keep it simple

And also just because a tire is standing tall means no guarentee. A tire with fluid may stand somwhat tall, but still be low on air pressure. Many tires are tore to shreds by having fluid and runing low on air pressure. It will tell you this by a small sidwall bulge that experiance folks can pick up on.

However all and all you have good odds that you will have to check the air presure, and you simply have to check it at the valve stem. I guess I should state that it is best to not mess with it if your project is a hour from being done or so. If they look good wait untill a rain day so you can play games with it while it rains. Not exactly like if it ain't broke don't fix it, but a close second to that statment. After you get used to the tractor you can pretty much tell by looking. Running a low tire tends to flex or fold the rubber and this is what causes the tire failure. Some of the old farm mags had pictures showing the different problems.