How to Pump a Tire

Jack the tire up so that it is off the ground and not supporting the weight of the car. It will make the process go faster and allow the battery-powered air compressor to do its job without any undue strain.

Remove the plastic valve cover from the tire you want to pump up. It is usually very small, so you should put it in your pocket or a similar safe place lest you lose track of it.

Push the valve from the air compressor onto the tire valve. It should slip firmly into place over the threaded tip of the valve. Push down the thumb latch on the compressor's valve to complete the seal and allow the air to go into the tire.

Turn the pressure gauge knob on the air compressor until it reaches the appropriate pressure for your tire. You can find the recommended tire pressure in the vehicle's owner manual or use a reading you take with a pressure gauge from one of the car's inflated tires.

Connect the battery-powered air compressor to the battery. This can usually be performed with an extension cord connecting to the cigarette lighter (included with most compressors), though exact details may vary by model.

Turn on the switch and let the compressor do its work. Monitor it as it pumps up the tire. Some compressors are designed to turn off once they have reached the desired pressure, but others must be turned off manually.

Uncouple the air compressor's valve from the tire and replace the tire's valve cover.

Lower the jack until the tire is once more supporting the car.