Parts for your 2019 Nissan Pathfinder-Radiator cap

2019 Nissan Pathfinder radiator cap — what it does and how to look after it

Based on technical documentation, the 2019 Nissan Pathfinder (R52, VQ35DE) is fitted with a radiator pressure cap and it is relevant to normal servicing. The Nissan Pathfinder 2019 Model Year Service Manual (R52), Cooling System (CO) section, lists a radiator cap with a specified opening pressure and outlines cap inspection/testing. The 2019 Pathfinder Owner’s Manual also cautions against removing the radiator cap when hot, indicating it’s a serviceable component. Common parts catalogues for this model list compatible pressure caps, further confirming fitment.

On this Pathfinder, the radiator cap’s job is to seal and pressurise the cooling system so coolant runs hotter without boiling, keeps air out, and moves excess coolant to the reservoir when things heat up. As the engine cools, it lets coolant return from the reservoir, keeping the system topped up. If the cap’s spring or seals get tired, owners may see slow overheating, coolant loss, hard upper hoses, or even collapsed lower hoses after cool-down.

Servicing the radiator cap is simple and worth doing. Under the bonnet, the cap sits on the radiator neck at the front (a trim cover may need to be lifted). Only remove it when the engine is stone cold. Use a rag, turn to the first notch to bleed any residual pressure, then remove fully. Check that the rubber seals aren’t cracked, the seat isn’t pitted, and the spring offers firm resistance. A cooling-system pressure tester can verify the cap’s rating holds steady under load.

• Recommended cap rating: typically around 108 kPa (1.1 bar, ~16 psi) for this model, always match the spec on the original cap or as per the Service Manual.
• Inspect at every service (or at least annually/20,000 km), and replace straight away if there’s any doubt.
• Good times to renew the cap: when doing a coolant flush, after an overheating event, or if there’s dried coolant crust around the neck or cap.
• Refit to a clean filler neck, tighten to full lock, and ensure the overflow hose is snug and crack-free.

Coolant choice matters too. Use the correct Nissan blue long-life coolant mixed to spec, and bleed air as per workshop procedure after any cooling-system work. A quality, correctly rated cap is cheap insurance for the Pathfinder’s V6.

Popular questions about the 2019 Nissan Pathfinder radiator cap

Where is the radiator cap on a 2019 Pathfinder?
It’s on the radiator’s top tank at the very front of the engine bay. On some trims there’s a plastic shroud you’ll lift to see it clearly. Always check and remove it only when the engine is completely cold.

What pressure rating cap does it use?
Most 2019 Pathfinders use a cap around 108 kPa (1.1 bar, ~16 psi). Match what’s printed on the original cap or follow the figure in the Nissan Service Manual for your VIN/market.

How often should the radiator cap be replaced?
There’s no hard interval, but inspecting it at each service is smart. Many owners replace the cap during a coolant service or around 100,000 km, and immediately if a pressure test fails or the seals look tired.