Stylus Pro 4880 Field Repair Guide 1/17/08
Pump and Cap Installation Printer Component, Software Item, LCD Display, Printer Button  Page 94.
10. Replace the Trigger Spring.
11. Replace the Trigger Assembly End Piece.
12. Perform Reset When Cleaning Unit Change (if the Cap/Pump Assembly was changed).
Spring goes here.
Ensure that the Splash 
Guard is routed as shown.
Trigger Assembly End Piece here