Parts for your 2008 Subaru Forester-Heater hose

2008 Subaru Forester heater hose — purpose, service and replacement

A heater hose is definitely relevant and fitted to the 2008 Subaru Forester. Factory documentation confirms it: the Subaru Factory Service Manual (via Subaru’s Technical Information System) shows two heater hoses running from the EJ-series engine to the heater core at the firewall, typically labelled heater hose A and heater hose B. The Subaru FAST electronic parts catalogue also lists dedicated inlet and outlet heater hoses for the 2008 Forester range (non‑turbo and turbo). Major aftermarket catalogues in Australia and New Zealand likewise list direct-fit heater hoses for this model, which reinforces their presence and serviceability.

On this Forester, the heater hoses circulate hot coolant from the engine through the heater core, letting cabin air warm up on cold mornings without overworking the demister. They also form part of the broader cooling system loop, so any weakness can lead to leaks, overheating, or a steamy windscreen when you least expect it.

Given the age of a 2008 vehicle, original hoses are well past their best. During routine servicing, a technician should squeeze‑test the hoses for softness, check for cracking, glazing, swelling from oil contamination, and look for coolant staining near the firewall connections. It’s smart practice to inspect at every service and plan replacement around the 8–10 year/160,000 km mark, or sooner if there’s any doubt.

When replacement is due, it pays to do both heater hoses as a pair and use quality moulded hose with constant‑tension clamps. With the engine stone‑cold, drain enough coolant to drop the level below the heater hose stubs, mark the hose orientation, and remove the old clamps and hoses. Clean the nipples on the engine and firewall, fit the new hoses fully seated, and position clamps away from any chafe points. Refill with the correct Subaru‑approved coolant at a 50/50 mix with demineralised water (many 2008 models were specified for long‑life blue coolant in AU/NZ