Parts for your 2011 Nissan Pathfinder-Tx valve

2011 Nissan Pathfinder TX Valve: what it does and how to look after it

Based on the Nissan 2011 Pathfinder (R51) Service Manual — HA: Heater & Air Conditioner, which details “Expansion Valve” removal/installation — and multiple parts catalogues that list a front expansion (TX) valve and an additional rear valve on seven-seat rear A/C models, the 2011 Pathfinder is fitted with a TX valve. These technical sources confirm the TX valve is relevant to this vehicle, with rear A/C-equipped Pathfinders using two valves.

The TX valve’s job is to precisely meter refrigerant into the evaporator so the air-con cools hard without flooding the core. It reacts to evaporator outlet temperature via its sensing bulb and keeps superheat in the sweet spot, which protects the compressor and keeps cabin temps stable on stinking hot days. On the R51, the front TX valve is mounted at the evaporator in the dash, models with rear climate get a second valve back near the rear evaporator assembly.

There’s no set replacement interval, but the TX valve is a wear-and-tear item. It should be replaced if it’s sticking, blocked with debris/moisture, or leaking, and any time the system is contaminated (for example after a compressor failure). Handy signs it’s time to investigate:

• Warm air at idle but icy when driving, or temps that swing hot–cold
• Abnormal high/low side pressures, line frosting at the valve, or hissing/whistling
• Oil stains around the valve fittings, or poor rear cooling when only the rear circuit is on

Good servicing practice on a 2011 Pathfinder includes a licensed air-con tech lawfully recovering R134a, opening the HVAC case to access the valve, and renewing the receiver/drier whenever the system’s opened. Fresh O-rings should be used and lightly lubricated with the correct oil, then everything torqued to spec. After refit, the system needs an extended vacuum to boil off moisture, a recharge by weight, and a leak/effectiveness check. If your Pathfinder has rear A/C and performance is weak, both the front and rear TX valves and the long refrigerant lines should be assessed together.

For longevity, keep the condenser clean of bugs and fluff, replace the cabin filter on time to maintain airflow across the evaporator, and insist on the right spec PAG oil and dye only as per the service label under the bonnet. When the compressor is replaced, plan on a TX valve and drier as part of a proper job.

Popular questions about 2011 Nissan Pathfinder TX valves

Do all 2011 Pathfinders have two TX valves?
Not all. Every R51 Pathfinder has a front TX valve. Models equipped with rear air-conditioning (common on seven-seaters) also have a second, rear TX valve at the rear evaporator. If rear cooling is weak while the front is fine, that rear valve may be the culprit.

What refrigerant does the 2011 Pathfinder use?
From factory it runs R134a. Always confirm on the under‑bonnet air-con label and follow the Service Manual specs for charge weight and PAG oil type/quantity. Sticking to the correct fill by weight is critical for TX valve performance.

When should the TX valve be replaced?
There’s no fixed interval. Replace it if it’s sticking, blocked, or leaking, when a compressor has failed, or whenever contamination or moisture is suspected. It’s smart to pair TX valve and receiver/drier replacement to keep the system clean and reliable.