This procedure covers the removal and replacement of the lower radiator hose on a 2021-2024 Ford F-150 with the 3.5L EcoBoost V6 engine, including coolant drainage and refill.

Warnings

Tools required

Parts

• Lower radiator hose × 1 — Use OEM specification
• Hose clamps (if reusing old clamps shows wear) × 2 — Use OEM specification

Fluids

• Motorcraft Orange Coolant — 13 qt

Preparation

1. Ensure the engine is completely cold before beginning work
2. Park the vehicle on a level surface and engage the parking brake
3. Place drain pan underneath the radiator drain petcock location
4. Remove the engine cover by pulling upward on the cover to disengage the retaining grommets

Procedure

1. 1

   Drain the cooling system
   Locate the radiator drain petcock at the bottom driver's side of the radiator. Slowly turn the petcock counterclockwise to open and allow coolant to drain into the pan. Once flow stops, close the petcock hand-tight.
   Torque spec

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

   Access the lower radiator hose
   From under the vehicle, locate the lower radiator hose connecting the bottom of the radiator to the engine block on the passenger side. The hose runs from the radiator outlet to the water pump inlet. Clear any debris or components blocking access to the hose clamps at both ends.
   ℹ️The lower hose may have additional coolant trapped inside. Keep the drain pan positioned to catch residual fluid.
3. 3

   Remove radiator-side hose clamp
   Using hose clamp pliers or a flathead screwdriver, loosen the clamp securing the lower hose to the radiator outlet. Slide the clamp away from the connection point along the hose at least 2-3 inches to provide clearance.
4. 4

   Remove engine-side hose clamp
   Locate and loosen the hose clamp at the water pump inlet connection. Slide this clamp away from the connection point along the hose.
5. 5

   Remove the lower radiator hose
   Twist the hose gently at both connection points to break the seal, then pull firmly to disconnect from the radiator outlet and water pump inlet. The hose may require significant force if it has been in place for an extended period. Allow any remaining coolant to drain into the pan.
   ⚠Inspect the radiator outlet and water pump inlet for corrosion, cracks, or damage. Address any damage before installing the new hose.
6. 6

   Prepare the new hose
   Clean the radiator outlet and water pump inlet thoroughly with shop towels. Remove any old gasket material or debris. Position the hose clamps onto the new lower radiator hose before installation, with one clamp near each end. Ensure clamps are positioned to be accessible once the hose is installed.
7. 7

   Install the new lower radiator hose
   Connect the new hose to the water pump inlet first, pushing firmly until it seats completely against the inlet stop. Then connect the other end to the radiator outlet, ensuring it is fully seated. Verify both connections are completely inserted and properly aligned.
8. 8

   Secure the hose clamps
   Slide the hose clamps into position over the connection points. Position each clamp approximately 1/4 inch from the end of each connection. Tighten both clamps to the specified torque using a torque wrench.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
9. 9

   Refill the cooling system
   Using a funnel, add Motorcraft Orange Coolant to the radiator and coolant reservoir. Fill the reservoir to the COLD FILL line. Start with approximately 10 quarts in the radiator, then start the engine and allow it to warm up to operating temperature with the radiator cap off. Add coolant as the level drops during the bleeding process.
   ⚠Run the engine with the heater set to maximum temperature to ensure coolant circulates through the entire system and air pockets are purged.
10. 10

    Bleed air from the system
    With the engine at operating temperature, allow it to idle for 10-15 minutes. Carefully squeeze the upper radiator hose several times to help release trapped air. Continue adding coolant as needed until the level stabilizes. Once no more air bubbles appear and the level is stable, install the radiator cap.
11. 11

    Final fill and inspection
    Top off the coolant reservoir to the COLD FILL line. Reinstall the engine cover by aligning the grommets and pressing down firmly. Clean up any spilled coolant from the engine bay and undercarriage.

Reassembly

1. Ensure all hose clamps are torqued to specification and positioned correctly over connection points
2. Verify the coolant reservoir is filled to the COLD FILL line
3. Confirm the radiator drain petcock is closed and torqued properly
4. Reinstall the engine cover securely

Verification

• Start the engine and allow it to reach operating temperature while monitoring for leaks at both hose connections
• Check for proper heater operation by verifying hot air flow from cabin vents
• Inspect the coolant level after the engine cools and top off if necessary to the COLD FILL line
• After the first drive cycle, recheck all connections for leaks and verify coolant level
• Monitor coolant level and temperature gauge for the next few days to ensure proper system operation

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