Parts for your 2013 Subaru Tribeca-Radiator cap

2013 Subaru Tribeca radiator cap — purpose, servicing and handy tips

Based on technical sources, a radiator cap is indeed fitted and relevant on the 2013 Subaru Tribeca. This is supported by Subaru’s 2013 Tribeca Owner’s Manual (Cooling System guidance and warnings about removing the radiator cap only when cool), Subaru’s FAST parts catalogue listing a “Cap, Radiator” for the 2013 Tribeca (common genuine part number series 45137AE0xx), and the Subaru service manual for the EZ36 engine, which specifies radiator cap inspection and an opening pressure around 137 kPa. Together these sources confirm the vehicle uses a conventional pressurised radiator cap.

For the 2013 Tribeca, the radiator cap plays a bigger role than most drivers realise. It seals and pressurises the cooling system to a set rating (about 137 kPa/1.4 bar on the H6), lifting the coolant’s boiling point so the engine can run at proper temperature without bubbling over. It also manages coolant flow between the radiator neck and the overflow bottle as the engine heats and cools, maintaining the right level in the system.

As part of regular servicing, it’s smart to treat the cap as a service item. Rubber seals harden, springs weaken, and the little vacuum valve can stick. Any of those can lead to slow coolant loss, hot running in traffic, weak cabin heat, or hoses that collapse after cooldown. If the Tribeca’s cooling system is otherwise sound but it’s still misbehaving, a tired cap is often the cheap fix.

Replacement is straightforward, but patience is key. Always let the engine cool completely. Wrap a rag over the cap, press down and turn to release any residual pressure, then remove. Wipe the filler neck clean and check for nicks or corrosion. Fit a quality cap with the correct pressure rating—ideally a genuine Subaru or reputable equivalent—and ensure it seats squarely. After refilling/bleeding coolant, confirm the overflow bottle sits between the markers when cold.

During routine services (every 12 months or 15,000 km is common in AU/NZ), the cap should be inspected and pressure-tested. Many owners choose to replace it proactively every 4–5 years or around 80,000–100,000 km, or any time there are cooling-system concerns.

• Tell-tales of a dodgy cap: creeping temps, coolant smell without clear leaks, gurgling after shut-down, or a top hose that feels unusually soft or collapses when cold.
• Use Subaru-approved long-life coolant and keep the overflow bottle between MIN and MAX when cold.
• Never open the cap hot—wait until it’s stone cold under the bonnet.

Where is the radiator cap on a 2013 Subaru Tribeca?

It’s on the radiator’s filler neck at the front of the engine bay. Pop the bonnet and look near the top tank of the radiator. The overflow bottle sits nearby and is non-pressurised.

What pressure rating should the Tribeca’s radiator cap have?

Subaru specifies a high-pressure cap for the EZ36 H6, typically around 137 kPa (about 1.4 bar). Always match the cap rating to the factory spec printed on the original cap or confirm with genuine parts information.

How often should the radiator cap be replaced?

Inspect it at each service and pressure-test if any cooling issues crop up. Many technicians in Australia and New Zealand replace the cap about every 4–5 years or 80,000–100,000 km, or sooner if the seal is perished, the spring is weak, or there are overheating symptoms.