Honda 2012 TRX420TM Owner's Manual page 128

Coolant
Increasing the concentration of antifreeze is not recommended because
it decreases cooling system performance. Higher concentrations of
antifreeze (up to 60%) should only be used to provide additional
protection against freezing. Check the cooling system frequently during
freezing weather.
Checking & Adding Coolant
Refer to Saf ety Precautions
Check the engine coolant level each day before operating your ATV and
add if needed.
RIGHT REAR
(1)
(2)
(3)
(1) reserve tank
(2) UPPER level mark
1. Make sure the vehicle is on level ground.
2. With the engine at normal operating temperature, check the coolant
level in the reserve tank ( ). It should be between the UPPER ( )
and LOWER ( ) level marks. 3
If the reserve tank is empty, or if coolant loss is excessive, check for
leaks and see your dealer for repair.
120 Servicing Your Honda
on page 89 .
(3) LOWER level mark
1 2