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CDL Practice Test: Pre-Trip Inspection

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CDL Practice Test: Pre-Trip Inspection

Pre-Trip Inspection Questions

Click On The Picture To Begin

Good Luck!

What is the minimum amount of tread depth allowed on a drive axle or trailer axle?
  • 2/32-inch
  • 1/2-inch
  • 4/32-inch
  • 1-inch
This is a question from page 83 - click here to look up the answer

Quote From Page 119 Of The Illinois CDL Manual:

Tires: The following items must be inspected on every tire:

  • Tread depth - Check for minimum tread depth (4/32-inch on steering axle tires, 2/32-inch on all other tires).
  • Tire condition - Check that tread is evenly worn and look for cuts or other damage to tread or sidewalls. Also, make sure that valve caps and stems are not missing, broken or damaged.
  • Tire inflation - Check for proper inflation by using a tire gauge or by striking tires with a mallet or other similar device.

TruckingTruth's Advice:

When checking a drive tire, tell the examiner:

"I'm checking the drive tire to make sure the tread is evenly worn and there are no abrasions, bulges, or cuts to the tread or sidewalls. The tread must have a minimum depth of 2/32 of an inch. The tires must be properly inflated according to factory specifications. I'm also making sure there is proper spacing between the dual tires and the space is free from foreign objects."

Next
What happens if you forget to perform an air brake check on an air brake vehicle during the pre-trip inspection exam?
  • You will be docked 25 points
  • Performing an air brake inspection is voluntary
  • You will be reminded of the oversight
  • You will receive an automatic failure
This is a question from page 82 - click here to look up the answer

Quote From Page 117 Of The Illinois CDL Manual:

Air brake check (air brake-equipped vehicles only): Failure to perform an air brake check will result in an automatic failure of the Vehicle Inspection Test.

TruckingTruth's Advice:

If you forget to perform an air brake check, you will be automatically disqualified and will need to retest. Further, the air brake check must be performed in a very specific order. If any step is done improperly or if you forget any step, that will also be grounds for disqualification. The proper steps to checking an air brake system is as follows:

  • 1. With air pressure built up to 120 - 125 psi (fully charged system), depress the clutch and put the transmission into a low gear (keeping the transmission in gear will prevent the truck from rolling).
  • 2. Shut the engine off, but turn the key back to the "on" position (this will allow you to hear the low air pressure warning alarm later in the test).
  • 3. Release your foot off the clutch.
  • 4. Release both the yellow tractor parking brake and the red trailer parking brake if equipped (remember, the truck is in gear so you won't roll - stay off the service brakes).
  • 5. After air stabilizes (no sound of rushing air), fully apply the foot brake and hold it for one full minute (you can ask the examiner to time it for you). The system should not lose any more than 3 psi for a single vehicle and 4 psi for a combination vehicle in that minute. During this time, listen for any air leaks.
  • 6. Begin "fanning" off the air pressure by rapidly pushing and releasing the foot brake. The low air warning light and buzzer should activate before pressure drops below 60psi.
  • 7. Continue to fan the service brakes. At approximately 40 psi, the red tractor protection valve (trailer brakes) should pop out. Continue to fan off air pressure until the yellow tractor valve pops out (tractor brakes).
  • 8. Put the transmission into neutral, depress the clutch, and restart the truck.
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Next
When inspecting suspension components, you must:
  • Check the components for every axle
  • Check the components on the tractor only
  • Checking suspension components is not required
  • Check the components on the trailer only
This is a question from page 83 - click here to look up the answer

Quote From Page 118 Of The Illinois CDL Manual:

Springs/air/torque:

  • Look for missing, shifted, cracked or broken leaf springs.
  • Look for broken or distorted coil springs.
  • If vehicle is equipped with torsion bars, torque arms or other types of suspension components, check that they are not damaged and are mounted securely.
  • Air ride suspension should be checked for damage and leaks.

Mounts:

Look for cracked or broken spring hangers, missing or damaged bushings and broken, loose or missing bolts, Ubolts or other axle mounting parts. (The mounts should be checked at each point where they are secured to the vehicle frame and axle(s)).

Shock absorbers:

Check that shock absorbers are secure and that there are no leaks.

Note: Be prepared to perform the same suspension components inspection on every axle (power unit and trailer, if equipped).

