Motorcoach Winterization 2.0

Presented as part of ABA’s BISC & BusMARC 2021 Virtual Safety & Maintenance Series

The American Bus Association’s Bus Industry Safety Council (BISC) and Bus Maintenance Repair Council’s (BusMARC) 2021 Virtual Safety & Maintenance Series offered a sequence of educational webinars early this year, covering a variety of industry-related topics.


This panel was moderated by BusMARC Chair Mike McDonal, Director of Regulatory Compliance and Industry Relations at Saucon Technologies. 

Panel members included industry experts Derek Brown of TEMSA, Dany Landry of ABC Companies, Robert Hitt of Prevost, Steve Kiner of Motor Coach Industries (MCI) and New Flyer Industries, and Ben Kopp of Coach USA. 

The panel covered topics including maintenance of unused vehicles, increased pre-trip inspection and stocking processes, special fuel considerations, effective storage methods, and changing and maintaining vehicle equipment. It is presented here in an abridged format:

With the way things have changed, the wheels have not turned nearly as much as they did the previous year. What type of adjustments have you made on your PM scheduling?

Ben Kopp: Our biggest adjustment has been moving to a more day-focused schedule. COVID forced us to at least look at all of our buses every so many days depending on where they are and the type of bus. That varies. We make sure we are not forgetting to recheck our fluids and things like that every so many days instead of just relying on mileage intervals. Followed by making sure our fluids are completely full all the time. Especially anti-freeze, when we might have a bus that lives in the South suddenly come to the North for something. You do not want to catch it off guard and end up with frozen pipes.

Should companies be looking at any type of interim inspections? 

Derek Brown: I would recommend exercising the coach – not just starting it, but actually moving it. Check for electrical operation of lights. Make sure everything is still in working order. I see a lot of issues with corrosion and sitting in the parking lot does just as much harm if not more than daily operation. I see a lot of DEF cylinder failures from sitting. It is a good idea to check your freeze point on your coolant so it is safe in cold climates. Make sure your windshield washer fluid is not full of water and freezing up. Fully charge the batteries or remove them.

Steve Kiner: Corrosion can do as much damage to the coach while it is sitting still as when you are running down the road. Keep an eye on that battery post, for example. The coach is sitting still, and you are losing a couple of amps an hour just from memory power. Frequently inspect those batteries. Stick a charger on them to make sure they are topped off. One of the items that we have noticed over the summer from the coaches being parked is an algae bloom in the fuel. Customers are calling in with frequent fuel filters being plugged up. 

For vehicles that have had fluids in them which are not being circulated, what kind of shelf life would they have within those vehicles?

Dany Landry: That is a big thing you want to check: shelf life. I see a lot of problems with DEF when no one is actually checking that DEF or making sure that urea concentration is correct. Especially after sitting for winterization or sitting during our COVID spell, we had a lot of DEF that went bad because urea concentration failed. 

Also, check fluids and coolants. Another big thing with checking your seals is making sure those seals are not starting to fall apart. Check your seals such as your AC compressors. AC compressors can have what is called a weeping seal. If we are not exercising our components or engine and actually starting the vehicle up and making sure things work, that seal tends to dry out. What ends up happening is the seal starts to leak once the vehicle is put back into operation.

With belts not being driven as frequently, are there any different types of inspections we should introduce? What about the engine?

Robert Hitt: That is an excellent point. We are very good at checking belts. What we are not so good at is getting our mechanics to spin those idler pulleys once the belt is removed or even removing the belts for the inspection. That is a key item on our side that we have really stressed at all our locations. Also, on your alternators, there may be a dead spot in that bearing. Any time you have the opportunity to actually remove that belt – not just twist it over and look for cracking or any problems – and spin those alternators and idler pulleys, that is really what you want to do.

What have you done to maximize your on-hand inventories and what, if any, protocols have you put into place to monitor those for viscosity, etc.?

Ben Kopp: For our standard fluids, we have not really changed our typical policy. We are going through less fluid, so we are just not buying as often. Maybe some of the larger shops that are not running have reduced their quantity on-hand of oil. We have not changed anything with our anti-freeze, partly because of how we order anti-freeze and how we get it delivered. It stays in a sealed container until it is poured into our units. With DEF, our biggest priority is reducing the bulk on-hand. 

Dany Landry: Something for everyone to think about for when you do have those bulk containers or bulk fluids: everything has a shelf life. If oil is in the original container and is properly sealed, engine oil shelf life is about five years. Under similar conditions, DEF’s shelf life is only about a year. If it is out in the sunlight or weather conditions, it is going to degrade more rapidly. Coolant can stay indefinitely, as long as it is stored correctly in the original container. Once you start mixing coolant, or if you buy coolant pre-mixed, it will last for a good five to 10 years. However, many people mix coolant incorrectly by using tap water instead of distilled water. That coolant will degrade much faster. 

Are there any special considerations in the wintertime, in terms of fuel additives or fuel blends?

Derek Brown: I would go to my fuel vendor and make sure the fuel is treated according to what I need and for the environmental conditions that I am operating in. I would also recommend getting that fuel in the vehicle and operating the vehicle, so it is in the lines, the engine, return line, pre-heater, etc., so all those components have treated fuel reaching them. I would also like to touch on what you were discussing earlier with the belts and pulleys. I find it to be a good idea, if a vehicle has been sitting for a long time, to have the engine started from the rear. Then if an alternator or pulley is seized or partially seized and would wipe out a belt, you are right there to see it immediately and can shut the engine off before it causes more damage.

Over the past several months with COVID-19, various types of protection have been added to vehicles. How would you suggest adding these to your typical PM program for the short-term and the long-term?

Derek Brown: Make sure that whatever systems you have in place are operational. If you have a UV light that comes on with the evaporator motor, for example, make sure that it does come on and that the light does work. Ensure that filters and ionization systems are functioning. After a trip is completed, bring the vehicle into the shop and operate these devices on a trip-by-trip basis. Make sure these systems work for when you are ready to put the vehicle back in service.

For coaches that are parked, is keeping them completely dry the best option? 

Robert Hitt: Yes, keep them empty and keep them dry. Many different manufacturers have water shut-off valves. We use the coolant from the engine to make sure that we keep the fluid thawed. In different regions, we have seen that actually be the cause of a coolant leak that the customer could not find. He could not figure out where a gallon of anti-freeze was going every time a bus went out. Where it was going was actually to that heater loop in the toilet tank. It had a small pinhole in it, causing his coolant leak. 

Make sure those valves are open if you are exercising and operating the coach. Even though we do not have any fluid in there, we want to keep them in the loop and keep it circulating.