Parts for your 2025 Mitsubishi Eclipse cross-Radiator cap

2025 Mitsubishi Eclipse Cross radiator cap — what’s actually fitted

Short answer: there isn’t a traditional radiator cap on the 2025 Mitsubishi Eclipse Cross. Mitsubishi’s owner’s manual and workshop service information for the Eclipse Cross (GK series carried into MY25) show a sealed cooling system that’s filled and pressure-controlled at a pressurised coolant reservoir (also called a surge or degas tank). Factory parts catalogues list a pressure cap for the reservoir and no separate cap on the radiator itself. That means a “radiator cap” as found on older radiators isn’t used on this model.

Why the change? Modern cooling systems are designed around a high-mounted, pressurised reservoir. This layout improves air separation and self-bleeding, keeps the hottest coolant routed past the pressure cap for reliable pressure control, and removes the need for a filler neck on the radiator. It also helps packaging under the bonnet and reduces potential leak points on today’s plastic/aluminium radiators.

So, while people still say “radiator cap”, on the 2025 Eclipse Cross the relevant part is the engine coolant reservoir cap. It works the same way a traditional radiator cap would: maintaining system pressure so coolant boils at a higher temperature and venting to the overflow path if pressure spikes. If there are overheating, loss-of-coolant, or boiling concerns, the reservoir cap is one of the first items to inspect or pressure-test.

• Only open the coolant reservoir cap when the engine is completely cold. The cap is “Do not open when hot” for good reason.
• Check the cap’s rubber seal for nicks, flattening, or cracking, and make sure the spring feels firm. A tired cap can cause slow coolant loss and higher running temps.
• Top up to the “FULL” or “MAX” mark with the coolant type and mix specified in the owner’s manual for your market. Mixing incompatible coolants can cause sludge or corrosion.
• If the cooling system has been opened for repairs, follow the workshop bleeding procedure or have a technician bleed it to avoid trapped air.

If the cap’s label shows damage, the seal looks perished, or a pressure test fails, replace the reservoir cap. They’re inexpensive and can save headaches with overheating or coolant odours under the bonnet.

Popular questions

Does the 2025 Eclipse Cross have a radiator cap?
No. The radiator itself is sealed. The pressure cap is on the engine coolant reservoir (surge tank), which handles filling, pressure control, and venting.

Where is the coolant cap and what pressure should it be?
The cap sits on the translucent coolant reservoir bottle in the engine bay. The pressure rating is printed on the cap face, check the cap and the owner’s manual for the exact spec for your vehicle.

How do they top up coolant on a 2025 Eclipse Cross?
Only when the engine is cold, remove the reservoir cap and fill to the “FULL/MAX” mark with the specified coolant. If the system was opened for repairs, it may need a proper bleed procedure to clear air—best done with workshop equipment.