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Getting your vehicle ready for winter

General Knowledge3 minManual section 2.13.1

Before winter driving, do your regular inspection but give extra attention to the items cold, snow and ice affect most: coolant, heaters and defrosters, wipers, tires and chains, lights, windows, steps, radiator shutters, and the exhaust system.

Fluids, heat and visibility

  • Coolant level and antifreeze: the cooling system must be full, with enough antifreeze to protect it from freezing. Check with a special coolant tester.
  • Defrosting and heating equipment: make sure the defrosters work; you need them to drive safely. Make sure the heater works and you know how to use it. If you use and expect to need other heaters (mirror heaters, battery box heaters, fuel tank heaters), check them too.
  • Wipers and washers: wiper blades must be in good condition and press hard enough on the glass to wipe it clean, or they will not clear snow. The washer must work and the reservoir must have fluid. Use windshield washer antifreeze so the fluid does not freeze. If you cannot see well while driving (for example, the wipers fail), stop safely and fix it.
  • Lights and reflectors: must be clean; they matter even more in bad weather. During bad weather, stop now and then to check that they are still clean and working.
  • Windows and mirrors: remove all ice and snow before starting. Use a windshield scraper, snow brush and the defroster as needed.

Tires and tire chains

  • Tread depth: the drive tires must give traction to push the rig over wet roads and through snow; the steering tires need traction to steer. Enough tread is especially important in winter. Front tires need at least 4/32 inch of tread in each major groove; all other tires need at least 2/32 inch. Deeper tread is better. Use a gauge to check.
  • Tire chains: you may face conditions where you cannot drive without chains, even to reach a safe place. Carry the right number of chains plus extra cross-links, and make sure they fit your drive tires. Look for hooks that are broken, cross-links that are worn or broken, and side chains that are bent or broken. Practice putting chains on ahead of time, not for the first time in snow and ice.

Steps, radiator and exhaust

  • Hand holds, steps and deck plates: clear off ice and snow so you are less likely to slip and fall.
  • Radiator shutters and winterfront: clear any ice off the shutters, and do not close the winterfront too far. Shutters frozen closed or a winterfront that blocks too much air can make the engine overheat and quit, even in cold weather.
  • Exhaust system: leaks are especially dangerous when cab ventilation is poor (windows rolled up in cold weather). Loose connections can let poisonous carbon monoxide into the cab. Carbon monoxide makes you sleepy, and in large enough amounts it can kill you. Check the exhaust for loose parts and for sounds and signs of leaks.
Check your state

Some states and mountain passes have their own chain-control laws (when chains must be carried or used). Check your state manual and road signs.

References and scope

The topic reference is listed below. Sources support verification; the lesson itself is here. The current content needs technical and language review before public launch.

Manual reference: 2.13.1

Official CDL handbook · Utah ↗StatesOur editorial approach

Put it into practice

Educational questions with explanations. The answer review also works without the interactive quiz.

Preparing your questions…

Review questions with answers

  1. How can you check that the cooling system has enough antifreeze to protect against freezing?
    1. By the color of the exhaust
    2. With a special coolant tester
    3. By feeling the radiator cap
    4. By checking oil pressure
    Show answer
    With a special coolant tester

    Antifreeze protection can be checked with a special coolant tester.

  2. What is the minimum tread depth required in every major groove on front tires?
    1. 2/32 inch
    2. 1/32 inch
    3. 6/32 inch
    4. 4/32 inch
    Show answer
    4/32 inch

    Front tires need at least 4/32 inch in every major groove; other tires need at least 2/32 inch.

  3. What is the minimum tread depth for tires other than the front tires?
    1. 2/32 inch
    2. 4/32 inch
    3. 3/32 inch
    4. 1/32 inch
    Show answer
    2/32 inch

    Tires other than the front tires must have at least 2/32 inch of tread.

  4. When checking tire chains before winter, you should:
    1. Only count the chains
    2. Check them only after the first snow
    3. Carry the right number plus extra cross-links and check for broken hooks and worn links
    4. Make sure they fit the steering tires only
    Show answer
    Carry the right number plus extra cross-links and check for broken hooks and worn links

    Carry enough chains plus spare cross-links, be sure they fit your drive tires, and look for broken hooks and worn or broken links.

  5. When is the best time to learn how to put on tire chains?
    1. The first time you are stuck in snow
    2. Before you need to do it in snow and ice
    3. Only if your carrier requires it
    4. After an inspection officer tells you to
    Show answer
    Before you need to do it in snow and ice

    Practice installing chains ahead of time, not for the first time in snow and ice.

  6. If the radiator shutters freeze shut or the winterfront is closed too tightly:
    1. The engine will warm up faster and run better
    2. The heater will stop working
    3. Nothing happens in cold weather
    4. The engine may overheat and stop
    Show answer
    The engine may overheat and stop

    Remove ice from radiator shutters and do not close the winterfront too tightly, or the engine may overheat and stop.

  7. Why are exhaust leaks especially dangerous in winter?
    1. Windows are closed, so poisonous carbon monoxide can build up in the cab
    2. Cold air makes exhaust explode
    3. Exhaust freezes the brakes
    4. Leaks lower tire pressure
    Show answer
    Windows are closed, so poisonous carbon monoxide can build up in the cab

    With poor cab ventilation, loose exhaust connections can let carbon monoxide leak in. It causes sleepiness and can kill.

  8. Carbon monoxide from an exhaust leak will first make you:
    1. Hungry
    2. Cold
    3. Sleepy
    4. More alert
    Show answer
    Sleepy

    Carbon monoxide gas causes sleepiness, and in large enough amounts it can kill you.

  9. Why should you remove ice and snow from hand holds, steps and deck plates?
    1. To reduce vehicle weight
    2. To reduce the danger of slipping
    3. To improve fuel economy
    4. To pass the brake test
    Show answer
    To reduce the danger of slipping

    Removing ice and snow from hand holds, steps and deck plates reduces the danger of slipping.

  10. Your wipers fail in a snowstorm and you cannot see well. You should:
    1. Keep driving and lean out the window
    2. Follow the taillights ahead closely
    3. Turn on the defroster and keep going
    4. Stop safely and fix the problem
    Show answer
    Stop safely and fix the problem

    When you can no longer see well, such as when the wipers quit, pull over safely and fix the problem before going on.

  11. To keep the windshield washer fluid from freezing, use:
    1. Windshield washer antifreeze
    2. Plain water
    3. Engine coolant
    4. Hot water
    Show answer
    Windshield washer antifreeze

    Use windshield washer antifreeze to prevent freezing of the washer liquid.