You took the whole tractor in? Must have been a rear. I just threw my front tire in the pickup and took it to the tire store.
If it was a rear, it must not be fluid loaded.
Some folks weld little metal stubs in front and behind the valve stem to protect them. Probably not a bad idea for those of us who use our machines like dozers. But, they can make checking air pressure and filling the tires a real pain.