If the surface is corroded or if the blades are damaged, replace the impeller

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyEvaporative Emission Control System (California
model only)
This system routes fuel vapors from
the fuel system into the running engine
or stores the vapors in a canister when
the engine is stopped. Although no adjustments
are required, a thorough visual
inspection must be made at the intervals
specified by the Periodic Maintenance
Chart.
Inspection
...
Coolant Reserve Tank Installation
Install the following to the coolant reserve tank [A].
Pad [B]
Gasket [C]
Cap [D]
Collar [E]
Install the coolant reserve tank and tighten the bolt [F].
Run the hoses correctly (see Cable,Wire, and Hose Routing
section in the Appendix chapter).
Fill the coolant reserve tank with ...
Electrical Wiring
Wiring Inspection
Visually inspect the wiring for signs of burning, fraying,
etc.
If any wiring is poor, replace the damaged wiring.
Pull each connector [A] apart and inspect it for corrosion,
dirt, and damage.
If the connector is corroded or dirty, clean it carefully. If it
is da ...