Parts for your 1997 Mitsubishi Pajero-Tx valve

1997 Mitsubishi Pajero TX Valve — What It Does and How to Look After It

Yes, the 1997 Mitsubishi Pajero is fitted with a thermostatic expansion (TX) valve in its R134a air-conditioning system. This is shown in Mitsubishi’s factory Workshop Manual for Pajero/Montero (Heating & Air Conditioning section, 1997 edition) and the Mitsubishi ASA Electronic Parts Catalogue for 1997 V4#/V6# models, which list a “VALVE, EXPANSION (FRONT)” and, on dual A/C vehicles, a separate rear expansion valve.

The TX valve’s job is to meter refrigerant into the evaporator so the system cools hard without icing up. It reads evaporator outlet temperature and pressure via a sensing bulb and diaphragm, adjusting flow so the evaporator runs at the sweet spot. On Pajero models with rear air, there’s a second TX valve serving the rear evaporator. When the valve sticks or clogs, you’ll usually get weak cooling, vent temps that wander, frosting at the evaporator or lines, or odd pressure readings.

During servicing, the TX valve isn’t a regular “wear” item, but it should be assessed any time the A/C is open or performance is off. A licensed air-con tech should confirm correct charge weight for R134a, run a performance and pressure test, and check the valve’s bulb mounting and insulation at the evaporator. If there’s been compressor failure or debris (“black death”), best practice is to replace the TX valve and receiver-drier, flush lines where approved, fit new O-rings, evacuate thoroughly, and recharge to spec with the correct PAG oil balance.

• Typical failure clues: poor cooling at idle or all the time, evaporator freeze-up, erratic low-side pressure, or a hissing/whistling at the firewall area.
• Good habits: use new sealing washers/O-rings, follow the workshop manual torque specs, keep everything surgically clean, and re-wrap the sensing bulb with proper insulation.

On the ’97 Pajero, the front TX valve sits on the evaporator block behind the glovebox (at the firewall connections). Removal means dropping the glovebox and opening the evaporator case, rear A/C valves live near the rear evaporator assembly. Given the age of these trucks, corrosion at the flare nuts and aged O-rings are common—soak fixings with penetrant and replace seals as a matter of course. Look after the TX valve and it’ll reward the cabin with steady, frosty air through Aussie summers and Kiwi road trips alike.

Popular questions about 1997 Mitsubishi Pajero TX valve

Where is the TX valve located on a 1997 Pajero?
The front TX valve is mounted on the evaporator core behind the glovebox, right where the A/C pipes pass through the firewall. On models with rear air, a second valve is fitted at the rear evaporator assembly, typically in the rear quarter area. Access generally involves removing trim and opening the evaporator case.

What are the signs the TX valve is failing?
Think inconsistent cooling, vents going cold then warm, frosting on the evaporator or lines, and unusual gauge readings (low suction when restricted, high suction when stuck open). A competent diagnostic with temperature and pressure checks will confirm whether it’s the valve or something upstream like charge level or the compressor.

Should the TX valve be replaced when changing the compressor?
It’s strongly recommended if the old compressor failed internally or there’s contamination. Replace the receiver-drier, flush where approved, fit a new TX valve, renew O-rings, evacuate, and recharge to the specified R134a weight. This prevents debris from compromising the fresh compressor and restores proper metering.