This procedure covers replacement of both the upper and lower radiator hoses on the 2012-2018 Jeep Wrangler JK with the 3.6L Pentastar V6 engine.

Warnings

Tools required

Parts

• Upper radiator hose × 1 — Mopar 68102346AB or equivalent
• Lower radiator hose × 1 — Mopar 68102345AB or equivalent
• Hose clamps (if reusing factory clamps is not desired) × 4 — Use OEM specification

Fluids

• Mopar OAT Coolant (Purple) — 13 qt

Preparation

1. Ensure the engine is completely cold before beginning work
2. Park the vehicle on level ground and engage the parking brake
3. Place drain pan beneath the radiator drain petcock location on the passenger side lower corner of the radiator
4. Remove the radiator cap slowly to release any residual pressure

Procedure

1. 1

   Drain the cooling system
   Locate the radiator drain petcock on the passenger side lower corner of the radiator. Open the petcock by turning counterclockwise and allow coolant to drain into the drain pan. Once drained, close the petcock hand-tight.
   Torque spec

   Drain Petcock8 Nm (6 lb-ft)
2. 2

   Access the upper radiator hose
   The upper radiator hose connects the radiator upper tank to the thermostat housing on the front of the engine. Locate the hose clamps at both the radiator and engine ends of the upper hose.
3. 3

   Remove upper hose clamps
   Using hose clamp pliers or a flat blade screwdriver, loosen both hose clamps on the upper radiator hose. Slide the clamps away from the connection points along the hose to provide clearance for hose removal.
   ℹ️Factory clamps are typically spring-type constant tension clamps. If replacing with worm-gear clamps, do not overtighten during reinstallation.
4. 4

   Remove the upper radiator hose
   Twist the upper hose back and forth while pulling to break it free from the radiator neck and thermostat housing. If the hose is stuck, carefully use a utility knife to cut along the seam where the hose meets the fitting, being careful not to damage the metal fittings. Remove the hose completely.
5. 5

   Access the lower radiator hose
   The lower radiator hose connects the radiator lower tank to the water pump inlet on the passenger side of the engine. Access is easier from underneath the vehicle. Locate the hose clamps at both ends of the lower hose.
6. 6

   Remove lower hose clamps
   Loosen both hose clamps on the lower radiator hose using hose clamp pliers or a flat blade screwdriver. Slide the clamps away from the connection points.
7. 7

   Remove the lower radiator hose
   Twist and pull the lower hose to remove it from the radiator and water pump connections. Use the same techniques as with the upper hose if it is stuck. Allow any remaining coolant to drain into the pan.
8. 8

   Clean the connection surfaces
   Clean the radiator neck fittings, thermostat housing outlet, and water pump inlet with a shop towel. Remove any old rubber residue, corrosion, or debris. Inspect the fittings for damage or deep corrosion that could cause leaks.
9. 9

   Install the new lower radiator hose
   Position the new lower radiator hose onto the water pump inlet first, ensuring it is fully seated. Route the hose to the radiator lower tank and push it fully onto the radiator fitting. Both ends should be pushed on until they bottom out against the fitting stops.
10. 10

    Secure the lower hose clamps
    Slide the hose clamps into position approximately 1/4 inch from the end of each hose. Tighten the clamps to the specified torque. Ensure the clamps are positioned over the bead on each fitting.
    ⚠Do not overtighten hose clamps as this can cut into the hose material and cause premature failure. Use a torque wrench for proper tightening.
    Torque spec

    Hose Clamps4 Nm (3 lb-ft)
11. 11

    Install the new upper radiator hose
    Position the new upper radiator hose onto the thermostat housing first, ensuring it is fully seated. Route the hose to the radiator upper tank and push it fully onto the radiator fitting until both ends bottom out.
12. 12

    Secure the upper hose clamps
    Slide the hose clamps into position approximately 1/4 inch from the end of each hose. Tighten the clamps to the specified torque. Verify both clamps are positioned over the beads on the fittings.
    Torque spec

    Hose Clamps4 Nm (3 lb-ft)
13. 13

    Refill the cooling system
    Using a funnel, slowly pour Mopar OAT purple coolant into the radiator until it reaches the bottom of the filler neck. Also fill the coolant recovery reservoir to the COLD MAX line. Allow time for air bubbles to escape during filling.
14. 14

    Bleed air from the cooling system
    Start the engine and allow it to idle with the radiator cap off. Run the engine until the thermostat opens and coolant begins to circulate (typically around 195°F). Add coolant as the level drops. Run the heater on high to help purge air. Once the cooling fan cycles on and off, turn off the engine and top off the radiator to the filler neck.

Reassembly

1. Install the radiator cap once the system is filled and bled
2. Verify the coolant recovery reservoir is at the proper COLD MAX level
3. Wipe down all connections and surrounding areas to make leak detection easier during verification

Verification

• Check for coolant leaks at all four hose clamp locations while the engine is running and at operating temperature
• Verify the cooling system maintains proper pressure and the upper radiator hose becomes hot to the touch, indicating proper thermostat operation
• After the first drive cycle, recheck coolant level when cold and top off the recovery reservoir if needed
• Inspect all hose connections after 50-100 miles of driving and retorque clamps if necessary

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