Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
41 00... Corrosion Protection
The products recommended by BMW are optimized with regard to corrosion protection.
1.0 Removing sealing materials:
- Do not burn off PVC material (sealing compound) with a gas burner or similar or heat to temperatures above 180°C. This would generate highly corrosive hydrochloric acid and release harmful fumes.
- The new lining does not form a satisfactory bond with burnt PVC material which means that subsequent sub-surface rust may set in.
Remove PVC material with a rotating steel brush, or heat PVC to maximum 180°C with a hot air blower and scrape off with a spatula.
2.0 Corrosion protection of sheet-metal parts:
All weld joints sealed off with body sealing compound in original state must be primed and sealed off again thoroughly after repairing. Replace damaged or removed antinoise compounds.
Concluding cavity protection is the most important part of all corrosion protection measures.
Use the cavity protection spray only for smaller-scale straightening work where the parts in question are easily accessible.
Use the HRS spray gun with pressure container for all other repairs. Cavity protection agent is available in different container sizes.
Use the relevant probes with tubes for the different cavity areas.
The best repair is worth nothing if the subsequent cavity protection measures are not conscientiously carried out.
2.1 Cavity protection of steel parts:
New doors and lids must be sealed with cavity protection agent after being painted.
New sheet-metal parts or cavities, weld seams and folds formed by new sheet-metal parts must be sealed with cavity protection agent after being painted.
The cavities affected must be sealed with cavity protection agent after all straightening work.
2.2 Cavity protection of aluminum parts:
New doors, lids and side panels made of aluminum are not sealed with cavity protection agent.
After all straightening work on aluminum components, the cavities affected must be sealed with cavity protection agent after being painted.
After all welding work (E52 only) on aluminum components, the cavities affected must be sealed with cavity protection agent after being painted.
Cavities, seams and folds formed from new sheet-metal parts must be sealed with cavity protection agent after being painted.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.