CDL · General Knowledge · 6 min read
Handling Cold and Hot Weather
- Identify critical inspection items, tire requirements, and equipment checks needed for extreme cold and hot conditions.
- Apply safe driving techniques for winter hazards, including ice, melting snow, standing water, and retarder use.
- Describe proper hot weather monitoring procedures and the safe steps for inspecting tires and pressurized cooling systems.
Winter Weather Vehicle Inspections
Before driving in winter weather, you must perform your regular vehicle inspection with extra attention given to cold-weather components. Check the cooling system to make sure it is full and has enough antifreeze to guard against freezing. You can check the level of antifreeze protection using a special coolant tester. Make sure the defrosters and cab heater work and that you know how to operate the heater; check other heaters, such as mirror or fuel tank heaters, if you use them and expect to need them.
Clear visibility and solid traction are essential during winter operations. Windshield wiper blades must be in good condition and have enough tension to press against the glass hard enough to sweep away snow. If wiper failure prevents you from seeing well enough while driving, you must stop safely and fix the problem immediately. Make sure the washer works, there is fluid in the reservoir, and you use windshield washer antifreeze to prevent the fluid from freezing. Check your tires using a tread depth gauge to confirm you have at least 4/32 inch of tread depth in every major groove on front tires, and at least 2/32 inch on all other tires.
Your winter safety inspection also covers tire chains, exterior surfaces, and the exhaust system. Carry the right number of chains and extra cross-links that fit your drive tires, checking them in advance for broken hooks, worn or broken cross-links, or bent and broken side chains. Always learn how to mount them before you find yourself stranded in ice and snow. Clean all ice and snow off your windshield, windows, mirrors, lights, and reflectors, and clear it off hand holds, steps, and deck plates to prevent dangerous slips. Remove ice from radiator shutters and ensure your winterfront is not closed too tightly, as frozen shutters or an overly restricted winterfront can cause the engine to overheat and stop. Finally, inspect the exhaust system for loose parts, unusual sounds, and signs of leaks, because leaking exhaust permits poisonous carbon monoxide to seep into a closed cab, causing drowsiness or even death.
| Inspection Item | Minimum Requirement / Safety Action |
|---|---|
| Front Tires | At least 4/32 inch tread depth in every major groove |
| Other Tires | At least 2/32 inch tread depth in major grooves |
| Tire Chains | Right size for drive tires; inspect for broken hooks, cross-links, or side chains |
| Windshield Washers | Working washer; fluid in the reservoir protected with windshield washer antifreeze |
| Winterfront & Shutters | Free of ice and not closed too tightly to avoid overheating |
Common mistakes
- Letting air out of hot tires because the pressure reads higher than the cold inflation rating, which leads to dangerous under-inflation once the tires cool.
- Using an engine brake or speed retarder on a slippery surface can cause the driving wheels to skid.
- Removing a radiator cap from a hot, pressurized cooling system, resulting in severe steam burns from erupting coolant.
- Assuming that frozen ice is more hazardous than thawing ice, overlooking the fact that ice becomes substantially more slippery as temperatures rise toward melting point.
Key points
- Inspect winter-specific gear before driving, ensuring front tires have at least 4/32 inch of tread and all other tires have at least 2/32 inch.
- Clear all ice and snow from lighting, mirrors, glass, steps, and radiator shutters, and inspect the exhaust system thoroughly to prevent carbon monoxide poisoning.
- Drive smoothly on winter roads, shut off speed retarders on slippery surfaces, and watch for disappearing spray from other vehicles as a warning of ice.
- If you cannot avoid deep standing water, slow down, select a low gear, and use light brake pressure while crossing; continue light pressure for a short distance afterward to heat and dry the brakes, then make a test stop when safe.
- In hot weather, inspect tires every two hours or 100 miles, never bleed air from hot tires, and wait for tires too hot to touch to cool naturally.
- Never open a pressurized cooling system while it is hot; check see-through recovery tanks instead, or wait until the radiator cap is cool enough to touch with a bare hand before venting pressure.
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