Nothing is more annoying than a maintenance oversight causing a machine to go down –unless it’s a maintenance failure that causes a machine to go down in a howling artic wind.
As the days get shorter and the weather turns colder, contractors are scrambling to finish projects. And while the work has to get done, this is no time to cut corners on your maintenance.
Winter and cold weather is almost always harder on equipment than the warmer months. Some experts even contend that more damage is done in the first ten seconds after cold-starting a diesel engine than in any other point in its operating cycle.
If you want to maximize uptime given the limited daylight available in the months ahead, then now’s the time to go through your maintenance protocols with a fine-tooth comb. With each passing week, these tasks will only get harder to complete. We asked a handful of equipment experts what they recommended. Here’s what they said.
• Diesel fuel. As the mercury drops, diesel can gel and develop water condensation. Filters can clog, and sediment can collect in the bottom of storage containers and the fuel tanks of unused equipment. Check your onboard fuel filters to make sure they’re clean and functioning properly. But don’t substitute a less efficient filter to fix a perceived problem with premature plugging. A less efficient filter may extend the period before plugging occurs, but it will also allow contaminants to flow downstream.
Heating diesel fuel above the cloud point is the simplest and most reliable way to avoid plugged fuel filters in the winter. An OEM-approved all-in-one fuel filter, water separator, and heater will warm the fuel close to the filter element and work continuously to re-liquefy wax and ice crystals with no other add-on hardware.
Talk to your fuel supplier about what they do to reduce condensation and other contaminants during transport and delivery, and what you can do at your fuel islands, storage tanks and jobsites to keep fuel clean. Also check with your fuel suppliers to ensure that they are providing winter blend diesel fuel rather than the No. 2 diesel commonly supplied in the spring and summer.
• Lube oils. As the amount of daylight shrinks, you may find it convenient to do your lube oil changes before temperatures plunge below freezing. Diesel oils “shear down” over time, which means their viscosity range shrinks. And as oil accumulates soot, it becomes thicker and harder to pump, decreasing horsepower. As a result, oil that is nearing the end of its useful life will not provide optimal engine protection, especially in those critical cold-start situations.
A key consideration is the right viscosity. You may want to switch from a 15W-40 to a 5W-40 as long as you’re within the guidelines provided by your OEM. Pour point depressants are sometimes added to engine oils in cold weather, but many of today’s diesel lube oils will include this in their formulas. Check with your lube oil supplier and OEM before using any aftermarket additive.
• Air filter maintenance and replacement is a routine task, but now is the ideal time to do so. Earthmoving in the summer and fall often creates a good deal of airborne dust, so your machines should be due anyway. Pop in a new filter now, and in most cases, you shouldn’t have to worry about this until well into next year. Also use this time to check for air leaks that may allow unfiltered air to be pulled into the engine. Contaminated air is a major cause of premature engine failure.
• Diesel exhaust fluid or DEF is now used in almost all Tier 4 Final engines and will freeze in temperatures below 32 degrees Fahrenheit, but it can freeze and thaw in the DEF reservoirs on your machines without losing any of its functionality. DEF storage in the shop or fueling area is another matter. Make sure you’ve stored your bulk supplies of DEF where they can’t freeze, otherwise you’ll have to thaw it out before dispensing. Leave room for expansion, as DEF can swell in volume up to seven percent in the winter months.
• Coolants. Over the summer, operators, drivers and maintenance people may have topped off the cooling systems on many of your trucks and machines. That makes it likely that the specific gravity of these fluids is questionable. Occasionally, people top off with the wrong coolant as well. Keep in mind that coolant doesn’t just keep the engine from overheating, it also protects against freezing, scale, corrosion and pitting on the liners in diesel engines. Test the coolant with a refractometer for the best accuracy.
If the engine has a coolant filter, make sure it is replaced according to the OEM schedule. Also examine the radiator and coolant lines and hoses for cracks or leaks. Check to make sure the radiator cap fits tight and holds pressure. Make sure you know which coolant to use, conventional or OAT (organic acid technology), and never mix the two.
