Parts for your 2017 Subaru Forester-Tx valve

2017 Subaru Forester TX-valve: what it does and when to service it

Referencing technical sources including the Subaru Forester (SJ) Service Manual – HVAC Air Conditioning section, Subaru’s Technical Information System (STIS), and mainstream OEM/aftermarket parts catalogues listing an A/C expansion valve for the 2017 Forester, this model is fitted with a thermostatic expansion valve (TX‑valve) at the evaporator.

The TX‑valve is the little metering brain of the Forester’s air‑con. It regulates how much liquid refrigerant is fed into the evaporator based on temperature and pressure, keeping evaporator superheat in the sweet spot. That means cold air at the vents without freezing the core, stable cabin temps on long Kiwi and Aussie drives, and a compressor that isn’t working harder than it should.

As a service item, the TX‑valve isn’t normally replaced on a schedule. It’s checked when there are symptoms like weak cooling at idle but cold on the highway, vent temps that swing hot‑cold, evaporator icing, or pressure readings that don’t make sense on the gauges. If the A/C system has been opened up (say, condenser or compressor replacement), the TX‑valve may be inspected or replaced if contamination is suspected.

• Common signs a TX‑valve is playing up: frosting at the evaporator or TX‑valve body, hissing followed by poor cooling, very high or very low low‑side pressure, or metal/debris found in the system.
• Good practice during related A/C work: always replace the receiver/drier or desiccant bag when the system’s opened, renew O‑rings and lightly oil them with the correct PAG oil, evacuate thoroughly, and recharge to the label specification.

Replacement and recharging must be done by a licensed A/C technician (ARCtick in Australia or the local equivalent in New Zealand). They’ll recover the refrigerant, access the evaporator housing, remove the valve and lines, fit new seals, and torque fasteners to Subaru specifications. After refit, they’ll vacuum test, recharge with the correct refrigerant type and mass shown on the under‑bonnet label, and verify performance and leak‑tightness.

Owners can help the TX‑valve live a long, drama‑free life by keeping the cabin filter fresh, ensuring condenser fins are clean and straight, and running the A/C regularly year‑round to keep seals lubricated. If the system’s ever contaminated (for example, after a compressor failure), a deeper clean, drier replacement, and sometimes TX‑valve replacement are the smart moves to protect the rest of the hardware.

Does the 2017 Forester use a TX‑valve or an orifice tube?

It uses a thermostatic expansion valve mounted at the evaporator. This is confirmed in Subaru’s SJ Forester service information and common parts catalogues that list an A/C expansion valve for the 2017 model.

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

Think inconsistent vent temps, icing on the evaporator or valve, weak cooling at idle, or pressure readings that are way off. A licensed tech can confirm with gauge readings and temperature measurements across the evaporator to check superheat.

Should the TX‑valve be replaced whenever the A/C is serviced?

No. It’s not a routine replacement item. It’s typically replaced if it’s sticking, leaking, or there’s contamination. Whenever the system is opened, replace the receiver/drier (or desiccant bag), renew O‑rings, and recharge to the exact label spec.