Honda FourTrax Foreman Rubicon 2005 Service Manual page 146

COOLING SYSTEM
SYSTEM TESTING
6-4
Remove the screw and radiator cap lid from the ' S- C R - E - W - - - - -
front fender.
Remove the radiator cap.
COOLANT (HYDROMETER TEST)
Test the coolant gravity usi ng a hydrometer.
STAN DARD COOLANT CONCENTRATION: 1:1
look fo r contamination and replace the coolant
if
necessary.
RADIATOR CAP
RADIATOR
CAP LID