This blog post was initially published on Sept. 4, 2019.
Winter is coming again. So how do we prepare? This depends greatly on your geographical location. Those of you who operate in dry areas may put less emphasis on preparation for this season. For those of you who operate in a wet or cold climate, some checklist items that come to mind may be tires and wiper blades.
Regardless of your location, it is important to perform periodic seasonal maintenance. When doing so, I prefer to consider the operation of specific systems rather than individual components.
1. For example, although testing coolant is important by itself, I prefer looking at the cooling system as a whole. That includes the hose condition, clamp torque, pressure testing the system and radiator cap, checking thermostat operation, radiator condition, and cooling fan operation. The fan drive system needs to be checked thoroughly, too.
Whenever I perform cooling system repairs, I put the system through its paces afterward to ensure the cooling fan activates at its designated temperature and shuts off again at the designated temperature. Utilizing a laptop computer or diagnostic tool to monitor coolant temperatures during operation as well as fan on/off operation may be a part of that test.
2. The same applies to compressed air system maintenance in which air dryer service takes place. Check for air leaks in the system as well as accumulation of oil in the air reservoirs, both of which may be indicative of air compressor failure. Moisture or oil in the system will cause frozen or improperly operating air valves and frozen air lines. Having a bus unable to move because it cannot build air pressure is frustrating, to say the least.
Air dryer maintenance should be performed annually in wet climates. Follow the manufacturer recommendation at a minimum. Due to your geographic location, you may need a stricter maintenance program.
3. Other systems to review in your winter preparation include the heating and defrosting system. Ensuring all heaters operate at both high and low speeds, as well as cleaning or replacing heater filters, and cleaning the lint and dirt off of heater cores, will increase the efficiency of this system and create a more comfortable and reliable ride.
4. With fewer hours of daylight during the winter months, emphasis should be placed on lighting systems, including the instrument cluster, switch panel lights, and dome lights. Use of the proper candle power bulbs when replacing bulbs will greatly improve the interior light.
5. If you are operating in cold climates and use an auxiliary heating system, such as Webasto or Espar, now is the time to make sure it is operating at peak capacity and OEM maintenance guidelines are followed. Remember to open all the heater system shut-off valves.
6. Fuel system maintenance is especially important during cold weather. If you have not started adding fuel system treatment, now is the time. Fuel filters and water separators should be serviced and fuel bowls cleaned of sediment. Keeping fuel tanks above the half-full level will reduce condensation accumulating in the tank. Talk to your fuel supplier about pre-treating fuel for the winter months. Test fuel system heaters as needed.
7. How about starting and charging systems? If you use battery maintainers, are they all working? Are block heaters and receptacles working and in good condition? Do you have a good supply of extension cords to power these units?
8. Last but not least, ensure all emergency equipment is in good working condition and fully stocked. Keeping on top of seasonal maintenance can only help our buses stay safe and reliable.
Brad Barker has more than 40 years of experience in school bus maintenance as a shop manager and technician. He has written numerous articles for SBF. He can be reached at firstname.lastname@example.org.