Here's something you need to check if you buy it.
There were a couple of years there that the white plastic antifreeze tanks were made of bad plastic that didn't hold up the e gine heat well. They developed a lot of spider heat cracks and then started leaking.
The tank is located on top of the right corner of the radiator. If it looks new then it's probably been changed. If it has cracks, change it before you load the closet as everything has to be unloaded from it.
If you have to change it, I'd recommend having Freightliner flush the cooling system and install their long life coolant good for 6 years or 600,000 miles.