GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2000 🢒 GMC K Pickup - 4WD 🢒 HVAC 🢒 Heating, Ventilation and Air Conditioning 🢒 Handling of Refrigerant Lines and Fittings
    • Ensure that the metal lines do not exhibit the following conditions.
        This will prevent the loss of system capacity due to line restriction:
       - Dents
       - Kinks
    • Do not bend the flexible hose line to a radius of less that 4 times the diameter of the hose.
    • Do not allow the flexible hose line to come within a distance of 63.5 mm (2 ½ in) of the exhaust manifold.
    • Inspect the flexible hose lines regularly.
        Replace the flexible hose line with new hose if one of the following conditions exist:
       - Leaks
       - Brittleness
       - Deterioration

Object Number: 221228 Size: SH
    • Proper O-Ring Installation

Object Number: 221226 Size: SH
    • Improper O-Ring Installation
    • Before disconnecting any fitting in the refrigeration system, discharge all of the Refrigerant-134a. Refer to Refrigerant Recovery and Recharging .
    • Once you open a refrigerant line to the atmosphere, cap or tape the line immediately.
        This will prevent any of the following items from entering the line:
       - Moisture
       - Dirt

Object Number: 3576 Size: SH
    • Use the proper wrenches when you make connections on the O-ring fittings.
        Back-up the opposing fitting with a wrench in order to prevent distortion of the following areas:

Object Number: 3578 Size: SH
       - The connecting lines
       - The components
    • Tighten all of the tubing connections to the specified torque.
        Too much or too little torque may result in the following conditions:
       - Loose joints
       - Deformed joint parts
       - Refrigerant leakage
       - An inoperative A/C system
    • Ensure that the O-rings and the seats are in perfect condition.
        A burr or a piece of dirt may cause a refrigerant leak.
    • Install new O-rings that you have lubricated with the mineral base 525 viscosity refrigerant oil.
        Do not use polyalkylene glycol (PAG) synthetic oil.
        Do not wipe the threads with a cloth.
    • Keep PAG synthetic refrigerant oil off fitting threads. Long term contact of PAG synthetic oil on threads may cause future disassembly difficulties. Flush threads of fitting with mineral base 525 viscosity refrigerant oil. Do not use PAG synthetic oil. Do not wipe threads with a cloth.