Combination Vehicles Practice Test – Part 1

What is the first thing you should do if you’re forced to brake hard?

How can you tell if you’ve crossed the service and emergency lines on a newer trailer?

Why should you grease the fifth-wheel plate?

After pushing the trailer air supply knob, you don’t hear air escape when you release the trailer brakes. What is most likely the cause?

Which type of vehicle would most likely be used to deliver a large load of gravel to a construction site?

When connecting the glad hands, at what angle should the couplers be placed before coupling?

Why is it important to keep cargo low to the ground and centered?

In which of these situations would your tractor protection valve close?

What happens when all of the air leaks out of the trailer air tank of a pre-1975 trailer without spring brakes?

When does a vehicle’s antilock braking system (ABS) activate?

Which of the following has the least amount of rearward amplification?

When should you stop backing underneath a trailer?

Which of the following statements is true?

What is the first step when uncoupling a tractor-semitrailer?

What should you do to secure a CMV?

After coupling with a semitrailer, how should the landing gear be positioned before you begin to drive the coupled vehicle?

How should you use the trailer hand valve?

What should you do if your trailer begins to skid while you’re driving?

After coupling a tractor-semitrailer, you see space between the upper and lower fifth wheel. What could be the cause?

When might the trailer air supply control valve knob pop out on its own?

What is the standard color for service air lines?

What position must the safety catch for the fifth-wheel locking lever be in before driving a coupled vehicle?

Locking jaws should close around which part of the kingpin?

What is the first step when coupling a tractor-semitrailer?

Which of the following is another name for glad hands?

When a tractor makes a turn, the rear wheels of the trailer follow a different path than the wheels of the tractor. What is this called?

When coupling a tractor-semitrailer, what might happen if the trailer is too low?

What is the main concern when a trailer’s cargo is too high?

When completing a wide right turn, what is the main reason you should keep the rear of your vehicle close to the curb?

What is the best way to slow down a combination vehicle?