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Frequently asked questions about cars and motorcycles

How to Replace the Heater Seal on a Ford Focus MK3?

Model: Ford Focus MK 3 - Years 2011-2018
Part: Radiator

Let’s see how to replace the heater seal on a Ford Focus MK3: the video shows coolant leaking from the connection between the two metal collars that connect to the cabin radiator. This operation must be done with the engine cold; you need to relieve the system pressure by slowly opening the expansion tank cap (located near the windscreen on the passenger side) and collecting the fluid. The heater hoses enter the cabin through the bulkhead on the passenger side, so you will need to remove the air filter, move the windscreen washer reservoir, and you will see two metal hoses with screw-type clamps. Loosen the two clamp bolts and, with a slight twist, pull back the metal hoses to remove them from the cabin radiator, remove the old seals, clean the seats thoroughly, and fit the new seals, lubricated with clean coolant. Reconnect the hoses, top up the fluid, bleed the system, start the engine, and check for leaks.

Posted on 4 August 2026 by ScegliAuto

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