If any one of the parts is damaged, replace the mechanical seal as a unit.
Rubber Seal [A] Mechanical Seal [B]

Water Pump Housing Assembly
RadiatorSeparator Operation Test
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions. Turn the ignition
switch OFF. Do not smoke. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light.
...
Piston Wear Inspection
Measure the outside diameter [A] of each piston 5 mm
(0.20 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is under service limit, replace the piston.
Piston Diameter
Standard: 75.959 75.974 mm
(2.9905 2.9911 in.)
...
Brake Fluid Leak (Brake Hose and Pipe) Inspection
For KIBS equipped models, remove the fuel tank (see
Fuel Tank Removal in the Fuel System (DFI) chapter).
Apply the brake lever or pedal and inspect the brake fluid
leak from the brake hoses [A], pipes (KIBS equipped models)
[B] and fittings [C].
If the brake fluid leaked from any posit ...