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

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyFront Wheel Rotation Sensor Wiring Inspection (Service Code b 43)
Disconnect the front wheel rotation sensor lead connector
[A] (see Front Wheel Rotation Sensor Removal in the
Brakes chapter).
Disconnect the KIBS hydraulic unit lead connector (see
KIBS Hydraulic Unit Removal in the Brakes chapter).
Check the wiring continuity of the W lead and ...
Coupling Bearing Installation
Replace the bearing with a new one.
Press in the bearing [A] until it is bottomed.
Special Tool - Bearing Driver Set [B]: 57001-1129
Pack the bearing with high-temperature grease.
Replace the circlip with a new one.
Special Tool - Inside Circlip Pliers: 57001-143
Replace the grease se ...
Oil Seal, Grease Seal
Do not remove pressed oil or grease seals unless removal
is necessary. Replace with new ones whenever removed.
Press new oil seals with manufacture and size marks facing
out. Make sure the seal is aligned properly when installing.
Apply specified grease to the lip of seal before installing ...