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
RadiatorMaster Cylinder Inspection (Visual Inspection)
Remove the master cylinders (see Front/Rear Master
Cylinder Removal).
Disassemble the front and rear master cylinders (see
Master Cylinder Rubber Parts Replacement in the Periodic
Maintenance chapter).
Check that there are no scratches, rust or pitting on the
inner wall [A] of each ma ...
Oil Pump Drive Gear Installation
Install is the reverse of removal. Note the following.
First, engage the oil pump chain [A] to the gears, and then
install the oil pump drive gear [B].
Turn the “OUT” mark [C] to outside.
Apply a non-permanent locking agent to the oil pump drive
chain guide bolt and the oil pump drive ...
Piston Ring End Gap Inspection
Place the piston ring [A] inside the cylinder (upper
crankcase), using the piston to locate the ring squarely
in place. Set it close to the bottom of the cylinder, where
cylinder wear is low.
Measure the gap [B] between the ends of the ring with a
thickness gauge.
Piston Ring End Gap ...