Truck Topics

Pre-Winter Truck Review

Fall is here, and it's time to prepare your truck for winter driving, especially if your destinations include the frigid temperatures, snow and ice of the north country.

There's really no escape from the cold weather. We've all experienced, or at least have seen the news reports over the past several years, of the freak ice and snowstorms that have hit even the deep southern areas of the US.

The next expedited load can take you anywhere in this country and many parts of Canada, and your truck (and you) have to be prepared for the weather you'll meet on your journey.

It's a rule that if something might break, it will do so in bitter cold weather. Regardless of the cause of a winter breakdown, it can escalate from an inconvenience into a life-threatening situation.

Although modern trucks are built for a wide range of places, temperatures and climates, and are more reliable than ever, winter weather will find and exploit any weakness that exists in the truck's various systems.

Prime areas of concern would include:

- Batteries and Charging System
- Engine Cooling System
- Air Dryer Systems
- Cab and Sleeper


Batteries and Charging System
Next to the problems of fuel, winter is probably hardest on the electrical system of your truck. One of the unfortunate ironies of winter is that the cold temperatures are extremely tough on an electrical system that already has a heavy load, operating the lights, the heater and other accessories.

As the outside temperature drops, batteries generate fewer cranking amps. If your batteries are more than a year or two old, it's best to have them tested for their ability to hold a charge.

If a battery's power is rated at a temperature of 80 F, a temperature of zero degrees will drop its rated power down to only 40 percent of that figure. For those expediters operating in a Class 8 truck, it can take around 1,800 amps to start that big motor - that's why the cold cranking amps rating is important.

The multi-battery arrangement of the Class 7 and 8 trucks is essential to not only provide the heavy amperage draw of starting, but also to furnish the reserve power needed to power accessory items when the motor is shut down. For example, a set of four 675 CCA batteries will provide up to 2,700 amps of starting power at zero. At 32 F, almost 4,400 amps are available. That's reserve power.

While doing battery checks, it's also a great time to pull the terminals and give them a cleaning and coat them (and all exposed wiring) with a dielectric compound.

You should have a qualified technician check alternator output to ensure that it's up to spec's. Examine fan belts for cracks, fraying, polishing and check other accessory drive mechanisms, including brackets. Pulleys are harder to spin during engine start-ups in cold temperatures and that puts extra strain on belts. It's a good time to inspect the pulleys as well for proper alignment.

Wiring should also be checked to see that it's correctly routed and attached and supported against the frame.

Engine Heaters
Though not truly part of the electrical/starting system, engine heaters can ease the strain on the batteries and other components in cold-start situations, and at the same time, reduce metal wear due to cold, thick oil.

One method to keep the engine warm is by the use of a coolant heater, which can be a remote-mounted tank (shore powered or diesel-powered) or an immersion-block design. With both types, the engine's coolant is heated to around 160 degrees and circulated through the engine block.

For example, a 17,000-Btu/hr-coolant heater will raise a Class 8's engine temperature 100 degrees above the outside temperature in about an hour.


Cooling System
We'll assume that all of the belts have been checked during the electrical system examination, so turn your attention to the hoses and clamps. The coolant hose is a vital, yet sometimes overlooked component in the cooling system. In addition to absorbing the vibration that is transmitted from the engine to the radiator, the hoses carry coolant to and from the radiator. Without flexible rubber hoses, the vibration may break off at the inlet or outlet connections of the radiator.

Hoses are expected to carry more than 7,000 gallons of hot coolant per hour, while they are exposed to under-hood temperatures in excess of 275 degrees F. and under pressure of 15 to 18 psi.

Inspect all hose connections for leaks, cracks and soft spots. If a hose exhibits any of those symptoms, replace it. Maintenance experts recommend the use of long-life silicone hoses, which have become an industry standard.

It might be good time to replace any suspect hose clamps at this point. Recommended are the stainless steel types with screw securement. A rule of thumb would be to not over-tighten clamps but tighten them until the hose just starts to bulge. Run the engine to operating temperature and re-tighten the clamps.

Thermostat housings can become badly corroded with age and may not seal properly when the new hose is installed. If the housing is rough or pitted, replace it.

