How to Bleed the Cooling System in a 4.6 Range Rover

Vehicle engines generate enough heat to self-destruct, therefore, a proper functioning cooling system is crucial to help your engine dissipate that heat. The radiator is the most important component in your Range Rover's cooling system and must be maintained by you checking the antifreeze-water mixture level in the coolant tank. Pockets of air may be trapped in the cooling system, large enough to block a coolant passage hose. The creation of bubbles may also happen when you add more of the antifreeze-water mixture to the system. Once a year, a cooling system bleed is necessary on the Range Rover to get bubbles, along with rust and impurities, out of the cooling system.

Wear gloves and safety glasses. Remove the bleed hose from the valve on the inlet manifold. To check that the valve pin is not stuck, attach a suitable diameter tube to the valve opening and blow air through it, using your mouth. When done, discard the tube and replace the bleed hose. Check that all other cooling system hose connections are tight.

Remove the radiator filler cap to prevent pressure build-up. Take off the bleed screw and washer from the coolant rail. Loosen the heater hose bleed screw by two complete turns. Start your engine and let it run at idle speed.

Prepare a 50/50 ratio of antifreeze and water mixture in a plastic container. Pour the antifreeze-water mixture into the radiator's filler neck, filling it up to the rim.

Remove the coolant reservoir cap and add the same mixture in the above step into your coolant reservoir to the "Max" level. Recap the coolant reservoir. With the radiator filler cap off, your engine running and adding antifreeze-water mixture to the cooling system forces any bubbles out and disappears naturally into the atmosphere. You may even see bubbles coming out from the radiator filler neck.

Observe the coolant level in your coolant reservoir. The antifreeze-water mixture should be lower when the air pockets are forced out of the system. Check your temperature gauge on the Range Rover's instrument cluster. The temperature should be near or at the "Normal" level.

Add more antifreeze-water mixture into the radiator and the coolant reservoir. More bubbles are present in the system if the coolant level in the coolant reservoir continues to drop. Continue adding the antifreeze and water mixture to the system until the level stays on the "Max" line.

Replace the washer and tighten the bleed screw to coolant rail to 9 Nm with a torque wrench. Tighten the heater hose bleed screw by hand. Refit the radiator filler cap. Wipe clean around these areas with a clean cloth where fluid may ooze during the "radiator bleed."

Allow the engine to run for additional 10 minutes then turn it off. Let the engine cool. Check for cooling system leaks while the engine is cooling. Pay attention to the cooling system's hoses, caps and screws where leakage often occurs.

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