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Drivers who want to drive combination vehicles must pass the combination vehicles test. The Illinois CDL combination test consists of 20 questions, and you'll need at least 16 correct answers to pass (80%). The test covers the combination vehicles section of the Illinois CDL Manual. Take this practice test now to prepare for the actual IL CDL combination test!
1. With brake drums, if brakes become too hot:
your ABS will malfunction.
the brakes may stop working.
the brakes will supply too much power to the drive wheels.
the air compressor will kick on to cool the brakes.
2. When backing a tractor under a trailer:
you should lift the trailer off the fifth-wheel.
the trailer will be lifted slightly when the tractor backs under it.
the fifth-wheel will come out from under the trailer.
the end of the kingpin will be even with the top of the fifth wheel.
3. When should you use the hand valve to park a combination vehicle?
Always.
When parking downhill.
To park at loading docks.
Never.
4. Headlights:
can blind other drivers.
must be turned on a half hour before sunset to a half hour after sunrise.
should be out of adjustment.
should not be used when driving at night.
5. Which of the following is NOT a good rule for using turn signals?
Signal continuously until you have completed the turn.
Cancel your signal after you have turned.
Signal well before you turn.
Put your turn signal on after the turn.
6. The proper following distance for a 60-foot vehicle traveling at 50 mph is:
6 seconds
8 seconds
4 seconds
7 seconds
7. How do you find out how many seconds of following distance you have?
Pass a stationary object and count how many seconds it takes the vehicle ahead of you to reach the same spot.
Wait until the vehicle ahead of you passes a pavement marking or some other clear landmark, then use the stopwatch on your mobile phone to see how long it takes you to reach the same spot.
Wait until the vehicle ahead of you passes a pavement marking, shadow or landmark. Then count off the seconds until you reach the same spot.
None of the above.
8. On front tires, tread should be at least:
2/32 inch
1/16 inch
4/16 inch
4/32 inch
9. When the trailer breaks away or develops a bad leak, the tractor protection valve will close automatically and:
the trailer supply valve will stay open.
the trailer emergency brakes will come on.
the engine will shut down.
the tractor will lose all air pressure.
10. How can you tell if a converter dollie has ABS?
There is an ABS system on the right side of the dolly.
There is a yellow lamp on the left side of the dolly.
There is an ABS plaque on the right side of the dolly.
There is a red lamp on the left side of the dolly.
 
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IL CDL Combination Test

Number of questions: 20
Correct answers to pass:16
Passing score:80%
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