1997 Chevrolet Astro Owner's Manual - Page 314

Finish Damage Any stone chips, fractures or deep scratches in the finish 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 other service outlets. Larger areas of finish damage can be corrected in your dealer's body and paint shop. 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 to the owner, the surfaces of new Underbody Maintenance vehicles damaged by this fallout condition within m of Chemicals used for ice and snow removal and dust control 12 months or 12,000miles (20 000 k ) purchase, whichever occurs first. If can collect on the underbody. these are not removed, accelerated corrosion (rust) occur on the underbody can 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 debris can collect. Dirt packed in closed areas of the frame should be loosened before being flushed. Your dealer or an underbody car washing system can do this for you.