Parts for your 2018 Toyota C-hr-Tx valve

2018 Toyota C‑HR TX Valve — what it is, where it lives, and how to look after it

For the 2018 Toyota C‑HR, a TX valve (thermal expansion valve) is absolutely relevant and fitted. Toyota’s own service literature for the C‑HR (Air Conditioning: Cooler Expansion Valve — Removal/Installation/Inspection) details the valve at the evaporator, and the Toyota Electronic Parts Catalogue under Heating & Air Conditioning lists a “cooler expansion valve (for evaporator)” for this model. DENSO technical guidance for TXV‑type systems also aligns with how the C‑HR’s air‑con meters refrigerant flow.

On this car, the TX valve is the metering device that controls how much liquid refrigerant enters the evaporator. It reacts to evaporator outlet temperature and pressure to maintain correct superheat, keeping cabin cooling stable while protecting the compressor from liquid slugging. When it’s healthy, owners get quick pull‑down on hot days, steady vent temps at idle, and efficient operation whether stuck in traffic or cruising the motorway.

There’s no scheduled replacement for the TX valve, it’s serviced on condition. If work is needed, it’s a block‑style valve mounted at the evaporator, accessed from the cabin side (behind the glovebox area on most trims). Proper service steps include recovering the refrigerant, capping open lines to keep moisture out, renewing O‑rings, evacuating to deep vacuum, and recharging by weight. Where the C‑HR’s condenser uses an integrated desiccant bag, that bag (or the condenser if non‑serviceable) should be replaced if the system’s been open or contaminated. Always match the refrigerant and oil shown on the under‑bonnet label (markets may be R‑134a or R‑1234yf, wrong fill will upset performance and reliability).

• Common TX valve clues: weak cooling at idle but better on the move, frosty or sweating evaporator lines, vent temps that hunt, hissing at the case, and pressure readings that are too high or too low for the ambient.
• Good practice: keep everything surgically clean, torque fittings to spec from the Toyota manual, nitrogen pressure‑test before vacuum, and avoid mixing PAG oils.
• If a compressor has failed, check for debris. Flushing lines, replacing the desiccant, and often the TX valve is smart insurance.

A licensed air‑con specialist with Toyota‑approved procedures and equipment will save headaches and help the C‑HR’s TX valve do its job for the long haul.

Where is the TX valve on a 2018 Toyota C‑HR?

It’s a block‑type valve mounted at the evaporator inlet, inside the cabin on the HVAC case (behind the glovebox area on most variants). The refrigerant pipes pass through the firewall to this valve. Access typically involves removing trim and the glovebox to reach the valve and pipe unions.

Does the C‑HR use R‑134a or R‑1234yf, and does that affect the TX valve?

Depending on market and build date, it may use either. Always follow the refrigerant label under the bonnet. The TX valve and oil choice are matched to the refrigerant, using the wrong gas or oil can harm performance and component life.

Should the TX valve be replaced when fitting a new compressor?

Not automatically, but it’s often recommended if the old compressor shed metal or the system was contaminated. Combine the job with line flushing where applicable, new O‑rings, and a fresh desiccant bag (or condenser if the bag isn’t serviceable) to protect the new compressor.