GM Service Manual Online
For 1990-2009 cars only

Install new approved service replacement air conditioning O-ring(s) and flat washers whenever a joint or fitting is disassembled.

Some vehicles use flat sealing washers and O-ring(s) to seal the refrigerant system. The flat washers are used on block fittings of refrigerant components. The O-ring(s) is used to seal the refrigerant tubes.

The O-ring fitting consists of:

    • An aluminum alloy, externally threaded fitting which is welded to an aluminum tube.
    • A free-spinning internally threaded nut.
    • An aluminum tube end which accommodates the O-ring(s).

Verify that the flat washers or O-ring(s) have not been damaged prior to installation. Replace damaged parts.

Coat O-ring(s) and flat washers with the approved refrigerant oil.

Failure to use the proper service replacement parts and procedures may result in a leak.

Service Caps Seal

The primary seal for the service ports is the sealing cap. The cap contains a specially designed O-ring or gasket which provides a leak free seal. Should the cap be loose, missing, or the wrong usage, a loss of refrigerant could result.