Parts for your 2000 Nissan Navara-Tx valve

2000 Nissan Navara TX‑valve: what it is, where it lives, and how to look after it

Based on Nissan’s own service literature and parts catalogues, the 2000 Navara (D22 series) air‑conditioning system uses a thermal expansion valve (TX‑valve). The valve is a block‑type unit mounted at the evaporator inlet, with a receiver‑drier in the high‑side—typical of TXV systems. Technical sources include the Nissan D22 Workshop Manual, Heater & Air Conditioning (HA) section for 1999–2001, and the Nissan FAST/Group 27 parts catalogue listings for the D22 showing an A/C Expansion Valve applicable to 2000 model year vehicles.

On a 2000 Navara, the TX‑valve basically meters how much refrigerant gets into the evaporator. It reacts to temperature and pressure, keeping the evaporator cold enough to chill the cabin air without icing up. In plain terms, it stops the air‑con from running hot on a scorcher or freezing its socks off on a cool morning. Because it sits right at the evaporator, it’s a key control point for stable vent temps and compressor workload.

Tell‑tale signs the TX‑valve’s not happy include erratic cabin temps, frost on the low‑pressure line near the firewall, weak cooling at idle but better at speed, or the compressor cycling heaps. On the gauges you might see a starved evaporator (low low‑side, lowish high‑side) or flooding (high low‑side, low superheat). Keep in mind other faults—like a blocked drier or weak compressor—can mimic TXV issues.

There’s no real “service” for the valve itself, but good air‑con maintenance helps it live longer: keep the system clean and dry, replace the receiver‑drier whenever the circuit’s opened, and use the correct oil and gas. For this era Navara, the system is R134a and typically uses Nissan ND‑OIL 8 (PAG 46), always confirm on the under‑bonnet label.

When replacement’s on the cards, it’s a job for a licensed A/C tech in AU/NZ because refrigerant recovery and re‑gassing are regulated. Best‑practice steps include:

• Recover refrigerant, then remove the evaporator/TX‑valve assembly (access is behind the glovebox on most D22s).
• Fit a quality replacement valve, new O‑rings lubricated with the correct PAG oil, and refit any insulation/foam around the valve.
• Replace the receiver‑drier, evacuate to deep vacuum, verify it holds vacuum, then charge by weight with R134a.
• Check superheat and pressures, confirm vent temps, and leak‑test with nitrogen and/or electronic detection.

Done right, a fresh TX‑valve and drier can bring the Navara’s air‑con back to crisp, reliable performance—just what’s wanted for a hard‑working ute.

Technical references

• Nissan D22 Series (Navara/Frontier) Workshop Manual, Heater & Air Conditioning (HA) section, 1999–2001 editions.
• Nissan FAST Parts Catalogue, Group 27 – Heater & Air Conditioner, D22 application listing “A/C Expansion Valve”.
• Factory service data for Nissan Frontier (D22), HA section, covering TXV‑type evaporator inlet valve and receiver‑drier system layout.

Popular questions about 2000 Nissan Navara TX‑valve

Where is the TX‑valve on a 2000 Navara?
It’s a block‑type valve mounted at the evaporator inlet. Access is typically from inside the cabin behind the glovebox where the evaporator case sits, with pipe connections visible at the firewall in the engine bay.

Can a sticking TX‑valve be cleaned, or does it need replacing?
If a TX‑valve is sticking due to moisture, debris, or internal wear, replacement is the reliable fix. The system should be evacuated, the receiver‑drier replaced, and the circuit flushed if contamination’s suspected before re‑gassing.

What refrigerant and oil does it use?
The D22 Navara of this vintage uses R134a refrigerant. The specified oil is Nissan ND‑OIL 8 (PAG 46). Always verify on the under‑bonnet label or service manual for your exact variant.