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

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyIdle Speed Control Valve Actuator Installation
Replace the O-ring [A] with a new one.
Apply engine oil to the new O-ring.
Install the idle speed control valve [A] as shown in the
figure.
10° [B]
Tighten:
Torque - Idle Speed Control Valve Actuator Retainer
Screws: 2.06 N·m (0.21 kgf·m, 18 in·lb)
Install th ...
Intake Air Temperature Sensor Output Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
Disconnect the intake air temperature sensor connector
and connect the measuring adapter [A] between these
connectors as shown in ...
Front Master Cylinder Removal
Remove the reservoir mounting bolt and nut [A].
Unscrew the banjo bolt [A] and disconnect the brake hose
from the master cylinder (see Brake Hose and Pipe Replacement
in the Periodic Maintenance chapter).
Unscrew the clamp bolts [B], and take off themaster cylinder
as an assembl ...