GM Service Manual Online
For 1990-2009 cars only

DIESEL TRANSFER PUMP COVER DAMAGE WARNING

WE HAVE RECEIVED REPORTS CONCERNING DAMAGE TO THE TRANSFER PUMP COVER ON THE INJECTION PUMP. WHEN REMOVING THE INJECTION LINES IT IS IMPORTANT THAT YOU DO NOT DAMAGE THE TRANSFER PUMP COVER (BLACK IN COLOR) WITH THE WRENCH. IF THE COVER IS DAMAGED (A DIMPLE OR CRACK) IT COULD CAUSE THE INJECTION PUMP TO ALLOW AIR TO ENTER THE SYSTEM CAUSING ROUGH IDLE.

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.