How Long Do Fire Engines Last?

The latest on this, is that an outside mechanic feels the brakes 9air) failed due to ice in the lines. It has been very cold here lately (daytime highs in the low 20’s). I recall that show about the Ice Road truckers-brake failures due to freezing was common. My question: aren’y firetrucks kept in heated garages? Also, how does moisture neter the brake system?

Being stored in a heated garage has nothing to due with it. The truck uses the stored energy from the system storage and the compressor (engine mounted) replenishes the air from atmospheric air(dew point is?).
Most modern air systems have a desiccant type air dryer in the system that is very effective at removing the majority of water in the compressed air. However the air reservoirs(tanks) must be checks and drained by the operator. On an older system without an air dryer like my 1991 truck I must daily drain the moisture accumulated in the tanks of witch I have 3.
On trucks with air dryers no moisture is seen when the dryer is working properly, but when the dryer becomes overused or malfunctions water can and will build up and if not checked will cause frost in the valves even in above freezing temps.

It can also be said that inside storage can increase problems with moisture as warm air will hold more water than cold air.

Also a fire truck with air brakes will have a secondary source of air in either an onboard electric compressor or a shore line to another compressor system.
That way when the call comes in the truck is ready to roll without having to build air to release the parking brakes, and use the service brakes.

You obviously have no idea how park works on the car. If you are traveling at any rate of speed above the rate of a walk, all putting the car in park will do is scatter metal chips in your automatic transmission. This is considered a bad thing.
It will not slow you down. You could probably slow down more if you just forced the door open against the wind resistance. Or drag your feet.

My old HS buddies would perform “drop reversals” in cars built in the 80’s.
Even in the cheaper cars, the tranny survived and continued to give service after multiple abuses.
One car I do remember having a safety is the Ford Maveric, which had a tendency to jump gears all by itself.

For those who have never abused their car, a drop reversal is simply, at speed, you drop the tranny into reverse, punch the gas. This does not work on a manual at all.

When my master cylinder on my Dodge Dart broke off while driving I punched reverse, breaking the reverse gear, but the shock took a lot of momentum away leaving me able to to high center the beast on the over sized curb in that area.