Honda TRX450ER Owner's Manual page 115

Coolant
3. Remove the steering cover ( ) and reserve tank cap ( ).
Always add coolant to the reserve tank. Do not attempt to add coolant
by removing the radiator cap.
4. Add coolant to the reserve tank as required to bring the coolant level
to the UPPER level mark.
FRONT
(4)
(4) steering cover
5. After adding coolant, install the reserve tank cap and steering cover.
106 Servicing Your Honda
4
(5) reserve tank cap
5
(5)