EVAPORATOR O-RING AVAILABILITY
In addition to the Standard evaporator outlet O-Ring (P/N 3053204, .549" ID) there is a thicker outlet O-Ring (P/M 3090774, 3/4") available through GMPD. This thicker O-Ring may be used on the evaporator outlet fitting in cases where the standard O-Ring does not provide a sufficient seal. Either of the outlet O-Rings maybe used in conjunction with the inlet O-Ring (P/N 3053203, .364" ID) at the evaporator block fitting.
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.