K Yukon/Denali 4WD V8-6.5L DSL Turbo VIN S (1999)
A/C Coupler O-ring: Description and Operation
Install new GM-approved service replacement air condition O-ring seals whenever a joint or fitting is disassembled, except when the O-ring seals are
provided on new replacement components. Without using the replacement O-ring seals bearing the specified part numbers, heavy leakage of Refrigerant
-134a may occur. The part number will provide identification.
Coat the air conditioning O-ring seals with 525 viscosity refrigerant oil just before installation. Slip the O-ring seals onto the flange tube in order to
ensure the proper location and seal. In order to prevent the possibility of swelling and a reduction in the sealing effectiveness, do not soak the O-ring
seals in refrigerant oil. Prior to installation, examine the O-ring seals and the fittings in order to make sure the O-ring seals do not have nicks or
deformities. Replace any nicked or deformed parts in order to prevent refrigerant leakage.