Difficulty Level: Intermediate

Estimated Time: 45–75 minutes (DIY) | 20–30 minutes (technician)

Tools Required: Basic socket set, screwdrivers, hose clamp tool (or pliers), coolant catch pan, jack and jack stands (if underbody access needed)

Steps

1. Safety First: Engine must be completely cold. Disconnect the negative battery terminal. Allow the engine bay to cool for at least 30 minutes if the vehicle was recently run.
2. Drain Coolant: Position a drain pan beneath the radiator petcock (lower right side of radiator). Open the petcock valve and allow coolant to drain fully. Dispose of used coolant responsibly.
3. Locate the Heater Hose: The water heater hose connects the engine water pump or thermostat housing to the heater core inlet. It runs along the driver's side firewall or beneath the intake manifold depending on your engine variant. Reference your fitment guide for exact routing.
4. Remove Hose Clamps: Using a hose clamp tool or adjustable pliers, carefully loosen and remove the hose clamps at both ends. Mark clamp positions with tape if they're to be reused.
5. Disconnect the Old Hose: Gently wiggle and twist the old hose to break the connection seal. Some coolant may remain—have your drain pan ready. Do not force—take time to avoid damaging connector ports.
6. Inspect Connection Points: Examine the heater core inlet and water pump outlet. Remove any debris or corrosion with a soft cloth. Dried coolant deposits can be gently cleaned with distilled water.
7. Install the New Hose: Position the replacement hose and ensure it routes cleanly without kinks or contact with moving parts (serpentine belt, alternator, etc.). Push connections firmly onto their ports until you feel a solid seating click.
8. Reinstall Hose Clamps: Slide clamps over each connection point and tighten in a cross pattern (don't over-tighten; hand-tight plus a quarter turn is sufficient). Excessive clamp torque can crush the hose and create future leaks.
9. Refill Coolant: Close the radiator petcock. Fill the radiator and expansion tank with fresh OE-specification coolant (Land Rover coolant concentrate mixed to proper ratio, typically 50:50 with distilled water). Do not use tap water—mineral content causes scaling.
10. Bleed Air: Start the engine and allow it to idle until the thermostat opens and coolant circulates. Carefully open the radiator cap and top up if needed. Rev gently to 2000 rpm for 30 seconds, then let the engine settle. Check the level again and top up as necessary.
11. Check for Leaks: Allow the engine to run at normal operating temperature for 10 minutes. Inspect both hose connections under the engine bay for any seepage. If a leak appears, immediately shut down and inspect the clamp and connection.
12. Reconnect Battery & Test: Reconnect the negative battery terminal. Drive the vehicle for 15 minutes at gentle speed to verify cabin heater function, coolant temperature stability, and the absence of warning lights on the dash.