Parts for your 2018 Volvo Xc60-Radiator cap

2018 Volvo XC60 radiator cap: what it is, where it is, and whether it’s even a thing

For the 2018 Volvo XC60, a traditional radiator cap on the radiator itself isn’t used. Instead, this model runs a sealed, pressurised cooling system with a remote expansion (degas) tank, and the only cap in play is the pressure cap on that reservoir. Technical references back this up: the Volvo XC60 Owner’s Manual (2018) describes topping up coolant via the expansion tank and warns about opening the pressurised reservoir cap carefully, while Volvo’s VIDA workshop information specifies filling and bleeding through the expansion tank, not the radiator. Major parts catalogues likewise list a “coolant expansion tank cap” for this model and no separate “radiator cap”.

Why no old-school radiator cap? Volvo’s SPA-platform cooling layout uses a remote degas bottle to improve coolant deaeration, packaging, and serviceability. The radiator is a plastic–alloy unit without a filler neck, which helps reduce leak points and allows the front crash structure and airflow package (including intercoolers and condensers) to be tighter under the bonnet.

• Safety and service: The pressurised cap is placed high and accessible on the expansion tank, reducing the chance of scalding and keeping hands away from hot fans and narrow spaces at the radiator support.
• Better cooling control: Continuous deaeration via the degas bottle helps purge air, improving thermal stability—handy for turbocharged engines common in the XC60 range.
• Fewer leak paths: Eliminating a radiator-mounted cap and filler neck means fewer seals and joints to fail over time.

For owners searching “radiator cap” for this XC60, the part to look for is the coolant expansion tank cap. During routine servicing, it’s smart to inspect the cap’s seal for cracks or flattening, make sure the cap turns smoothly and locks positively, and check for any dried coolant residue around the tank neck—signs the cap may not be holding pressure. Only remove the cap when the engine is completely cool, and replace with the correct specification pressure rating as printed on the cap or specified in Volvo service information. A cap that can’t hold pressure can cause boil-over, heater performance issues, and higher engine temps. Use the approved Volvo coolant and fill at the expansion tank, then bleed per VIDA procedures if the system has been opened.

Popular questions about the 2018 Volvo XC60 radiator cap

Does a 2018 Volvo XC60 actually have a radiator cap?
Technically, no. It doesn’t have a cap on the radiator itself. It uses a pressurised cap on the coolant expansion tank, which serves the same pressure-control role.

Where does coolant get topped up on a 2018 XC60?
Coolant is added at the expansion (degas) tank only. Never try to open anything on the radiator—there’s no service cap there.

How often should the expansion tank cap be replaced?
There’s no fixed interval. Have it checked at every service. Replace it if the seal’s perished, it’s weeping, or if cooling-system pressure tests suggest the cap isn’t holding the specified pressure.