Complete drain and refill of the engine cooling system with fresh Mopar OAT coolant, including air bleeding to ensure proper operation and prevent overheating.

Warnings

Tools required

Parts

• Radiator drain plug washer × 1 — Mopar 68080603AA or equivalent
• Coolant system hose clamps (if corroded) × 1 — As needed based on condition

Fluids

• Mopar OAT Coolant (Purple) — 18 qt

Preparation

1. Ensure engine is completely cold before beginning work
2. Park vehicle on level surface and engage parking brake
3. Place wheel chocks behind rear wheels
4. Gather all tools, drain pan, and fresh coolant before starting
5. Verify you have correct Mopar OAT purple coolant (do not substitute)
6. Open hood and secure in raised position

Procedure

1. 1

   Remove radiator cap and access lower drain
   Slowly rotate the radiator cap counterclockwise to the first detent and allow any residual pressure to release. Once pressure is relieved, press down and continue rotating to remove the cap completely. Locate the radiator drain plug on the lower driver side of the radiator. Place the drain pan underneath with sufficient capacity for at least 18 quarts of coolant.
2. 2

   Drain cooling system from radiator
   Using a socket, carefully loosen and remove the radiator drain plug at the bottom of the radiator. Allow coolant to drain completely into the drain pan. This will take several minutes. Inspect the drain plug washer for damage or deterioration and replace if necessary.
3. 3

   Drain engine block if equipped with drain petcock
   If your engine block has an accessible drain petcock (typically on the driver side of the block), open it to drain residual coolant from the engine block. Some model configurations may not have this feature. Allow complete drainage before proceeding.
4. 4

   Inspect cooling system components
   While the system is drained, visually inspect all accessible coolant hoses for cracks, bulges, or soft spots. Check hose clamps for corrosion. Inspect the radiator for leaks or damage. Replace any questionable components now before refilling the system.
5. 5

   Reinstall drain plug and petcock
   Install a new drain plug washer if the old one is damaged. Thread the radiator drain plug into the radiator by hand to ensure proper thread engagement, then torque to specification. If a block drain petcock was opened, close it hand tight to specification.
   Torque spec

   Drain Plug15 Nm (11 lb-ft)

   Drain Petcock5 Nm (4 lb-ft)
6. 6

   Locate and open cooling system bleed screw
   Locate the cooling system air bleed screw on top of the thermostat housing or on the upper coolant crossover tube. Using a wrench, loosen the bleed screw approximately 2-3 turns. Leave it open during the fill process to allow air to escape from the system.
   Torque spec

   Bleed Screw7 Nm (5 lb-ft)
7. 7

   Begin coolant fill procedure
   Using a funnel in the radiator fill neck, slowly pour fresh Mopar OAT purple coolant into the system. Fill slowly to allow air to escape through the open bleed screw. The system capacity is 18 quarts, but you may not be able to add the full amount initially due to air pockets. Watch for coolant to begin flowing from the bleed screw opening.
8. 8

   Close bleed screw when coolant appears
   Once a steady stream of coolant (without air bubbles) flows from the bleed screw, close the screw by torquing to specification. Continue filling the radiator to the top of the fill neck. Install the radiator cap but leave it loose (do not fully tighten yet).
   Torque spec

   Bleed Screw7 Nm (5 lb-ft)
9. 9

   Initial engine warm-up cycle
   Start the engine and allow it to idle. Monitor the temperature gauge closely. As the engine warms, the thermostat will open and coolant level may drop in the radiator. Keep the radiator cap loose to allow air to escape. Watch for coolant circulation in the radiator when looking down the fill neck.
   ⚠Monitor engine temperature closely during this process. If temperature exceeds normal operating range, shut off engine immediately and investigate for air pockets or system problems.
10. 10

    Add coolant and complete air purge
    With the engine at idle and warmed to operating temperature (thermostat open), add additional coolant to the radiator as the level drops. Run engine for 10-15 minutes total, allowing the cooling fan to cycle on at least once. Add coolant as needed to maintain proper level. You may need to briefly open and close the bleed screw again if air pockets persist.
11. 11

    Shut down and final fill
    Shut off the engine and allow it to cool for 15-20 minutes. The coolant level should drop slightly as the system cools. Top off the radiator to the fill neck and verify the coolant recovery tank is filled to the HOT mark. Securely install the radiator cap.
12. 12

    Verify system integrity and check for leaks
    Inspect all drain points, hose connections, and the area around the bleed screw for any signs of coolant leakage. Clean any spilled coolant from engine surfaces. Wipe down the radiator drain plug area to verify no seepage.

Reassembly

1. Ensure radiator cap is fully tightened and properly seated
2. Verify coolant recovery tank is filled to HOT mark
3. Clean any coolant residue from engine bay surfaces
4. Dispose of old coolant properly at a recycling center or auto parts store

Verification

• Start engine and verify it reaches normal operating temperature without overheating
• Confirm cooling fan cycles on and off properly
• Check that heater produces hot air when controls are set to heat
• After 24 hours of driving, recheck coolant level when engine is cold and top off if necessary
• Verify no coolant leaks at drain plug, hose connections, or bleed screw
• Monitor temperature gauge during first few driving cycles to ensure proper cooling system operation

More procedures for this vehicle