Parts for your 2015 Subaru Forester-Tx valve

2015 Subaru Forester TX Valve — what it does, where it lives, and when to sort it out

Yes, the 2015 Subaru Forester (SJ) uses a thermal expansion valve (TX valve/TXV) in its air-conditioning system. Subaru’s factory service information (STIS – HVAC: Air Conditioner > Refrigerant Line > Expansion Valve) specifies a TXV fitted at the evaporator inlet, and the Subaru parts catalogue lists Valve Complete–Expansion for this model (commonly OEM p/n 73520SG000, superseded in some listings by 73520SG010). Reputable aftermarket catalogues also supply an A/C expansion valve for the 2015 Forester, which aligns with the Subaru service manual description.

On the 2015 Forester, the TX valve meters the exact amount of R‑134a refrigerant entering the evaporator based on temperature and pressure, keeping evaporator “superheat” in the sweet spot. That means strong, stable cabin cooling without flooding the compressor with liquid. When the TXV is healthy, the system cools quickly at traffic lights and on the motorway, with minimal cycling and no icy evaporator core.

Typical signs the TXV is crook include weak cooling at idle but cooler air at speed, evaporator or line frosting, rapid compressor cycling, a hissing or whooshing at the firewall area, and gauge readings that show very high or very low superheat. Contamination from a failed compressor or moisture in the system can make the valve stick or clog.

There’s no routine “maintenance” for a TXV, but it should be inspected whenever the A/C is open or performance drops. If the system has been apart, best practice is to replace the receiver–drier (desiccant is integrated in the condenser on many SJ Foresters) and fit new O‑rings lubricated with the specified PAG oil (ND‑OIL 8 / PAG 46). Because handling refrigerant is regulated in Australia and New Zealand, recovery, evacuation and re‑gassing must be done by a licensed air‑con technician.

Replacement generally involves recovering refrigerant, disconnecting the A/C lines at the firewall, accessing the TXV at the evaporator connection (behind the glovebox/HVAC case area), swapping the valve and O‑rings, then evacuating and recharging to the correct weight. It’s a tidy job to combine with evaporator cleaning and a fresh cabin filter to keep airflow up and icing down. If the compressor has failed, a full clean-out, new TXV and new condenser/drier are strongly recommended to protect the new gear.

• Handy checks: look for oily residue at fittings, confirm condenser fans run, and verify charge by weight, not just pressures.
• When unsure, a licensed technician can pressure-test with nitrogen and confirm TXV operation via superheat and temperature-drop measurements.

Popular questions

Does the 2015 Subaru Forester use a TX valve or an orifice tube?
It uses a thermal expansion valve mounted at the evaporator inlet. This is documented in Subaru’s STIS service manual and reflected in OEM parts listings for the Forester SJ series.

What are the common signs the TX valve is failing on a 2015 Forester?
Weak cooling at idle, intermittent cold air, line or evaporator frosting, rapid compressor cycling, and odd pressure readings are common clues. A sticking or contaminated valve is often to blame, especially after a compressor issue.

Can a home mechanic replace the TX valve?
Physical access is doable with trim and HVAC know‑how, but recovering and recharging refrigerant must be done by a licensed air‑conditioning technician in Australia and New Zealand. Most owners team up with a pro for the refrigerant work.