The fluid seal (piston seal) [A] is placed around the piston to maintain clearance between the pad and the disc. If the seal is in a poor condition, it could lead the pad to wear excessively or the brake to drag, which may cause the temperature of the discs or the brake fluid to increase.

Brake fluid leakage around the pad.
Brakes overheat.
Considerable difference in inner and outer pad wear.
Seal and piston are stuck together.
If the fluid seal is replaced, replace the dust seal [B] as well. Also, replace all seals every other time the pads are changed.
Front Caliper [C] Rear Caliper [D]

Caliper Installation
Rear Caliper Dust Boot and Friction Boot DamageDFI Servicing Precautions
There are a number of important precautions that should
be followed servicing the DFI system.
This DFI system is designed to be used with a 12 V sealed
battery as its power source. Do not use any other battery
except for a 12 V sealed battery as a power source.
Do not reverse the battery ...
Ignition Switch Replacement
Remove:
Air Cleaner Housing (see Air Cleaner Housing Removal
in the Fuel System (DFI) chapter)
Disconnect the lead connectors [A].
Remove:
Steering Stem Head (see Stem, Stem Bearing Removal
in the Steering chapter)
Using a small chisel or punch [A], turn out the Torx bolts.
...
Camshaft, Camshaft Cap Wear Inspection
Remove the camshaft caps (see Camshaft Removal).
Cut the strips of plastigage (press gauge) to journal width.
Place a strip on each journal parallel to the camshaft installed
in the correct position.
Tighten the camshaft cap bolts and upper camshaft chain
guide bolts to the specified ...