1. Pull your car onto a level surface in the shade.
2. Remove dust caps from the tires' valve stems.
3. Using your tire gauge, firmly press the tip of the gauge straight on to the tire's valve stem for a brief moment.
4. The tire gauge should provide a psi reading; if the number seems unrealistically low or high — for example, 85 psi or 1 psi – you will need to repeat the previous step, ensuring that the tire gauge's tip is properly making contact with the valve stem.
5. If the tire gauge's recorded reading is higher than the manufacturer-recommended rating, press the gauge tip on the valve stem until you hear air leak out. Check the tire pressure again.
6. If the reading is lower than recommended, fill the tire with air by firmly pressing the air-hose tip onto the valve stem. You will hear air quietly enter the tire. If you hear air leaking or spraying out, you need to double-check that the connection between the air hose and the tire’s valve stem is secure.
7. When you think you've added or let out enough air, check the pressure a few times with the gauge.
8. Replace the valve dust caps. Rastetter emphasized the importance of keeping dust caps on during winter driving because if water gets into the valve stem and freezes inside the tire, it could cause a flat.