Parts for your 2006 Subaru Forester-Radiator cap

2006 Subaru Forester radiator cap — what it does and how to look after it

Based on Subaru’s own technical literature — the 2006 Forester Factory Service Manual (Cooling System section) and the Owner’s Manual cautions about opening the cap when hot — this model absolutely uses a pressure-type radiator cap. On non‑turbo 2.5 models it’s fitted on the radiator neck, on turbo XT models the pressure cap is on the alloy header/reservoir tank under the bonnet. Either way, a radiator/pressure cap is relevant and fitted to the 2006 Subaru Forester.

The cap’s job is simple but critical. It seals the cooling system and holds a set pressure so the coolant’s boiling point is raised, keeping things stable on hot days and long hauls. When pressure gets too high, the cap’s relief valve lets excess coolant move to the overflow bottle, as the engine cools, a vacuum valve draws it back in so the radiator stays full. A weak or wrong‑rated cap can cause overheating, coolant loss, or hoses collapsing after shutdown.

Subaru’s service data specifies typical cap ratings of about 108 kPa (1.1 bar) for non‑turbo Forester radiator caps and about 137 kPa (1.4 bar) for turbo models with a header tank. Always match the cap rating, neck style and depth to the vehicle. Genuine or high‑quality aftermarket is the go, and never crack a cap when the engine’s hot — copious steam and burns aren’t worth it.

• Watch for symptoms of a crook cap: coolant pushed into the overflow but not returning after cool‑down, a collapsed upper hose when cold, rising temps at low speed, staining or crust around the cap, or a hardened/cracked rubber seal.

• Practical servicing tips:
  • Inspect the cap every service for seal condition, spring tension and clean seating faces.
  • Pressure‑test the cap if there’s any doubt, replace if it won’t hold spec.
  • Many workshops treat the cap as a low‑cost preventative replacement about every 5 years or 100,000 km, or whenever the cooling system is refreshed.
  • After fitting a new cap, check coolant level over a few heat cycles and top up with the correct Subaru‑approved coolant mix.

Location check: non‑turbo Forester — cap on the radiator filler neck. Forester XT turbo — cap on the alloy header tank near the intake. These details align with Subaru’s Factory Service Manual and Technical Information System guidance.

Does a 2006 Subaru Forester actually have a radiator cap?

Yes. Non‑turbo models use a pressure cap on the radiator, turbo XT models use a pressure cap on the header/reservoir tank. Subaru’s 2006 Forester Factory Service Manual confirms both arrangements as part of the cooling system.

What pressure cap does a 2006 Forester need?

Common Subaru specs are about 108 kPa (1.1 bar) for non‑turbo radiator caps and about 137 kPa (1.4 bar) for turbo header‑tank caps. Always match the rating on the original cap or confirm by VIN in Subaru service data before buying.

Where is the cap located on this model?

On non‑turbo models it’s right on the radiator neck. On the Forester XT turbo, look for the alloy header tank near the top of the engine bay — the pressure cap lives there, while the radiator itself may not have a pressure cap you remove during routine service.