Basics when working on R-134a refrigerant system

• Keep work area and all tools clean.
• Use only tools, equipment and parts specified for use with R-134a.
• Always wear protective glasses and gloves when working on A/C system.
• Switch on existing exhaust/ventilation systems when working on the refrigerant system.
• Discharge A/C system before removing any refrigerant system component.
• Always use an Underwriter's Laboratory (UL) approved refrigerant recovery/recycling /recharging unit such as Kent-Moore ACR4, or equivalent, whenever discharging an R-134a A/C system.
• Immediately plug open connections on A/C components to prevent dirt and moisture contamination. Likewise, DO NOT remove new component from packaging until ready to install. Immediately tighten component connections after installation.

• Always replace O-rings, DO NOT reuse. Use only the correct size and type of O-rings specified for use with R-134a refrigerant. Lubricate O-ring with refrigerant (PAG) oil before installing.
• Use only the specified PAG oil from a sealed container and ALWAYS reseal oil container immediately after use. DO NOT use oil if it has become contaminated with moisture or if the container has been left open.
• Always reinstall cap(s) over A/C service valve(s).

Flush refrigerant system with compressed air and nitrogen (available locally) if:

• Moisture or dirt have entered the refrigerant system (i.e. following an accident).
• Refrigerant oil is dark and thick.
• Too much refrigerant oil is in the system following compressor replacement.
• The compressor is replaced due to internal damage (i.e. noises).

When flushing the refrigerant system:

• DO NOT top-off a charged refrigerant system. Instead, discharge, evacuate and recharge the system.
• After system recharge, manually rotate A/C compressor approx. 10 turns before starting engine. Start engine with A/C OFF. After idle speed has stabilized, switch A/C ON and let engine idle (compressor running) for a minimum of two minutes before raising engine speed.