Technician Handbook Air Conditioning for Collision Repair Prevent Contamination Open AC systems are sensitive to contamination and can absorb water from the air. When disassembling AC systems, seal off all open components to prevent contamination. Contaminants Contaminants include: • Grinding debris • Welding debris • Sanding dust • Moisture (water) • Engine Coolant 18 Collision Repair & Refinish Training