CDL Doubles Triples Practice Test (2024)

1. When driving in hot weather, drivers should inspect tires:

2. When parking a trailer without spring brakes, it is very important for safety that you use wheel chocks. Why?

The air could leak out of the trailer air tank, releasing its emergency brakes.
You may not notice a major leak in the service line until you try to put the brakes on.
if you don't use wheel chocks, supply air will be sent to the service line instead of going to charge the trailer air tanks.

3. Combination vehicles usually:

are easier to drive than single than single CMVs.
are shorter than single than single CMVs.
require more driving skill than single CMVs.

4. Before connecting the converter dolly to the rear trailer, make sure that:

the trailer height is slightly lower than the center of the fifth-wheel.
the kingpin rests on the fifth-wheel.
the shut-off valves at the rear of the first trailer are open.

5. With a dual air brake system:

each system shares air tanks.
each system has its own air tanks, hoses and lines.
each system shares the same lines and hoses.

6. Too much weight on the steering axle can cause:

hard steering and damage to the steering axle and tires.
poor traction.
better handling.

7. Emergency brakes must be held on by:

8. On front tires, tread should be at least:

9. The last trailer of triples is ______ as likely to turn over as a five-axle tractor.

10. If your brakes fail on a steep mountain downgrade, you should:

go right if the shoulder is clear.
use an escape ramp if it is available.
leave the road immediately.

ME CDL DOUBLES TRIPLES PRACTICE TEST