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A/C Recharge

  • A/C systems do NOT consume refrigerant — if it’s low, there’s a leak
  • Find and fix the leak before recharging
  • Common leak points: compressor shaft seal, O-rings at connections, condenser
  1. Connect manifold gauge set to high and low side ports
  2. Start engine, turn A/C to max cold, max fan
  3. Check pressures against specifications
  4. Add R134a refrigerant as needed
  5. Do NOT overcharge — damages the compressor
  • Low side: 25-45 PSI (running, A/C on)
  • High side: 150-250 PSI (varies with ambient temperature)

A proper A/C service includes:

  • Recover existing refrigerant
  • Vacuum test for leaks
  • Evacuate system (30+ minutes vacuum)
  • Recharge with exact amount by weight
  • Add correct amount of PAG oil
  • UV dye for future leak detection