Kia Optima Hybrid Owner's Manual Quiz
Engine Mechanical System

Radiator Repair Procedures

In this manual: Engine Mechanical System
General Information — 4Engine Mechanical System — 50Engine Electrical System — 20Emission Control System — 30Engine Control System/Fuel System — 84Automatic Transmission — 98Drive Shaft and Axle — 15Suspension System — 36Steering — 12Restraints — 50Brake System — 38Body (Interior and Exterior) — 54Body Electrical System — 233Heating, Ventilation, and Air Conditioning — 57
24steps
~144min
4/5difficulty
010203040507.86N·mlb·ft
Tightening torque found on this page
Done 0 of 24

Inspection

Radiator Cap Inspection
  1. Remove the radiator cap, wet its seal with engine coolant, then install it on the pressure tester.
  2. Apply pressure of 93.16 ~ 122.58 kPa (0.95 ~ 1.25 kgf/cm², 13.51 ~ 17.78 psi).
  3. Check for pressure drop.
  4. If the pressure drops, replace the radiator cap.
  5. Wait until the engine has cooled, then carefully remove the radiator cap and fill the radiator with engine coolant, then install the radiator cap tester (A).
  6. Connect the tester to the radiator and apply pressure of 93.16~122.58 kPa (0.95~1.25 kgf/cm², 13.51~17.78 psi).
  7. Check for engine coolant leaks and pressure drop.
  8. Remove the tester and install the radiator cap.
    Check for engine oil in the coolant and/or coolant in the engine oil.
Radiator Leak Test

Removal and Installation

  1. Disconnect the negative battery terminal(s). (Refer to Engine and Transaxle Assembly in this group)
  2. Remove the air cleaner assembly. (Refer to Engine and Transaxle Assembly in this group)
  3. Disconnect the cooling fan motor connector (A).
  4. Remove the upper radiator hose clamp (B).
  5. Remove the electric water pump (EWP) inlet pipe mounting bolts (A).
  6. Remove the cooling fan assembly (A).

    Tightening Torque: 4.9 ~ 7.8 N·m

  7. Remove the under cover. (Refer to Engine and Transaxle Assembly in this group)
  8. Loosen the drain plug (A) and drain the engine coolant. Remove the radiator cap to drain the coolant faster.
  9. Disconnect the overflow hose (A) from the radiator.
  10. Disconnect the upper radiator hose (A) and lower hose (B).
  11. Remove the radiator mounting brackets (A).

    Tightening torque: 3.9 ~ 5.9 N·m

  12. Drain the inverter coolant, then disconnect the inverter radiator hoses. (Refer to Group BT - "Coolant")
  13. Separate the condenser from the radiator and remove the radiator assembly (A).
  14. Remove the inverter radiator (A) from the radiator assembly (B). (Refer to Group HT - "Radiator")
  15. Installation is the reverse of removal.
  16. Fill the radiator with coolant and check for leaks.
    • Bleed air from the hybrid engine cooling system before the engine cooling system. (Refer to Group HT - "Coolant")
    • Bleed air from the engine cooling system.
    • Start the engine and let it run until it warms up (until the radiator fan has cycled 3 or 4 times).
    • Turn off the engine. Check the coolant level and add coolant if necessary. This will remove trapped air from the cooling system.
    • Tightly close the radiator cap, then restart the engine and check for leaks.

Test yourself

A quick Kia Optima Hybrid Owner's Manual quiz: every answer comes with an explanation and a link to the manual page.