GM Service Manual Online
For 1990-2009 cars only

The efficient operation and life of the air conditioning (A/C) system depends on the chemical stability of the refrigeration system. Contamination with dirt, air, or moisture leads to chemical instability and results in the following conditions:

    • Unstable pressure-temperature relationships
    • Reduced efficiency
    • Interior corrosion
    • Premature component wear
    • Premature component failure

Observe the following general practices in order to ensure the chemical stability of the system:

    • Before breaking a refrigerant connection, wipe away any dirt or oil. This will reduce the risk of contamination. Immediately cap, plug, or tape both sides of the connection.
    • Keep all tools clean and dry including the manifold gauge set and any replacement parts.
    • When adding polyalkaline glycol (PAG) refrigerant oil, ensure that the transfer device and the container are clean and dry. Refrigerant oil must be as moisture-free as possible.
    • Set up all of the necessary tools, cleaners, etc., before opening the A/C system. Do not leave the A/C system open any longer than is absolutely necessary.
    • Evacuate the A/C system after opening and before recharging the system.