Parts for your 1997 Nissan Navara-Tx valve

1997 Nissan Navara TX Valve — What it does and how to look after it

Based on technical references including the Nissan Navara D22 Factory Service Manual (1997, Section HA – Air Conditioner), the Nissan FAST parts catalogue for D22 (listing “Valve Assy–Thermo” at the evaporator), and Denso/aftermarket parts data for the D21/D22 platform, the 1997 Nissan Navara is equipped with a thermostatic expansion valve (TX valve). It’s mounted at the evaporator inlet and the system uses a receiver–drier rather than an orifice-tube/accumulator layout, making the TX valve a relevant, fitted component on this model.

On a 1997 Navara, the TX valve meters liquid R134a into the evaporator and maintains correct superheat. That keeps the evaporator cold without freezing, stabilises vent temperatures, and helps the compressor live a long life. In Aussie and Kiwi heat, a healthy TX valve is the difference between chilly air and a sweaty commute.

There’s not much “maintenance” for a TX valve beyond system hygiene. It’s a precision metering device, so contamination is its worst enemy. When the A/C circuit is opened, replacing the receiver–drier, renewing all disturbed O-rings, and pulling a deep vacuum are must‑dos. If performance is off—slow cooldown, frosty lines at the firewall, hunting vent temps, or a high/low side pressure imbalance—diagnosis should include the TX valve.

Access on the D22 typically means working at the evaporator case behind the glove box. A qualified tech will recover the refrigerant, split the evaporator fittings using two spanners to avoid twisting the pipes, swap the valve and O-rings, insulate the bulb and lines properly, evacuate to at least 500 microns, and recharge by weight to the OEM spec with the correct PAG oil balance. By law in AU/NZ, refrigerant work must be performed by a licensed person.

• Replace the TX valve when the system has metallic debris, the valve is stuck (overfeeding or starving), or after compressor failure.
• Always fit a new receiver–drier, flush where appropriate, and add UV dye to help spot future leaks.
• Avoid “cleaning” a faulty TX valve—replacement is the reliable fix.

With proper installation and a clean, dry system, the Navara’s TX valve will quietly keep cabin temps spot‑on for years.

Does the 1997 Navara use a TX valve or an orifice tube?

It uses a TX valve. The Nissan D22 HVAC design shows a thermostatic expansion valve at the evaporator with a receiver–drier in the liquid line. Parts catalogues for the D22 list the TX valve assembly specifically, confirming the configuration.

What are common symptoms of a failing TX valve on a ’97 Navara?

Expect weak or intermittent cooling, frosting at the evaporator inlet or firewall, vent temps that swing hot–cold, and abnormal gauge readings (high high-side with low low-side if it’s restricted, the reverse if it’s stuck open). Professional diagnosis is recommended to rule out low charge or a weak compressor.

Can the TX valve be serviced instead of replaced?

Not realistically. If the system is contaminated or the valve is sticking, replacement is the dependable route. Pair it with a new receiver–drier, correct oil balancing, and a precise recharge for long-term reliability.