1997 GMC Suburban Owner's Manual - Page 341

Tires To clean your tires, use a stiff brush with a tire cleaner. Underbody Maintenance Chemicals used for ice and snow removal and dust control can collect on the underbody. If these are not removed, accelerated corrosion(rust) can occur onthe underbody parts such as fuel lines, frame, floor pan and exhaust system even though they have corrosion protection. At least every spring, flush these materials from the underbody with plain water. Clean any areas where mud and other debriscan collect. Dirt packed in closed areas of the frame should be loosened before being flushed. Your dealer oran underbody car washing system can do this for you. NOTICE: When applying a tire dressing always take care to wipe off any overspray or splash from all painted surfaces on the body or wheels of the vehicle. Petroleum-based products maydamage the paint finish. Sheet Metal Damage If your vehicle is damaged and requires sheet metal repair or replacement, make sure the body repair shop applies anti-corrosion material to the parts repaired or replaced to restore corrosion protection. Chemical Paint Spotting Some weather and atmospheric conditions can create a chemical fallout. Airborne pollutants can fall upon and attack painted surfaces on your vehicle. This damage can take two forms: blotchy, ringlet-shaped discolorations, and small irregular dark spots etched into the paint surface. Although no defect in the paint job causes this,GM will repair, at no charge tothe owner, the surfaces of new vehicles damaged by this fallout condition within 12 months or 12,000 miles (20 000 km) of purchase, whichever occurs first. Finish Damage Any stone chips, fractures or deep scratches the finish in should be repaired right away. Bare metal will corrode quickly and may develop into a major repair expense. Minor chips and scratches can be repaired with touch-up materials available from your dealer or otherservice of outlets. Larger areas finish damage can be corrected in your dealer's body and paint shop. 6-59