Parts for your 2022 Mitsubishi Asx-Radiator cap

2022 Mitsubishi ASX radiator-cap: what it does and how to look after it

Technical sources confirm the 2022 Mitsubishi ASX is fitted with a pressurised radiator-cap. The Mitsubishi Motors Service Manual for ASX/RVR/Outlander Sport (GA/GA2W series, Group 14—Cooling) specifies a pressure radiator-cap and outlines inspection and testing procedures. The 2022 ASX Owner’s Manual also cautions against opening the radiator-cap when hot, and Mitsubishi’s electronic parts catalog (ASA/EPC) lists a genuine “Cap, Radiator” for ASX petrol variants, typically around 108 kPa (about 1.1 bar), with part numbers varying by market.

The radiator-cap on a 2022 Mitsubishi ASX does more than just seal the top of the radiator. It’s a pressure regulator for the cooling system, letting the engine run at a higher boiling point so coolant won’t start steaming when you’re stuck in traffic on a scorching Aussie or Kiwi afternoon. Inside the cap are pressure and vacuum valves that allow excess pressure to vent to the overflow bottle and draw coolant back in as the engine cools. That keeps air out, stabilises temperatures, and protects hoses and the radiator from stress.

As part of routine servicing, the radiator-cap deserves a quick check under the bonnet when the engine is completely cold. Look for perished rubber seals, a weak or sticky spring, corrosion on the seat, or a cracked/warped neck. A workshop can pressure-test the cap to verify it holds the specified rating for your ASX. If the cap can’t hold pressure—or releases too early—it’s time to replace it.

When replacing, match the correct pressure rating for your 2022 ASX and stick with genuine or quality aftermarket. Don’t open the cap when hot, wait until the system is cool. After fitting a new cap, confirm the overflow hose is snug and the coolant in the reservoir is at the “COLD” mark. If the cooling system has been opened for other work, bleed it properly so no air pockets remain.

Common clues the radiator-cap is on the way out include unexplained coolant loss, the overflow bottle repeatedly overfilling or staying empty, temperature swings, soft hoses collapsing as the engine cools, or heater performance dropping off. There’s no hard interval for cap replacement, but checking it at every service and renewing it during major cooling-system work (for example at 5–7 years or high kilometres) is cheap insurance for an ASX that has to handle summer heat, long open-road runs, and the odd towing job.

• Never open the radiator-cap when hot—risk of burns and system damage.
• Use the specified pressure rating for your ASX variant (commonly around 108 kPa).
• Inspect the overflow hose and bottle level whenever you check the cap.

Popular questions

What pressure radiator-cap does a 2022 Mitsubishi ASX use?

Most 2022 ASX petrol models use a cap around 108 kPa (about 1.1 bar), but the exact rating can vary by engine and market. Always check the marking on your existing cap or consult the vehicle information label and service data to match it correctly.

How often should the radiator-cap be replaced on a 2022 ASX?

There’s no fixed kilometre interval. Have it inspected at every service and pressure-tested if there are any cooling concerns. Many owners choose to replace the cap proactively during a coolant change or around the 5–7 year mark to avoid nuisance overheating and coolant loss.

What are the signs of a failing radiator-cap on an ASX?

Watch for coolant pushing into the overflow bottle and not returning, a sweet smell after stopping, hoses collapsing as the engine cools, fluctuating temperature readings, or dried coolant residue around the neck. Any of these are a cue to test the cap and the system.