2002 GMC Savana Van Owner's Manual - Page 311

How to Check Use a good quality pocket-type gage to check tire pressure. You can't tell if your tires are properly inflated simply by looking at them. Radial tires may look properly inflated even when they're underinflated. Be sure to put the valve caps back on the valve stems. They help prevent leaks by keeping out dirt and moisture. The purpose of regular rotation is to achieve more uniform wear for all tires on the vehicle. The first rotation is the most important. See "Scheduled Maintenance Services" in the Index for scheduled rotation intervals. Tire Inspection and Rotation Tires should be rotated every 6,000 to 8,000 miles (10 000 to 13 000 km). Any time you notice unusual wear, rotate your tires as soon as possible and check wheel alignment. Also check for damaged tires or wheels. See "When It's Time for New Tires" and "Wheel Replacement" later in this section for more information. Make sure the spare tire is stored securely. Push, pull, and then try to rotate or turn the tire. If it moves, use the ratchet to tighten the cable. See "Storing a Flat or Spare Tire and Tools" in the Index. If your vehicle has dual rear wheels, also see "Dual Tire Operation" later in this section. If your vehicle has single rear wheels, always use one of the correct rotation patterns shown here when rotating your tires. 6-44