Parts for your 2015 Ford Falcon-Radiator cap

2015 Ford Falcon radiator cap — what’s actually on the car?

For the 2015 Ford Falcon (FG X), a traditional radiator neck with a screw-on radiator cap isn’t used. Instead, the cooling system is sealed and managed by a pressure cap fitted to the pressurised expansion/degas bottle. Ford’s FG/FG X Workshop Manual (Engine Cooling, 303-03) diagrams the surge tank and specifies the cap as the system’s pressure control point, the radiator itself has no filler neck. The 2015 Falcon Owner’s Manual also directs coolant checks and topping-up at the expansion tank cap, not the radiator. Local parts catalogues and service bulletins list this component as a “coolant reservoir/degas bottle cap”.

Why the change? Modern Falcons place the surge tank higher than the radiator, which helps separate air from coolant and makes bleeding simpler after service. With no cap on the radiator, there’s better packaging under the bonnet and fewer chances for someone to pop a hot radiator cap and get scalded. The pressurised tank cap governs system pressure and vacuum relief as the engine heats and cools, doing the exact job the old-school radiator cap used to do—just in a smarter spot.

If someone’s shopping for a “radiator cap” for a 2015 Falcon, what they actually need is the coolant reservoir/degas bottle cap. A few quick tips make ownership easy:

• Check the cap at every service. Look for brittle plastic, perished rubber seals, cracked tabs, or dried coolant staining around the neck.
• Use the pressure rating shown on the cap label (often around 140 kPa/20 psi). The wrong rating can cause leaks or overheating.
• If there’s unexplained coolant loss, a sweet smell, swollen hoses, or the system won’t hold pressure, have the cap pressure-tested and replace if it fails.
• Only remove the cap when the engine is cold. If you must open it warm, wrap with a rag and release slowly.
• Refill with the coolant type and mix specified in the owner’s manual and on the under-bonnet decals, avoid tap water—use demineralised water if not using pre-mix.

Bottom line: the 2015 Falcon absolutely uses a pressure cap—just not on the radiator. Treat the degas bottle cap as a critical service item to keep temps stable and the Falcon happy on Aussie and Kiwi roads.

Popular questions about the 2015 Ford Falcon “radiator cap”

Does a 2015 Ford Falcon have a radiator cap?
No. The radiator itself has no cap. The system uses a pressure cap on the expansion/degas bottle, which controls pressure and vacuum in the cooling system. That’s the part most people mean when they say “radiator cap” on this model.

What pressure cap does the 2015 Falcon use?
Commonly around 140 kPa (about 20 psi), but always check the printing on your existing cap and the owner’s manual. Using a cap with the wrong rating can lead to leaks, overheating, or hoses ballooning.

How often should the cap be replaced?
Inspect it at every service and pressure-test if there are cooling issues. Many techs proactively replace the cap every few years, or immediately if the seal is perished, it won’t hold pressure, or there’s evidence of venting around the neck.