Parts for your 2014 Mitsubishi Asx-Radiator cap

2014 Mitsubishi ASX radiator cap: what it does and how to look after it

Technical sources confirm the 2014 Mitsubishi ASX is fitted with a radiator pressure cap. The Mitsubishi Motors Service Manual for ASX/RVR/Outlander Sport (Cooling System, 2013–2015) specifies a pressure cap on the radiator neck, and the Mitsubishi ASA parts catalogue lists “CAP, RADIATOR” (commonly 1.1 bar) for 4B11/4N1 engines. Australian application guides from well-known aftermarket suppliers also specify a 1.1 bar radiator cap for ASX models from 2010–2016. So yes—this vehicle uses a proper radiator cap rather than a cap only on a sealed expansion tank.

The radiator cap on a 2014 ASX does more than just seal the filler neck. It holds the cooling system at a set pressure to raise the boiling point of the coolant, helping the engine run at the right temperature under Aussie and Kiwi conditions. It also contains a vacuum valve to pull coolant back from the overflow bottle as the engine cools, keeping the system full and free of air pockets. A healthy cap protects against overheating, coolant loss, and nuisance leaks around hoses and the water pump.

• Routine checks: At each service, only when the engine is stone cold, remove the cap and inspect the rubber seals for nicks, flattening, or hardening. Make sure the spring-loaded centre valve moves smoothly.
• When to replace: If there’s unexplained coolant loss, crusty deposits around the cap or neck, overheating in traffic, a collapsed top hose after cool-down, or bubbling into the overflow bottle, the cap is a prime suspect. Many workshops treat the cap as a 3–5 year / 60,000–100,000 km item.
• Correct spec: Use the correct pressure rating (typically 1.1 bar/108 kPa for ASX). The wrong rating can cause early boil-over or stress the system.

Replacement is straightforward: with the bonnet up and the engine fully cool, press down and twist the old cap off, wipe the neck clean, check for neck damage, and fit the new cap firmly. Top up the radiator with the correct coolant mix, bleed air per the service procedure, and set the overflow bottle to the “FULL” mark. Choosing a quality OEM-equivalent cap is cheap insurance for the ASX’s alloy engine and modern cooling system.

Does the 2014 Mitsubishi ASX have a radiator cap or just a reservoir cap?
The 2014 ASX has a pressure cap on the radiator neck and a separate overflow bottle. It’s not a sealed, reservoir-only setup.

What pressure rating does the ASX radiator cap use?
Most 2014 ASX variants specify a 1.1 bar (108 kPa) cap. Always match the cap to the vehicle’s build and engine code to be safe.

How often should the radiator cap be replaced?
Have it inspected at every service and plan on replacing it about every 3–5 years or 60,000–100,000 km, or sooner if there are cooling-system symptoms.