If any one of them shows visible damage, replace the cap with a new one.

NOTE
Wet the cap sealing surfaces with water or coolant to prevent pressure leaks.

Radiator Cap Relief Pressure Standard: 112 ∼ 142 kPa (1.14 ∼ 1.45 kgf/cm², 16 ∼ 21 psi)
If the cap can not hold the specified pressure or if it holds too much pressure, replace it with a new one.
Radiator Inspection
Radiator Filler Neck InspectionSelf-Diagnosis Outline
The self-diagnosis system is monitoring the following
mechanisms.
DFI System and Ignition System
S-KTRC System
Immobilizer System (Equipped Models)
KIBS and ABS (Equipped Models)
ESD (Electronic Steering Damper) System
(ZX1000JD/KD)
The following warning indicator lights (LED) are used for ...
Front Forks/Rear Shock Absorber Operation Inspection
Pump the forks down and up [A] 4 or 5 times, and inspect
the smooth stroke.
If the forks do not smoothly or noise is found, inspect the
fork oil level or fork clamps (see Front Fork Oil Change in
the Suspension chapter).
Pump the rear seat down and up [A] 4 or 5 times, and
inspec ...
Rear Shock Absorber Installation
Replace the rear shock absorber nuts and tie-rod nuts
with new ones.
Tighten:
Torque - Rear Shock Absorber Nuts: 34 N·m (3.5 kgf·m, 25
ft·lb)
Tie-Rod Nuts: 34 N·m (3.5 kgf·m, 25 ft·lb)
When installing the rear shock absorber bracket [A], install
it so that the recess side [B] ...