some people have said you should and others have said you dont have to. I myself have never put antifreeze in the during installation in all the years i have worked on cars
No. The antifreeze has to be mixed with the water before the water freezes.
will change the boiling and freezing point of the water
Almost all of it, yes.
The corrosion protection package in the antifreeze does " wear out " so if you do not change the antifreeze / preferably distilled water mix the coolant mix will become acidic and not provide the corrosion protection that is required
If you have water instead of antifreeze in your cooling system, it will freeze! You won't be able to start the car, because the engine is connected to the water pump (which won't be able to move). If you have nothing in your cooling system (no water, no antifreeze, nothing else), then you need your head checked. Your car won't start either.
Change the head gasket.
Most antifreeze is the same. You can use any brand of automobile antifreeze; even the cheap stuff. Just remember to make it into a solution of 50% antifreeze to 50% water before putting it in your car.
Yes. Never add pure antifreeze. Pure antifreeze will actually freeze before a 50/50 mix. Add coolant that is a 50/50 mix of antifreeze and distilled water. You can buy it already pre-mixed.
The weep hole is "an indicator of bad bearings and/or seals" in the water pump when antifreeze starts to drip or run out of it. If antifreeze is coming out the weep hole, change the water pump.
=To properly flush the antifreeze on a 2002 Yukon you will need a antifreeze vacume system you will need to start the car and have it running turn on all the heating modules to high and have the car reved at about 1.5 r.p.m, or a little higher to activate the vaccume this will start sucking the old antifreeze out. When the radiator is empty{you will know when it is empty because there will be no more antifreeze coming out}you can then fill it up with half and half antifreeze[half water half antifreeze].=
It chances the boiling point of the water, and it changes the freezing point of the water
Usually a 50 / 50 mix of antifreeze and distilled water for year round use to provide corrosion protection , freeze and boil over protection . In colder climates , Ford states not to exceed 60 % antifreeze . The corrosion protection " portion " of the antifreeze does wear out so follow the suggested change intervals for the type of antifreeze that is required for your vehicle