Pretrip in Winter

I forget what the technical reasoning is behind that. Maybe because in the winter there is a lot more idling and risk of carbon monoxide entering the cab. Also I suppose the colder temps make the exhaust pipes contract more when you shut down and thus more prone to leaking.

 

I can rationalize that the above answer is correct.
I had problems with the exhaust where it connected to the filters. Lots of pressure when it goes into regen. Also in the cold. Everything falls apart. Comes apart. At 20 below, even the roads fall apart. I've experienced the danger of an exhaust leak under the passenger door of the cab.
Otherwise... Lots of problems with the air system, fuel system.
Fuel likes to gel up in the cold. Be careful. Stay on top of it. Use good additive. Having to change fuel filters due to gelling.... I know all about that.... Doh! You can build up condensation in tanks in the cold. Result is water in fuel or air lines. So make sure fuel tank is as full as possible if you're going to park for hours.
Air system. Just a little water/condensation in there will freeze up and stop you from starting out. I've learned that draining the air system when you park, helps. Also, adding fuel line antifreeze to the air tank helps. You'll have to build up all the air pressure when you start up. That's far less hassle than dealing with frozen air lines.

 

Why?

Because the metal expands when it gets warm or hot and contracts when it becomes cold which can cause the system to loosen up.

 

i concur. but it's always a good idea to take a look under the truck for any missing clamps that rust and fall off as well all year long.

when you see black soot at any of the joints, have it taken care of ASAP. day cab, sleeper, don't matter.

also, i'd recommend looking under the hood, and the firewall area for any missing body plugs, or cracks that can allow exhaust to enter from piping near the engine bay.

another thought, i have read where many drivers of sleeper trucks, take along a CO detector as well.

 

I know in the summer, my windows are always open, so no chance whatsoever of CO poisoning even if the exhaust looks like swiss cheese. In the winter, windows are more likely to be rolled up, keeping any toxic gasses that leak into the cab inside the cab with you.

 

If you are doing a proper pre-trip, seasons are irrelevant.

 

So is focusing on one area. Should be focusing on them all.

 

I was not trying to provide a test answer for you. My point is one of reality. Understand that there are always test questions that are irrelevant and incorrect when it comes to real world application. As far as your test goes, study, study and study some more, maintain that discipline and you will ace the test/s.