Hardening, shrinkage, or damage of both gaskets and O-rings after disassembly can reduce sealing performance.
Remove old gaskets and clean the sealing surfaces thoroughly so that no gasket material or other material remains.
Install the new gaskets and replace the used O-rings when re-assembling.

Force
Liquid Gasket, Non-permanent Locking AgentDrive Chain Lubrication Condition Inspection
If a special lubricant is not available, a heavy oil such as
SAE 90 is preferred to a lighter oil because it will stay on
the chain longer and provide better lubrication.
If the chain appears especially dirty, clean it before lubrication.
NOTICE
The O-rings between the side plates seal ...
Rear Fender Front Installation
Installation is the reverse of removal. Note the following.
Run the harness, cables and leads correctly (see Cable,
Wire, and Hose Routing section in the Appendix chapter).
When installing the clamp [A] on the rear fender front [B],
install it so that the clamp positions at near the ...
Brake Line Bleeding
The brake fluid has a very low compression coefficient so
that almost all the movement of the brake lever or pedal
is transmitted directly to the caliper for braking action. Air,
however, is easily compressed. When air enters the brake
lines, brake lever or pedal movement will be partially used
...