Heavy-duty diesel engines can power through virtually any weather, but winter poses a serious threat to their performance. In order to keep your fleet reliable in sub-freezing temperatures, it’s important to winterize your trucks and/or buses. This means taking steps to prevent fuel system, starting/charging system, air brake system and cooling system failures, rather than simply reacting to an issue once it arises. Here are the four main functions to address when winterizing:
1. Fuel
The paraffin in diesel fuel can create a buildup of crystals or wax in cold weather, clogging the fuel filter and potentially leading to lack of fueling. Many fleet managers use a “winter blend” of premium fuel formulated for cold weather. Winterized fuels usually include a de-icer, wax anti-gelling agent and cold-flow improver. You can buy all of these additives separately, but if you go this route, be sure to check your owner’s manual for levels and guidelines.
2. Air-Brakes / Air Dryer
When water gets into your air-brake system in the dead of winter due to condensation from when the hotter compressed air enters the cold plumbing, it will almost certainly turn to ice. This can cause frozen valves, air dryers and other air system components. The ice blocks air from reaching the brake chambers, which may cause wheels to lock or fail to stop when the brake is applied.
Winterizing your air-brake systems involves maintenance of your air dryer, constant draining of any condensation in the air system through the air tanks, and possibly the addition of air brake alcohol before and throughout winter to ensure the systems are free of ice. It is recommended these tasks be done by a professional who understands how these systems work.
3. Battery
Even in diesel engines, batteries drain relatively quickly in cold conditions. Ideally, you want to check your batteries right before the first forecast cold snap. If any batteries are toward the end of a standard 36- to 60-month cycle, replace them. For the ones that are well-charged, the best practices are a Load Test and double checking them for secure mounting and clean connections.
4. Cooling System
It might seem counterintuitive to tend to cooling systems ahead of cold weather, but diesel engines are taxing on these systems year-round. Poor cooling maintenance can lead to premature corrosion and frozen cooling systems, causing leaks and an array of other problems. You should also be mindful of additive levels and freeze points and check them on a regular basis to adjust your coolant accordingly.
Beyond the Owner’s Manual
Your owner’s manual will go a long way toward helping you prepare your fleet for winter, but there is no substitute for professional fleet winterization. The steps above represent the bare minimum for winterizing heavy-duty diesel engines; there are additional parts to consider, which is why many New Jersey school bus, municipal and private fleet owners call On-Site Fleet Service for complete winterization services. Learn more about our company, and call us at 732-651-1600 to speak with one of our certified mechanics.
