Put fuel stabilizer in your gas tank and run each car for 5-10 mins let it get through entire fuel system. I would also leave a battery tender on each make sure the batteries are good when you return. And check coolant levels should the garages get below freezing in the winter. Consider possible power outages during the winter. Don’t want them to freeze up. 

See below:

https://m.youtube.com/watch?v=PvgeRq6Ptwg

what street? ...

so I can check if they're still there 😛  

Out of my 20+ years experience of having one of my cars standing for the most part of the year:
1) you might want to fully charge and disconnect the car battery (although I am not disconnecting it, since I prefer to have the car constantly connected to a wall-mounted battery charger, which has a Battery Maintain mode, via a self-installed external connector - IMO this is the better way, since battery disconnection resets the ECU and in some cars locks the multimedia system so that a dealer code might be needed to reenable it);
2) install a WebCam in your garage;
3) I personally do not bother adding any fuel stabilizers and never had problems (though I know that they exist and are supposed to help) - but usually I make sure that the car has like 1/4 of fuel left in the tank when I depart, and then fill it with fresh fuel soonest upon my return;
4) If outside the city, install an ultrasonic pest repeller in your garage. Helps a lot against rat nests under the hood etc.;
5) Do not bother putting your car on blocks "to keep tires round". Never did that in 20 years, and never had tire roundness problems afterwards. Out of my experience quality tires are elastic enough to not deform even when left standing for an entire year. And IF (which never happened to me, but still) they do deform, for me it would be a sign that their material degraded and that it might be the time for new tires (because safety);
6) I personally do not use car covers, cause some not-so-good-quality covers, when left on a car for a really long time, may leave marks on the clear coat, and these marks may be hard to get off. For me, it is better to have a dusty car upon my return, than to have to polish things off a non-dusty one. I´ve been there.
7) If you have a remote start feature which works via GSM or the Internet, you might want to remotely start your car(s) every couple of months or so, to keep the engine internals oiled.
8) Don´t forget, that regardless of your presence or absence, and even if mileage is extremely low, engine oil has to be replaced latest 1 year after the previous change;
9) I personally also unscrew the radiator cap slightly, so that temperature changes-related pressure fluctuations do not stress the cooling system in my absence, but that´s just me. If you are like me, do not forget to tighten it upon your return.
10) Make sure no food or drinks or items which may go bad are left in the car(s).
That is all I can think of right now. Good luck with your family business!

Hey @mountainmanjoe,

If you know what street CarlJason98 lives in, you should put a camera in the garage without him noticing lmao. 🤣 

Make them secured for your peace of mind 😁

Sta-bil Marine is pretty good.

Should you put the cars up on blocks to save the tires?

Don't know, just a thought

I tend the have the same question as mittegag. I think up on blocks would help preserve the tire roundness. 

Posted by: @mendia

↑

I preciate the tips you provided. So 2000 Chevy Silverado 1500’s don’t have radiator caps, Are the Fluctuations going to still be a concern or is there another way to allow those fluctuations? I’m going on deployment very soon and my wife is going to be home to be able to take care of my baby

Your vehicle must have a coolant cap somewhere since there needs to be a way to fill and bleed the cooling system. If the radiator itself has no pressure cap there would usually be one on a pressurized expansion tank. I've never had a cooling system issue due ambient temperature variation with cars that hibernate during the winter and there are some cars I've owned for over 30 years.

Also note this topic is over 3 years old, as is its latest response prior to yours. The issue of storing vehicles for a period of time has come up repeatedly here so you may want to use the site search function.

Posted by: @mendia

↑

Are the Fluctuations going to still be a concern

not at all. All cooling systems have pressure relief. It's usually printed right on the cap (15 PSI etc.)

The "fluctuations" during storage are nothing compared to normal cycles during regular use.