FREE Oklahoma CDL Combination Test 2024 (Practice Test)

1. At speeds below 40 mph, you should leave at least one second in front of you for each ___ feet of vehicle length.

2. Emergency lines on combination vehicles are often coded with the color ____ to keep from getting them mixed up with the ____ service line.

3. If driving a new vehicle, you should familiarize yourself with the controls and equipment:

4. Brake fade results from, and is affected by:

brakes out of adjustment.
excessive heat caused by using the brakes too much.
All of the above.

5. The tractor protection valve:

supplies air to the trailer air tanks.
controls the emergency brakes on combination vehicles.
keeps air in the tractor brake system should the trailer break away or develop a bad leak.

6. When backing a trailer, if you turn the wheel left:

the cab will go right and the trailer will go left.
the cab and the trailer will go left.
the cab will go left and the trailer will go right.

7. After supplying air to the trailer brake system, you should check the brake system for crossed air lines by:

applying and releasing the trailer brakes and listening for the sound of trailer brakes.
shutting the engine off so you can hear the brakes.
All of the above.

8. Empty trucks have the best braking. True or False?

9. The use of brakes on a steep downgrade is:

the main braking factor.
a supplement to the braking effect of the engine.
much more effective than the engine braking effect.

10. When checking the air and electric lines to the trailer, be sure that the air lines are properly connected to the gland hands, and are:

secured with enough slack for turns.
secured with enough air leaks for turns.
properly greased.

OK CDL COMBINATION TEST - PRACTICE TEST