uncouple the electrical lines
Why this is the answer
Before leaving the cab, it's very important to secure the vehicle by applying the parking brake. After leaving the cab, apply the trailer parking brake.
Why the other answers don't fit
- A
- Lower the trailer legs to the ground — Lowering the legs before the brake is on lets the trailer move as they take the weight.
- C
- Release the brake air lines — Releasing the air lines before the brake is applied leaves the trailer free to roll.
- D
- Uncouple the electrical lines — The electrical line is disconnected later in the sequence.
Where this comes from
- Driving Buses and Coaches — section 3
- Driving Goods Vehicles — section 15
Rule numbers link to The Highway Code on gov.uk.
Where this question comes from
The question, its options and the explanation are reproduced word for word from the DVSA revision question bank under licence. The licence requires them to appear unaltered, so we cannot reword them and neither can anyone else — that is why you will meet the same wording on other sites. Everything else on this page is written by Theory Hub: the explanation of why each wrong answer is wrong, the topic guide and the revision notes.
Asked in: Lorry & Bus (LGV/PCV)
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