What’s one thing that can ruin anyone’s day, either on the road or in the field? It’s the last word any farmer wants to hear over the farm radio or cellphone: “Hey, I’ve got a flat tire on the combine.” The only thing that might be worse? Getting another call later: “Hey, there is a flat tire on the grain cart.”

Following this seven-step checklist developed by Firestone Ag won’t guarantee you never have a flat tire on the combine or grain cart. But Brad Harris, manager of global agricultural field engineering for Firestone Ag, says it should reduce the odds that a flat will catch you off-guard. These steps help tires wear longer and help you know when it’s time to replace a tire rather than push your luck.

Related: Help combine, grain cart tires last longer

You can find the checklist plus a short video explaining it online.

1. Check tire inflation pressure with a calibrated gauge. Use the owner’s manual or information from the tire company to determine recommended inflation pressure for the application. For Firestone tires, you can find an inflation calculator tool on the website. If available, use a digital tire gauge for more accurate readout.

2. Check tire sidewalls for cracks and cuts. Visually inspect the tire, and run the palm of your hand along the face of the tire in a circular motion. If all you find is a nick or two, the tire should still have plenty of use left in it.

3. Check tire tread depth. You can use a ruler or a special tool designed for measuring tread depth. Know what the depth of new tires of that size should be. If less than 20% of the original tread depth is left, Fischer recommends opting for new tires rather than risking downtime during the season.

4. Check tire tread for stubble damage. You may find some small nicks and cracks at the edge of the tread from stubble. The key is whether cords are showing, Fischer says. If cords aren’t visible, the tire should have life left in it.

5. Check tread-to-ground contact. This gives you a measure of whether the tire is underinflated, overinflated or about right. With an ion standard radial tire, if three lugs are contacting the ground, it may be underinflated. Conversely, if you can stick a finger between a lug and the ground on the first lug off the ground, it may be overinflated.

6. Check valve stems for cracks, corrosion and debris. If stems wear enough, you can develop a slow leak. Take time to make sure the valve body is tight against the tire frame using a wrench, and if a valve stem cap is missing, replace it.

7. Check lug nuts. Don’t assume every lug bolt and bolt fastening the tire to the rim is still tight. Check each one before you leave that tire and move on to another one.