NHTSA Service Bulletin 11007443: 2000-2025 Scion 4runner

Acid rain results from rainwater or other airborne moisture that become acidic due to industrial chemical impurities in the atmosphere. If these acidic compounds settle on an exposed vehicle, especially the horizontal areas such as the hood, roof, and decklid, significant damage to the painted surfaces can occur. Acid rain damage can typically be identified on vehicles by the presence of stains on the paint surface that resemble hard water spots. Unlike water spots however, acid rain damage cannot be removed by regular washing procedures. Also, because acid rain can etch and soften the paint, normal buffing or polishing repair procedures should not be attempted. This can cause further damage and result in visible depressions in the paint surface. The following are the three major categories of acid rain damage: Minor damage: requires only buffing to repair. Moderate damage: usually requires neutralizing, color sanding, and buffing. Severe damage: extending beyond 1/2 mil of clearcoat on a pearl, metallic, or solid color, requires neutralization, sanding, and repainting. In cases where acid rain damage is minor, neutralization and buffing with a liquid-type paint finessing product may provide an adequate repair. Only specially formulated products outlined in this bulletin should be used for that purpose. Unfortunately, other than minor damage, there is no simple method of determining the actual extent (depth) of acid penetration other than color sanding a representative affected area until there is no visible etching or depressions, followed by measuring the amount of paint removed with either a magnetic or digital-type film thickness gauge. The procedures in this bulletin are intended for use by qualified body/paint technicians and should not be attempted by inexperienced personnel. It is the dealers responsibility to protect and maintain the quality of the vehicles paint finish after receipt at the dealership prior to the first sale. Perform frequent vehicle washing, as often as daily, during high heat and humidity periods to minimize the potential for paint damage due to acid rain exposure. This is especially important in geographical areas known for high frequency and concentration of acid rain and industrial fallout.