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
RadiatorStem, Stem Bearing Installation
Replace the bearing outer races with new ones.
Drive them into the head pipe at the same time.
Special Tools - Head Pipe Outer Race Press Shaft [A]:
57001-1075
Head Pipe Outer Race Driver,
55 [B]: 57001
-1446 or Bearing Driver Set: 57001-1129
Apply grease to the outer races.
...
Front, Rear Wheel Rotation Difference Abnormal Inspection (Service Code b
25)
Check the following and correct the faulty part.
Incorrect Tire Pressure
Tires not recommended for the motorcycle were installed
(incorrect tire size).
Deformation of Wheel or Tire
Missing Teeth or Clogging with Foreign Matter of Sensor
Rotor (see Wheel Rotation Sensor Rotor Inspe ...
Cylinder Head Cover Installation
Replace the cylinder head cover gasket [A] with a new
one
Using a high flash-point solvent, clean off any oil or dirt
that may be on the silicone sealant coating area. Dry
them with a clean cloth.
Apply silicone sealant [B] to the cylinder head as shown
in the figure.
Sealant - Li ...