Parts for your 2017 Mitsubishi Asx-Radiator cap

2017 Mitsubishi ASX Radiator Cap — What It Does and When to Replace It

Referencing Mitsubishi’s service literature for the ASX/RVR (Group 14 – Cooling) and OEM parts catalogues for MY2017, this model does use a pressurised cooling-system cap (commonly called a radiator cap). Depending on build and engine, the cap sits on the radiator filler neck or on a pressurised expansion tank, but it serves the same job and is a replaceable service item.

The radiator cap on a 2017 Mitsubishi ASX quietly does a lot of heavy lifting. It seals the cooling system, holds a set pressure so the coolant can run hotter without boiling, and manages coolant movement to and from the overflow/expansion bottle as temperatures swing. That pressure control stops localised boiling, helps prevent air pockets, and keeps the engine running at a stable temperature on hot Aussie and Kiwi days, up alpine passes, or in stop–start traffic.

Over time, the cap’s rubber seals can harden and the spring can weaken. When that happens, the system may not hold pressure, which can cause creeping temps, coolant loss, or hoses going oddly soft or collapsing as it cools. It’s the sort of small, inexpensive part that can cause big headaches if ignored.

For the ASX, a sensible approach is to have the cap inspected at every service interval. A technician will check the seal condition, look for staining around the neck, and pressure-test the cap against the spec on the cap label or in the owner’s manual. If there’s any doubt about holding pressure, replace it — caps are affordable, and preventative replacement can save a water pump or radiator down the track.

Handy pointers owners will appreciate:

• Only open the cap when the engine is completely cold. Use a rag and turn it slowly to release any residual pressure.
• Top up with the correct Mitsubishi-specified coolant mixture — don’t mix types or colours.
• Inspect for tell-tales like crusty residue, a cracked gasket, or a cap that spins on too easily — all signs it’s time to swap it.

Cap pressure ratings can vary by engine and market, so match the replacement to the label on the original cap or the parts catalogue listing for the 2017 ASX. Fit the new cap snugly, confirm the overflow hose is tight and crack-free, and keep an eye on the coolant level over the next few drives. It’s a five-minute job that helps the ASX stay cool and happy for many kilometres.

Popular questions about the 2017 Mitsubishi ASX radiator cap

Where is the radiator cap on a 2017 Mitsubishi ASX?
On many ASX models it’s on the radiator filler neck near the upper hose, some builds use a pressurised expansion tank with the cap on the bottle. If in doubt, follow the top radiator hose or check the cooling layout in the owner’s manual.

What pressure cap does the ASX use?
The correct pressure rating is printed on the cap and listed in the Mitsubishi parts catalogue for your VIN. Always match that spec — using the wrong rating can cause overheating or unwanted coolant loss.

How often should the radiator cap be replaced?
Have it checked at each service and replace it at the first sign of leaking, damaged seals, or a failed pressure test. Many owners choose proactive replacement when doing a coolant change for peace of mind.