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Next
When pulled by hand, how much should a brake rod move when the brakes are released?
  • No more than 2 inches
  • No more than 1.5 inches
  • No more than 1/2 inch
  • No more than 1 inch
This is a question from page 83 - click here to look up the answer

Quote From Page 118 Of The Illinois CDL Manual:

Slack adjusters:



       
  • Look for broken, loose or missing parts.

  •    
  • The angle between the push rod and adjustor arm should be a little over 90 degrees when the brakes are released and not less than 90 degrees when the brakes are applied.

  •    
  • When pulled by hand, the brake rod should not move more than 1 inch (with the brakes released).

  •    
  • The manual adjustment of automatic slack adjusters is dangerous because it gives the vehicle operator a false sense of security about the effectiveness of the braking system.

TruckingTruth's Advice:

While inspecting the slack adjuster and push rod, you should tell the examiner:

"I am now checking the slack adjuster and push rod to be sure they are properly mounted and secure, not cracked, bent, or broken. When the brakes are released and pulled by hand, the rod should not move more than approximately 1 inch."

Prev
Next
What part requires that you check the connecting links, arms and rods from the steering box to the wheel are not worn or cracked?
  • Steering linkage
  • Drive shaft
  • Slack adjusters
  • Kingpin
This is a question from page 83 - click here to look up the answer

Quote From Page 118 Of The Illinois CDL Manual:

Steering linkage:

  • See that connecting links, arms and rods from the steering box to the wheel are not worn or cracked.
  • Check that joints and sockets are not worn or loose and that there are no missing nuts, bolts or cotter keys.

TruckingTruth's Advice:

After pointing out the steering linkage, tell the examiner:

"I'm checking the steering linkage from the steering box to the wheel and making sure it is not worn, cracked, bent, or broken. I'm also making sure all joints and sockets are not worn or loose with no missing nuts, bolts, or cotter pins."

Prev
Next
How much air loss is allowed in 1 minute on a combination vehicle with no brakes applied?
  • No more than 3 psi
  • No more than 5 psi
  • No more than 4 psi
  • No more than 2 psi
This is a question from page 82 - click here to look up the answer

Quote From Page 117 Of The Illinois CDL Manual:

With the engine running, build the air pressure to governed cut-out (100-125 psi). Shut off the engine, turn the electrical power on, chock your wheels, if necessary, release the tractor protection valve and parking brake (push in), fully apply the foot brake and hold it for one minute. Check the air gauge to see if the air pressure drops more than 3 pounds in 1 minute (single vehicle) or 4 pounds in 1 minute (combination vehicle) with brake applied. When brake is unapplied, air pressure drops more than 2 pounds in 1 minute with a single vehicle and 3 pounds in 1 minute in a combination vehicle.

TruckingTruth's Advice:

Be sure to memorize how much air loss is acceptable when the service brakes are applied and not applied.

Prev
Next
Dash indicators must work when all of the following lights are turned on, except:
  • 4-way emergency flashers
  • Right Turn Signal
  • Fog lamps
  • High beam headlights
This is a question from page 81 - click here to look up the answer

Quote From Page 117 Of The Illinois CDL Manual:

Lighting indicators: Test that dash indicators work when corresponding lights are turned on:

  • Right turn signal
  • 4-way emergency flashers
  • High-beam headlights

TruckingTruth's Advice:

Be sure to demonstrate each lighting indicator on the dash and tell the examiner what you're doing. For example, while demonstrating, you should say:

"I am now checking the lighting indicators to be certain the dashboard lights function properly. The turn signal indicators work (while checking the turn signals), the 4-way emergency flashers indicator works (while checking the 4-way emergency flashers), and the high beam headlight indicator works properly."

Prev
Next
How much of a gap should be between the fifth wheel skid plate and the trailer?
  • There should be no gap at all
  • There should be a 3 to 6 inch gap on level ground
  • There should be a gap of about 1 foot on level ground
  • There should be a small gap of less than 1 inch on level ground
This is a question from page 84 - click here to look up the answer

Quote From Page 120 Of The Illinois CDL Manual:

Kingpin/apron/gap:

  • Check that the kingpin is not bent.
  • Make sure the visible part of the apron is not bent, cracked or broken.
  • Check that the trailer is laying flat on the fifth wheel skid plate (no gap).

TruckingTruth's Advice:

Be sure to tell the examiner that no gap should be present between the fifth wheel skid plate and the trailer apron.

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