2010 Polaris Sportsman 850 Service Manual, Page 34Get this manual
MAINTENANCE 9If coolant was required, start engine and check for leaksMake sure radiator fins are clean to prevent overheating
Coolant StrengthType
Test the strength of the coolant using an antifreeze hydrometer
10Add coolant as neededMaintain the coolant level between the "MIN" and "MAX" marks on the bottle11Reinstall the front rack assemblyAntifreeze Hydrometer