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 AgentTachometer
The tachometer shows the engine
speed in revolutions per minute (r/min,
rpm).
On the right side of the tachometer
face is a portion called the “red zone�.
Engine r/min (rpm) in the red zone is
above maximum recommended engine
speed and is also above the range for
good performance.
...
Radiator Hose and Pipe Inspection (coolant leak, damage, installation
condition)
The high pressure inside the radiator hose can cause
coolant to leak [A] or the hose to burst if the line is not
properly maintained.
Visually inspect the hoses for signs of deterioration.
Squeeze the hoses. A hose should not be hard and
brittle, nor should it be soft or swollen.
Repl ...
Vehicle-down Sensor Output Voltage Inspection
Remove the vehicle-down sensor.
Connect the measuring adapter [A] to the vehicle-down
sensor connectors as shown in the figure.
Special Tool - Measuring Adapter: 57001-1700
Main Harness [B]
Vehicle-down Sensor [C]
Connect a digital meter [D] to the measuring adapter
leads.
V ...