Part of car maintenance is to check the air pressure, known as psi (pounds per square inch), of tires regularly. It is a good habit to check the tires' psi levels monthly, and more often if there are known tire problems, according to Car Talk. Too-low pressure creates friction, and too-high pressure causes improper auto balance. Both these situations are less than ideal and can cause accidents. The most common way to check air pressure and fill car tires is with a gas-station air compressor. Fortunately, the task is simple enough for most drivers to perform regularly.
Select a specific date each month to perform an air-pressure check on all your tires. Mark this date on the calendar as a reminder.
Place a plastic zip bag and rag in the car the day to perform the maintenance. This will help you keep the stem caps together and your hands clean.
Drive up to the gas station's air compressor when the car is cool. Inaccurate psi readings result from warm tires because hot air expands. The air compressor is most often a small, square box mounted on a pole with the label "Air" on it.
Turn off the car's engine. Open the plastic zipper bag. To keep your hands cleaner, use a rag to remove each of the stem caps by turning counterclockwise until they slip off the valve stem. Place each stem cap in the zipper bag when you remove it.
Open the car's driver side door. Locate the sticker on the inside of the door panel. Determine the recommended psi for your tires. Close the car door.
Insert the proper amount of change into the coin slot on the air compressor unit. There should be a label that specifies how much money to insert. If there is no slot, the use of the machine is often free.
Unwind the air compressor hose from the machine. Pull the hose to the first tire.
Press the hose end to the valve stem on the tire. The tire gauge meter should eject with the psi reading.
Squeeze the handle or trigger on the end of the hose near the connection piece. The air compressor should make a noise to indicate it is on. Press the connection firmly into the valve stem and watch the psi meter. Take the air compressor hose off the tire when the psi meter reading matches the recommended psi level.
Repeat the two previous steps with each of the tires. Rewind the air compressor hose back to the unit. Most units shut themselves off after a limited amount of time.
Take a stem valve cover from the plastic bag. Place the cover back on the stem of the tire and turn clockwise, creating a snug fit. Repeat with each tire.
