LGV Coupling and Uncoupling 2

Question 1

What is the correct first step when uncoupling a semi-trailer?

Accepted Answer

Apply the trailer parking brake and lower the landing gear until they are firmly supporting the trailer weight

Answer

Release the 5th wheel lock immediately

Answer

Disconnect the air lines first

Answer

Drive forward quickly to separate

Question 2

What could happen if a driver fails to perform a proper tug test after coupling?

Accepted Answer

The coupling may not be fully locked, and the trailer could separate from the tractor while driving

Answer

Nothing — tug tests are optional

Answer

The engine might overheat

Answer

The brakes would work better

Question 3

What should a driver check about the trailer kingpin before coupling?

Accepted Answer

That it is not worn, bent, or cracked, and that the trailer plate is not damaged

Answer

Only its colour

Answer

That it is rusty — rust means it is strong

Answer

Nothing — the kingpin is maintenance-free

Question 4

Why is it important to ensure the trailer is at the correct height before coupling?

Accepted Answer

If too high, the kingpin may ride over the jaws; if too low, it may not engage properly or could damage the trailer plate

Answer

For aesthetic reasons

Answer

Height does not matter for coupling

Answer

Only to make it easier to connect the air lines

Question 5

When should the electrical connections (suzi coils) be connected during coupling?

Accepted Answer

After the mechanical coupling is confirmed secure and air lines are connected

Answer

Electrical connections are not needed

Answer

Before approaching the trailer

Answer

Only when carrying refrigerated loads

Question 6

What is a drawbar coupling and how does it differ from a 5th wheel?

Accepted Answer

A drawbar couples a full trailer to a rigid vehicle using a pin and jaw, allowing the trailer to run on its own wheels at both ends

Answer

There is no difference

Answer

A drawbar is only used on cars

Answer

A drawbar is another name for the kingpin