When referring to the Service Manual Brake System Diagnosis Chart, "Restricted Brake Fluid Passage", an additional area to inspect is the Banjo Bolt, which attaches the brake hose to the caliper. This bolt has a through hole to allow the flow of brake fluid from the brake hose to the caliper. Should the hole be obstructed or mislocated, not drilled in the non-threaded area, fluid flow could be restricted and not allow the caliper to function properly.
Whenever this bolt is serviced both copper seals must be replaced and the system must be re-bled.
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.