With winter around the corner, Mitsubishi Fuso Truck of America has issued tips for truck fleets to help minimize downtime.

Here is a list of winter preparation measures that should be part of every truck maintenance program. Some are routine and apply to every vehicle in the fleet and some are more specific to medium-duty trucks, but all will help keep trucks safely on the road in spite of the rigors of winter driving.

One of the newest items in the maintenance checklist appears courtesy of the EPA 2010 emissions regulations — specifically for diesel engine models using urea-based diesel exhaust fluid (DEF) in their emissions control systems. The freezing point of DEF is 12°F, so it is likely to freeze in many northern locales, but should thaw under normal operation within 45 minutes, as virtually all medium-duty trucks' emissions systems are designed to accommodate this.

• Check and maintain engine heaters. Note that, while medium-duty trucks have typically used block heaters to keep engine oil warm, some newer models use oil-pan heaters. These latter units are mounted to the pan, and heat the engine pan and oil directly, so they can be smaller and more efficient than block heaters. Block heaters, on the other hand, are typically mounted 12 inches or so above the oil pan, and generally heat the engine coolant, which in turn conducts heat to the block to aid in cold-weather starting.

• Check coolant for proper protection levels. Coolant life is typically specified by the coolant manufacturers at 24 months, so if coolant is older than that, the system should be flushed and the coolant replaced. While the antifreeze properties of the coolant may not dissipate with time, additives that provide corrosion protection, anti-gumming and other ancillary protection functions do break down with time, compromising overall performance.

• For diesel engine models, make sure fuel is ASTM D-975 Grade 1 diesel in areas where temperatures may drop below 10°F. Note that for diesel particulate filter-equipped vehicles, ultra-low sulfur diesel is required in all temperature conditions.

• Service the fuel filter, and drain the water separator to prevent freezing.

• Test the battery and clean the connections. While battery degradation occurs much more rapidly in hot weather, it is under the high starting load they face in cold weather that batteries typically fail.

• Check windshields for minor chips and pitting. As temperatures decrease and sheet metal contracts, stress on windshields can increase. Have small chips repaired to help avoid crack propagation and the need for a full windshield replacement.

• Check windshield wiper blade condition and replace as necessary.

• Check and fill windshield washer reservoirs regularly, being sure to use proper winter dilution levels.

• Check heater/defroster operation, including function/position of the directional vanes in the system to assure effective defrosting.

• Check tire condition and make sure tread thickness is a minimum of 5/32 inch for winter driving. Ensure tires are properly inflated. For harsh winter conditions, consider a truck with a limited-slip differential or consider adding a 4-wheel drive model.

• Put tire chains in the vehicle if severe snow or ice conditions are anticipated.

• Check exhaust systems to assure they are free of leaks. Sitting in slow-moving traffic, creeping because of heavy weather, or parked with the engine running to maintain cab temperature can increase the risk of carbon monoxide entry into the cabin.

• On diesel-engine models, check glow plug operation.

• Check ABS operation at the start of the winter season, even if this requires a variance from the regular brake maintenance schedule. Also monitor stroke adjustment on drum brakes, fluid levels and parking brake operation.

• Clean the cab, body and undercarriage weekly to remove road salts in heavy snow areas.

• Keep radiator frontal surface clean and free of bugs, dirt and debris.

• Check the operation of heated mirrors, if so equipped.

• Check all belts and hoses, and replace as necessary.

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