The coolant should be a 50-50 mix of soft, clean water and low-silicate (non-automotive) anti-freeze. Your technician can use special gauges to measure the coolant's level of protection.
A 50-50 mix of ethylene glycol antifreeze and water will protect against freezing down to minus 34 degrees Fahrenheit. If you need greater low-temp protection, a higher percentage of antifreeze is called for, but the experts say to avoid concentrations greater than 60/40.

Truck engines are designed with an operating temperature range of around 195 to 200 degrees Fahrenheit regardless of ambient temperature and that's the job of the fan drive and thermostat.

Your mechanic should ensure that the thermostat operates properly. Thermostats often fail in the open position, so the engine will require a longer to warm up time and may run cooler if not under load.

Coolant filters should be checked and cleansed of various contaminants. Many filters also gradually release Supplemental Coolant Additives (SCA's), which are corrosion-fighting chemicals. If your mechanic discovers that the SCAs are gone, the filter should be changed.

The extra-cold air that blasts through the radiator at highway speeds can overcool an engine resulting in damage from carbon and varnish buildup on the valve stems and oil contamination from unburned combustion products.

Winterfronts are useful in maintaining a satisfactory engine temperature in extreme conditions. Because over-restricted flow can raise temperatures in the charge-air cooler, some truck manufacturers allow only certain winterfronts. The restricted flow can lead to high exhaust temperatures, power loss, excessive fan cycling and potential engine damage.

It's also important that the winterfront opening directs the airflow from side to side so the engine is cooled evenly. Offset or unbalanced openings also cause fan flexing as blades run in and out of the airflow, risking fatigue damage.

Air Dryer Systems
Moisture in your truck's air system can be a big problem in the frigid temperatures of winter, as anyone who has suffered dragging or non-functional brakes can testify.

Water in the system will freeze and any oil will thicken. The standard practice of opening the drain valve once a day is probably not enough. Water and other contaminants can still enter the system and that's where the air dryer comes into play, in fact, they've been standard equipment for a number of years.
The air dryer's function is to remove contaminants and moisture before the air reaches the supply tank.

The two main components in the air dryer, a filter and a heating element, must be occasionally replaced. The filters usually have a service life of two to three years, but if you or your mechanic discovers water when draining the wet tank, it's time for replacement.

Have your technician perform an electrical check on the air dryer's heating element as well as draining the air tanks to remove accumulated residue. Also, ask your tech about the viability of adding air system alcohol to the tanks.

Cab and Sleeper Heat
We've been advised for many years to give our homes an energy makeover, i.e., install energy-efficient windows, add insulation, etc. Well, the same can apply to the cab and sleeper.
Ensure structural integrity: Repair loose sheet metal, replace insulation where necessary and weather strip the doors.
Have your technician check the heater/defroster and its blower motor/fan as well as any heater hoses that run back to the sleeper.

Other areas of concern

Wipers and washers
If the wiper blades are more than six months old, change them. You might consider using rubber covered winter wiper blades or heated blades. Ensure that the arms move through their full stroke at all speeds.

See that the reservoir is full of fluid, and that the washer pumps strongly. The experts strongly recommend the use an ice-melting washer fluid rather than just the traditional blue fluid. Use the washer fluids containing glycol - it will melt thin ice from the windshield.

Exhaust system
Have your mechanic inspect the system for leaks, especially the piping under the cab and sleeper. Leaks often develop near the air intake for the cab's fresh-air system; if these fumes leak in during bunk time, it's a potentially lethal situation.

Most straight trucks have frame mounted exhaust systems; unfortunately, fumes and carbon monoxide settle in low spots. Because of this, it's best to park the truck nose-into-the-wind. If you park with the truck's rear to the wind, the fumes get blown forward and can enter the air intake system and then the fresh air system.

Tires
Inspect and replace any worn tires now. Obviously, you will have better traction with the new, deeper tread, and the cold temperatures will slow the wear rate, yielding more tread life.  Consider installing lug-type treads on drive wheels for better traction on snow and ice. Ensure that all the tires are inflated to proper pressures. Examine the wheels closely for bends and cracks, and check the lug nuts for signs of looseness or breakage.