1992-2025 Toyota Acid Rain Damage Repair TSB

Acid rain damage is a common issue affecting vehicle paint finishes, especially in areas with industrial pollution. This Technical Service Bulletin (TSB) T-SB-0035-24 Rev2 from Toyota provides comprehensive guidance for identifying, preventing, and repairing Toyota acid rain damage on a wide range of models from 1992 to 2025.

Symptoms of Acid Rain Damage

Acid rain results from acidic compounds in rainwater or airborne moisture settling on a vehicle's surface. These compounds can cause significant damage to painted surfaces, particularly horizontal areas like the hood, roof, and decklid. The damage typically appears as stains on the paint that resemble hard water spots.

Unlike ordinary water spots, these acid rain stains cannot be removed with regular washing. Acid rain can also etch and soften the paint, making standard buffing or polishing procedures ineffective and potentially causing further damage or visible depressions in the paint.

Diagnosis and Severity

Toyota categorizes acid rain damage into three levels of severity:

• Minor damage: This level of damage typically only requires buffing for repair.
• Moderate damage: This usually necessitates neutralizing the affected area, followed by color sanding and buffing.
• Severe damage: This indicates damage extending beyond 1/2 mil of the clearcoat on pearl, metallic, or solid colors. Repair for severe damage involves neutralization, sanding, and repainting.

Determining the exact depth of acid penetration, especially for moderate or severe damage, often requires color sanding a representative area and measuring the paint removed with a magnetic or digital film thickness gauge. These procedures should only be performed by qualified body/paint technicians.

Important Warnings for Owners

Toyota highlights several critical warnings to prevent further damage during repair or maintenance:

• "The following process can be followed but with matte paint finish safe products ONLY. Using materials listed in this document can lead to paint damage to matte paints."
• "To minimize the possibility of burning through or hazing paint surfaces, the following buffing procedures should be performed only by personnel experienced in rotary power buffing."
• "NEVER use different buffing/polishing compounds on the same pad."
• "Use only LIGHT pressure on the buffer to prevent burn-through damage to the paint surface."
• "While it is recommended to sand down into the primer coat, the underlying electro deposition coat should NOT be exposed, since it provides essential corrosion protection."
• "ALWAYS sand in one direction and never in a circular pattern."
• "lacquer-type paint is NOT recommended for this application."
• "Check with state and local ordinances regarding the use and disposal of all chemicals."

Repair Procedure Summary

The TSB outlines specific repair procedures based on the severity of the Toyota acid rain damage:

For Minor Damage:

1. Move the vehicle out of direct sunlight to cool the paint surfaces.
2. Wash the vehicle with automotive liquid soap and water once surfaces are cool.
3. Neutralize any remaining acid with a solution of one tablespoon of baking soda per quart of water, applied with a plastic garden sprayer.
4. Rinse the vehicle thoroughly with fresh water.
5. Measure paint film thickness in several locations and record them.
6. Buff affected areas using the least aggressive pads and liquid compounds. Periodically measure paint film thickness during buffing. Buffing should resolve the issue within approximately 30 minutes per vehicle.

For Moderate Damage:

1. Follow steps 1-5 for minor damage (cooling, washing, neutralizing, rinsing, measuring paint thickness).
2. Mix liquid automotive washing soap in a pail of clean water and immerse recommended wet-dry sandpaper (e.g., #1500 or #2000 grit) to soak for several minutes.
3. Carefully color sand affected paint areas using the wet-dry sandpaper with a soft foam rubber sanding pad. Frequently apply clean water and wipe down sanded areas to check for spot removal.
4. Continuously measure paint film thickness during sanding to prevent excessive removal, removing no more than 1/2 mil of clearcoat.
5. Install recommended buffing pads and set buffer speed to 1200–1800 rpm. Apply buffing/polishing material sparingly and buff until haze is almost gone.
6. Inspect for remaining acid spots; re-sand and polish if necessary. Achieve a high-gloss finish.

For Severe Damage:

If acid damage has penetrated more than 1/2 mil on metallic, pearl, or solid colors after color sanding, repainting is required.

1. Wash the vehicle surface with mild automotive soap and water, then rinse with deionized water. Clean affected areas with an appropriate silicone/wax remover.
2. Completely sand the affected areas with a dual-action sander to eliminate depressions. Sand down to the primer coat, but do not expose the underlying electro deposition coat.
3. Finish sanding with wet-dry sandpaper of the grit recommended by paint manufacturers.
4. Wash and rinse the vehicle again with mild automotive soap and deionized water.
5. Clean sanded areas with an appropriate silicone/wax remover.
6. Apply a quality urethane enamel color coat or base coat/clear coat as required for maximum repair durability. Follow the paint manufacturer's recommendations for application.

Required Tools and Materials

To address Toyota acid rain damage, technicians will need specific tools and materials, including:

• Liquid Automotive Washing Soap, Baking Soda, Water Pail
• 3M™ Finesse-It™ II Machine Polish (or Equivalent)
• 3M™ Perfect-It™ System (or Equivalent)
• 3M™ Finesse-It™ II Wool Pad (or Equivalent)
• 3M™ Perfect-It™ Foam Pad (or Equivalent)
• #1500 or #2000 Grit Wet-Dry Sandpaper (pre-soaked)
• Variable Speed Rotary Buffer (1200–1800 rpm)
• Elcometer® 211 Mechanical Coating Thickness Gauge, Magnetic (or Equivalent)
• Fischer® Deltascope DMP30, Digital (or Equivalent)

Owner Action and Prevention

Owners of 1992-2025 Toyota vehicles should be aware of the potential for Toyota acid rain damage. To minimize exposure and prevent damage, frequent vehicle washing is recommended, especially during periods of high heat and humidity. This is particularly important in geographical areas known for high concentrations of acid rain and industrial fallout.

If you notice stains resembling hard water spots that do not wash off, it is advisable to consult a qualified Toyota service center. Inexperienced personnel should not attempt these repairs, as improper techniques can cause further damage to the paint finish.

Warranty Information

The TSB indicates that this repair is "Not Applicable to Warranty" (N/A) under the warranty information section. This suggests that repairs for acid rain damage are typically not covered under standard vehicle warranties.

NHTSA ID: 11012742