C/K trucks built after October 31, 1989, have the orifice tube located in the condenser outlet pipe. The orifice tube, part #3096068, is unique for this application and can be easily identified by the black colored inlet end.
Parts are currently available through GMSPO.
Special caution must be used in servicing and replacing the orifice tube. This new orifice tube is black and white, and the black end must be inserted into the condenser outlet. Do not use the old all white orifice tube for trucks built after the following VIN breakpoints listed below. For trucks built before the VIN breakpoints listed use P/N 3033879.
Fort Wayne - LZ140485
Pontiac East - LE132779
Oshawa - L1126075
Failure to use the correct orifice tube or follow proper installation of the new tube may result in restriction of the liquid line and subsequent replacement of the liquid line.
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.