2012 Sportsman 400/500 and EFI Tractor Service Manual 9923412, Page 30Get this manual
MAINTENANCE ADC SYSTEM (IF EQUIPPED)
ADC System Fluid Reservoir Location
The Active Descent Control reservoir is located by the radiator fill cap under the storage box access panelCheck the level and verify it is between the MAX and MIN lines, Add only Polaris ADC fluid when requiredNOTE: If empty reservoir is encountered, filling of fluid is still possibleVerify air is not trapped before proceeding with step 78Continue steps 6-8 on both sides in sequence until clean fluid is seen when bleeding occurs9Re-torque both bleeder valves to specification and reinstall cover caps