Main Pump: Disassembly
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.
Remove main pump wear plate. See Fig 1. Remove drive gear and driven gear, keeping gear orientation as originally installed. Remove main pump "O" ring.