Parts for your 2022 Toyota C-hr-Radiator cap

2022 Toyota C‑HR radiator cap: where it is, what it does, and when to replace it

For the 2022 Toyota C‑HR, a radiator cap is absolutely relevant—it's fitted to the pressurised coolant reservoir (expansion tank) rather than on the radiator neck itself. Toyota’s service literature for C‑HR (model families ZYX10/NGX10/MXPA10) describes a “radiator cap sub‑assembly” mounted on the reservoir with a specified opening pressure, and the 2022 Owner’s Manual identifies and cautions against removing the coolant reservoir cap when hot. Toyota’s Electronic Parts Catalog also lists a radiator cap for C‑HR variants. Put simply: yes, the vehicle has a pressure cap, it’s just on the reservoir.

That cap’s job is to hold pressure in the cooling system so coolant can run hotter without boiling, and to manage coolant flow between the engine and the reservoir as things heat up and cool down. The pressure valve normally sits around 1.1 bar (roughly 108–137 kPa in Toyota specs), which bumps up the boiling point. A secondary vacuum valve lets coolant return to the engine during cool‑down so hoses don’t collapse and air isn’t sucked in.

As part of regular servicing, it’s smart to have the cap checked with a cooling‑system pressure tester and replaced if it doesn’t hold the rated pressure. A tired cap can cause sneaky problems like gradual coolant loss, random overheating at highway speeds, hard upper radiator hoses after a drive, or a collapsed hose once cold. Any white/pink crust around the neck or cap, a perished rubber seal, or coolant smell under the bonnet are also red flags.

Practical tips for C‑HR owners:

• Inspect the cap and reservoir at every service or at least every 30,000 km, consider replacing the cap around 5 years/100,000 km, or sooner if it fails a test.
• Always match the Toyota‑specified pressure rating and use genuine or quality equivalent. On hybrids, stick with Toyota Super Long Life Coolant (pink) and never mix colours.
• Only remove the cap when the engine is stone cold. Crack it slowly to release any residual pressure.
• If topping up, fill to the “F” mark on the reservoir. After any drain/refill, bleed the system per Toyota procedure to avoid air pockets.

Because the C‑HR’s cap sits on the reservoir, access is easy—no need to reach down to the radiator. Swapping it is a quick, low‑cost fix that can save a lot of grief from overheating or coolant loss.

Technical sources referenced: Toyota C‑HR Repair Manual (Cooling System—Cap inspection and specifications for ZYX10/NGX10/MXPA10), 2022 Toyota C‑HR Owner’s Manual (Engine compartment—coolant reservoir and cautions), and Toyota Electronic Parts Catalog listings for the radiator cap sub‑assembly used on C‑HR variants.

Where is the radiator cap on a 2022 Toyota C‑HR?

It’s on the pressurised coolant reservoir (expansion tank) under the bonnet, not on the radiator itself. Look for the black cap with warning text on the translucent tank—easy to spot and reach. Only open it when the engine is completely cold.

What pressure rating should the C‑HR radiator cap be?

Toyota specs for C‑HR call for a cap around 1.1 bar (approximately 108–137 kPa). Always match the rating printed on the original or follow Toyota service data for your exact engine variant to keep cooling performance spot‑on.

Is it safe to drive with a faulty radiator cap?

Not really. A weak cap can cause overheating, coolant loss, and air ingestion, which can snowball into bigger repairs. If there are signs of a dodgy cap—leaks, stains, collapsed hose after cool‑down—replace it and pressure‑test the system to be safe.