How to Prep Vehicles for Winter Weather

How to prep vehicles for winter weather.

According to Randall Ray, manager, engine sales and marketing, Navistar, one of the simplest ways to keep diesel trucks running during winter is to follow the recommended warm-up times provided in the engine manual. “This allows lubricating oil to establish a film between moving parts,” he explains.

After the five-minute warming period, begin operating at reduced engine speeds and load until the vehicle reaches operating temperature.

His other suggestions:

Check the truck’s batteries and make sure they are fully charged. Freezing conditions drain a battery faster. Replace the battery if it’s close to the end of its lifecycle. Make certain batteries are securely mounted and connections are tight and clean.

Proper oil grade is essential. The Society of Automotive Engineers (SAE) defines oil viscosity (thickness) by grade. Colder temperatures require lower grade oils for correct flow during starting. Higher temperatures, in turn, call for higher grades for proper lubrication.

Check the fuel. As the seasons change, it is a good idea to check the fuel grade, as well as the cetane rating on the pump. The higher the cetane number, the easier the vehicle will start in cold weather.

When pulling back into the lot at the end of the day, or stopping for the night, fill the fuel tank, drain the water from the fuel filter housing, check the oil level and clean external surfaces of the engine and accessories to prevent dirt or snow build-up.

“Water and contaminants that occur in the fuel have a direct impact on the service life and performance of diesel engines, he notes. “They can reduce engine performance and ruin components, such as fuel pumps and injectors.

“During the winter, condensation forms on the inside of a warm fuel tank as it cools. Filling the fuel tank at the end of the day reduces how much condensation will collect. This might seem to be a minor point, but it can help reduce the chances of costly downtime and expensive repairs.”


UD Trucks North America’s Larry Schultz, vice president of aftermarket, offers these recommended maintenance steps to help keep a fleet operating trouble-free during the harsh winter months:

  • Check and adjust antifreeze protection to at least -22 degrees F.
  • Replace the engine oil, oil filter, transmission fluid and differential lube oil.
  • Inspect the engine drive belts, engine and heater hoses and radiator mountings.
  • Check the charging system, inspect and load test batteries and clean and tighten battery cables. A partially charged battery is subject to damage by freezing temperatures.
  • Replace the fuel filters, inspect all flexible fuel hoses and drain any sediment or moisture from the fuel tanks.
  • Check the preheater or glow plug operation.
  • Check the operation of the coolant heater if equipped.
  • Check the air dryer and replace the air dryer desiccant/filter every 12 months, regardless of mileage. Drain all moisture from the air tanks.
  • Replace windshield wiper blades. Check the operation of the windshield washer system, defrosters and heater.
  • Inspect the air cleaner restriction gauge and replace the air filter if required.


For trucks and trailers, winter accelerates all the bad things that can happen on the road to electrical systems, says Mark Blackford, national fleet manager at Grote Industries.

Water is bad, but salt water and ice build-up is worse, he notes. “The basic problem is that salt water corrodes wiring at a more rapid rate than plain summer water and also wicks farther along wiring than rain water.”

Before the ice and salt brine season starts, Blackford recommends taking these measures:

1. Check all electrical connections as loose connections are prime water entry points. Make sure all interior surfaces are liberally coated with anti-corrosion grease and check that the connection closes correctly and forms a tight closure.

2. Frayed wiring is a perfect entry point for salt water. It will enter any opening in the insulation and wick salt water through the harness. Therefore, inspect all wiring and make sure all frayed wiring is spliced out and properly sealed.

3. Any wires that hang down from their correct runs are prime candidates for ice build-up. As ice accumulates, the increased weight pulls on the wiring, causing more fraying, loose or severed connections, lamp dislocations and stress on splices. If a wire or cable pulls out completely, you can lose your lighting.

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