Parts for your 2010 Subaru Outback-Tx valve

2010 Subaru Outback TX valve: what it does, and how to look after it

Yes, a TX valve (thermal expansion valve) is fitted to the 2010 Subaru Outback. This is confirmed by the Subaru Factory Service Manual for the 2010 Outback/Legacy (HVAC-Air Conditioning section, which illustrates an “Expansion Valve” at the evaporator inlet) and by Subaru genuine parts catalogues listing an “Expansion Valve Assy” for this model year (commonly referenced as 73520AJ00A/73520AJ01A). These technical sources identify the TX valve as the metering device in the Outback’s R134a air-con system.

On this model, the TX valve’s job is to precisely meter refrigerant into the evaporator based on temperature and pressure, keeping the evaporator at the sweet spot for strong cooling without freezing. When it’s working right, cabin temps pull down quickly, vent temps stay stable, and the compressor isn’t overworked.

Typical signs the TX valve is on the way out include weak cooling at idle but better on the move, frost or sweat on one line but not the other at the firewall, hunting compressor cycling, or a noticeable hiss/gurgle from the dash after shutdown. A valve that’s stuck open can flood the evap, stuck closed can starve it. Either way, performance drops and the system can run hot or icy.

• Service reality: the TX valve isn’t a routine maintenance item. It’s replace-on-fault or while you’re in there for major work (e.g., compressor replacement, black death/contamination, or after a long-term leak).
• Best practice when opening the system: renew the TX valve O-rings, replace or service the receiver/drier or desiccant pack in the condenser, evacuate thoroughly, and charge by weight with the specified R134a and PAG oil per the Subaru manual.
• Access: it’s mounted at the evaporator in the HVAC case (behind the glovebox area). Lines must be disconnected at the firewall side, expect some dash-side access time.
• Compliance: in Australia and New Zealand, refrigerant handling must be done by a licensed air-conditioning technician (e.g., ARCtick in AU). Venting refrigerant is illegal and unsafe.

If the system’s been contaminated (compressor failure, dark oil, debris), a new TX valve helps prevent repeat issues. After installation, a deep vacuum and a precise recharge are critical. A healthy TX valve, paired with a clean system and correct charge, keeps the Outback’s air-con crisp even on those stinking hot summer runs.

Popular questions about the 2010 Subaru Outback TX valve

Where is the TX valve on a 2010 Subaru Outback?

It’s fitted at the evaporator inlet inside the HVAC box behind the dash (glovebox side), with the refrigerant lines passing through the firewall. Access typically involves glovebox removal and disconnecting the engine-bay lines at the bulkhead.

What symptoms point to a failing TX valve on this model?

Common giveaways are poor cooling at idle, big swings in vent temperature, frosting on one line at the firewall, or rapid compressor cycling. If charge level and condenser airflow check out, the metering valve is a prime suspect.

Should the TX valve be replaced when changing the compressor?

It’s strongly recommended if the old compressor failed or the system shows contamination. Pair it with fresh O-rings and a serviced receiver/drier or desiccant pack, then evacuate and recharge to the Subaru-specified mass of R134a.