Main Pump: Notes
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, 2003 Chevrolet Cab & Chassis Silverado, and 2002 GMC Sierra. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Main pump may also be referred to as the charging pump. The main pump drive gear and driven gear have a punch mark on one side. Before these gears are removed from the main pump, the presence or absence of the punch marks must be noted so the gears can be reinstalled in their original orientation.