• Heaters. If your truck or machine is equipped with electric block, oil pan or battery pack heaters, check these to confirm that they are working. On some machines, a crankcase breather tube heater is also used, so check that as well.
Even though cold weather won’t shorten the life of a battery, poor maintenance can stress the charging system. An undercharged battery will perform adequately in the warmer months, but at zero degrees Fahrenheit, the demands on a battery at start up can increase by 200 percent. Even in good condition, a battery in cold weather may only be able to provide 40 percent of the cranking power it has in the summer.
To prevent battery failure in winter, you should first make sure your batteries are fully charged in the fall. If the battery is not sealed, check the level of the electrolyte. It should be up to the full mark. If not, the plates that have been exposed to air will never perform to their full capacity again. Also check the rated current output of the alternator and load test the current output of the battery.
Make sure the battery posts and connecting cables are clean. If deposits are showing, disconnect and clean both with a little baking soda and a battery brush. Spray products applied to the posts and clamps are available at auto parts stores and can seal out moisture and improve electrical contact.
If a truck or machine will be idle for any length of time, you may want to disconnect the battery and bring it inside. Connect it to a battery maintainer to keep it at a full state of charge and ready to use.
Central lubrication and autolube systems may have a hard time moving grease in extremely cold temperatures. Manually greasing all the zerks on a machine can challenge even experienced maintenance technicians, because grease lubrication points tend to be in areas that are hard to access and the grease is often expected to travel down long narrow lines. Battery powered grease guns can help move stiff grease, but care should be taken not to over-pressurize the grease and blow out a fitting.
Some equipment can be fitted with grease heaters to keep things flowing. But where there is a lot of temperature variability, a shift to winter grades in the fall may be your best bet. Winter grades often feature a lower viscosity base fluid and a softer NLGI (National Lubricating Grease Institute) grade. All-season greases are available, but for severe cold conditions, check with your grease supplier and OEM for recommendations.
Undercarriage and cleaning
Pressure washing your undercarriage occasionally is a good idea, and it’s important to do so before freezing temperatures arise. Keeping track components clean will help extend their life and help you spot wear
more easily. Keep accumulated snow and ice off your machines with a heated pressure washing. Mud and debris can freeze your tracks in place, making it impossible to move the machine until you can find a way to unfreeze it.
The same holds true for the exterior of any machine. A thorough cleaning will remove built up mud before it freezes and help you identify oil leaks and other problems that may need attention.
Tires can survive being outside all winter, but the air pressure in any tire goes down over time, especially when it’s cold. Be sure your tires are inflated and the stems are covered with the correct cap to prevent moisture accumulation. If you have radials, don’t drive away too quickly if they’re frozen and have flat spots where the contact patch has sat on the ground. Let the tire warm up before hitting highway speeds. Also, remove counterweights when not in use to reduce stress on the tires. Clean out rocks and debris between the tread blocks, and check the sidewalls for evidence of cracking.
While today’s diesel engines don’t need a warm up period, coach your operators to give the hydraulics and other fluids a bit of time to reach their regular operating temperature before putting the machine to work. Hoses, O-rings, and some types of fittings may be frozen and rupture or crack if they’re stressed on a cold morning.
That being said, also warn operators not to leave a machine idling for longer than a minute or two. Idling in cold weather will add considerable amounts of soot to the diesel particulate filters and diesel oxidation catalysts.
To keep your operators safe and comfortably productive, change out the cabin air filters if your machines have them, and check the condition of the air and heat controls in the cab. Uncomfortable operators are less productive, and condensation inside the cab can obscure visibility.
If you’re not using your air compressor daily during the winter, it’s still a good idea to start it up and let it run until it reaches operating temperature at least once a month. This is especially true where the ambient temperature is frequently below freezing. Also check all the hoses and belts on an air compressor for cracks and wear before winter begins, and replace as needed. If you’re using it daily, check the hoses and belts before you crank it up. The airend lubrication oil spec can change according to the ambient temperature, so make sure you have the correct lubrication on hand and use it according to the specs in the operator’s manual.