There may be some confusion about the orifice tube location on 1992 C/K trucks built at the Janesville assembly plant. The orifice tube on vehicles with C60 (front A/C only) is located in the condenser outlet tube where it attaches to the liquid line. On vehicles with rear A/C (C69) the liquid line is split at a junction block. One side of the split goes to the evaporator inlet while the other goes to the thermal expansion valve for the rear evaporator. The orifice tube for these units is located on the evaporator side of the liquid line about three or four inches from the junction block. There is an access fitting provided here for orifice tube cleaning or replacement.
Condensers for use on rear air models have a crimped outlet tube so that an orifice tube cannot be installed. Since the condensers are otherwise identical, it is possible for a C69 condenser to be installed in a C60 vehicle. If this occurs, it will be necessary to replace the condenser.
C60 C69 --- --- Condenser 52455855 52457411
Orifice Tube 3033879 (White) 3096068 (black/white)
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.