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 DamageBalance Weight Installation
Check if the weight portion has any play on the blade [A]
and clip [B].
If it does, discard it.
WARNINGUnbalanced wheels can create an unsafe
riding
condition. If the balance weight has any play on
the rib of the rim, the blade and/or clip have been
stretched. Replace th ...
Piston Ring Groove Width Inspection
Measure the piston ring groove width.
Use a vernier caliper at several points around the piston.
Piston Ring Groove Width
Standard:
Top [A] 0.82 0.84 mm (0.0323
0.0331 in.)
Second [B] 0.82 0.84 mm
(0.0323 0.0331 in.)
Service Limit:
0.92 mm (0.036 in.)
Second 0.92 mm (0.036 in.)
...
Diode Circuit Inspection
Remove the relay box (see Relay Box Removal).
Check conductivity of the following pairs of terminals (see
Relay Box Internal Circuit in this section).
Diode Circuit Inspection
The resistance should be low in one direction and more
than 10 times as much in the other direction. If any dio ...