Parts for your 1986 Mitsubishi Pajero-Tx valve

1986 Mitsubishi Pajero TX Valve — What it does and how to look after it

Based on technical references, the 1986 Mitsubishi Pajero (first‑generation L040 series) is fitted with a thermostatic expansion valve (TXV). The Mitsubishi factory service manuals for the mid‑80s Pajero/Montero HVAC section illustrate a TXV at the evaporator inlet, and the Mitsubishi ASA electronic parts catalogue lists an A/C expansion valve for these models. That means a TX valve is absolutely relevant to the 1986 Pajero’s factory air‑conditioning system.

The TX valve meters liquid refrigerant into the evaporator, reacting to evaporator outlet temperature and pressure to keep superheat in the sweet spot. For a 1986 Pajero running the original DENSO‑type system, that steady metering is what prevents icing on cold days and slushy, warm air on hot days. When the TXV sticks shut, cools erratically, or overfeeds, the cabin comfort goes out the window and compressor health can suffer.

Owners often notice tell‑tales like weak cooling at idle, evaporator icing behind the dash, a hunting compressor, or pressure readings that are wildly off. If contamination or moisture has been through the system, the TXV’s tiny passages and power element can be the first casualties.

Good servicing practice for this Pajero includes treating the TX valve as part of a system, not an isolated widget. When replacement is on the cards, it’s smart to pair it with a fresh receiver‑drier and new O‑rings, and to flush lines and the condenser if debris is suspected. Any work that opens the A/C loop in Australia or New Zealand must be handled by a licensed technician, refrigerant recovery, evacuation and recharge are not DIY jobs.

• Access is typically at the evaporator case behind the glovebox, the TXV sits at the evaporator inlet with a sensing bulb clamped to the outlet pipe.
• Insulate the sensing bulb properly and refit it in the original position, poor bulb contact makes the TXV misbehave.
• Use the correct oil type and volume for R12‑original systems that have been converted to R134a (ester oil is commonly chosen for retrofits).
• Always pull a deep vacuum and verify it holds before charging to the specified weight.

For Pajeros still on original hoses, consider barrier‑type replacements during a TXV job to reduce refrigerant seepage. Get the basics right and the old girl’s A/C will blow cold without dramas, even in a stinking hot Aussie or Kiwi summer.

Popular questions about the 1986 Mitsubishi Pajero TX valve

Where is the TX valve located on a 1986 Pajero?
It’s mounted at the evaporator inlet inside the HVAC case, typically behind the glovebox area. Access usually means removing trim to reach the evaporator housing and disconnecting the A/C lines at the firewall before unbolting the valve.

What are common signs the TX valve needs replacement?
Common signs include weak or fluctuating cooling, evaporator icing, a compressor that cycles rapidly, and abnormal high/low‑side pressures during gauge testing. Contamination or moisture in the system can also jam the valve, leading to poor performance.

Should the receiver‑drier be replaced with the TX valve?
Yes. On these TXV/receiver‑drier systems, replacing the drier whenever the circuit is opened is best practice. It traps moisture and debris that can damage the new valve and compressor, and helps ensure long‑term reliability after a recharge.