The breaking or coming off of accessory drive belts on some subject vehicles mav be due to a mismatching of the water pump and crankshaft pulley diameters. This can cause one (1) of the belts to drag in it's groove as the mismatched system tries to drive the belt at two (2) different speeds.
If the above condition is encountered, verfiy that the correct pulleys have been installed by referring to the illustration.
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.