I don't think that it is premature to talk about "Winter Preparation Techniques for Fleets"; in fact as I write this, Denver, Co. is having its first snowstorm.
There are many check-points that more "maintenance-sophisticated" fleets have built into their winter preparedness programs; but on the other hand, there are an abundance of smaller and independent fleets that have to revisit theirs from a new perspective each and every year.
Below are a number of simple things that I recommend carriers who operates in inclement weather should address to minimize cold weather breakdowns and maximize delivery window commitments. Obviously the bar gets raised for fleets that operate predominately in the northern, northwestern, and north central sections of the U.S.
I recognize that many may view these items as Maintenance 101, but as stated earlier, many may not:
* Cooling systems must be charged and validated for freeze protection as well as the SCA (Supplemental Coolant Additive) levels. Antifreeze types today, which, by the way has become a technical issue in and of itself, and SCA consistency is paramount as both will have tendencies, under sustained heat and time, to chemically breakdown and minimize protection. Simply adding antifreeze isn't adequate and refractometers must be used to determine the acceptable dosage of the proper antifreeze in addition to OEM/aftermarket supplied test procedures and devices to check SCA levels.
* Fuel purchases and availability should be reviewed and high attention given to the consistency, gel points, and respective flow restriction attributes. Fuel tanks, especially aluminum tanks, will actually make water with ambient temperature changes, thus permitting the growth of algae in the tanks and sometimes catastrophic fuel system failure. There are many products on the market that for the most part provide good results. Many fleets run mixtures of #1 and #2 diesel and these decisions are dependent upon operational demographics.
* Fuel/water separators should be serviced and brought up to OEM specifications.
* Air dryers must be serviced and desiccant inspected for proper absorptive values in addition to the same attention and service applied to the air controlled water emitting valves. Some trucks may have had the air dryers by-passed due to line or inoperative valve conditions during the warmer months and this will definitely bite you as the temperatures drops.
* Cold water leaks occur easily and often as the ambient temperature changes, as the aluminum coolant neck housings expand and contract. This is not a serious issue, but it may be just enough to cause low-coolant sensors to activate shutdown programming in your ECU. Careful tightening of hose clamps is recommended at your next P.M.
* Trailer and Dolly air systems must be serviced and purged of any condensation that's occurred over the warmer months. Many tractor air dryers are capable of removing the condensation in the trailer when connected, but trailers that have been un-tethered for a period of time in cold weather have converted the condensation in the system to ice that could definitely cause initial hook-up problems causing possible brake drag. Now you have tire issues that you didn't expect.
* The cab heater cores in many units have not been active during the summer months and these must be inspected to insure that no detrimental corrosion has occurred while they were inactive. Drain lines must also be cleared of debris.
* Tires are also more susceptible to damage in cold weather conditions. Extremely cold temperatures can cause sidewalls to become very brittle and subject to impact damage from curbing, etc.
It's also important to remember that during the heat of the summer air pressure tends to elevate; as cooler weather approaches the acceptable PSI gauged in your tires will be much different than on a cooler day. Your air pressure program is just as important during winter months as it is during summer months.
Good luck with your winter preparations.