Parts for your 1998 Mitsubishi Pajero-Tx valve

1998 Mitsubishi Pajero TX Valve — What it does and when to replace it

For the 1998 Mitsubishi Pajero fitted with factory air conditioning, a thermostatic expansion valve (TX valve/TXV) is used, not an orifice tube. This is documented in Mitsubishi’s Pajero V20 series workshop manual (Heating & Air Conditioning, Group 55) and shown in the Mitsubishi ASA electronic parts catalogue, both identifying a TXV mounted at the evaporator. The DENSO system fitted to Pajero models of this era also specifies a TXV at the evaporator inlet to control refrigerant flow and superheat.

The TX valve’s job is to meter R134a into the evaporator based on outlet temperature/pressure, keeping the evaporator cold without icing and giving consistent cabin temps. By regulating superheat, it protects the compressor from liquid slugging and helps the A/C pull strong at idle on hot Aussie and Kiwi days.

It’s worth a look if the aircon’s gone a bit average. Typical clues include:

• Warm air at idle but better cooling on the open road
• Evaporator or suction line frosting, then sudden warm air
• Hunting/cycling pressures, noisy hiss at the dash, or poor pull-down
• After a compressor burn-out or system contamination

Replacement on a 1998 Pajero means working at the evaporator block behind the glovebox. The system must be properly recovered, not vented. Best practice for this vehicle is to replace the TXV with new O-rings, renew the receiver–drier, and flush lines if contamination is suspected. Then evacuate for an adequate vacuum hold, perform a leak test, and recharge with the R134a quantity shown on the under‑bonnet label. Tighten fittings to the workshop manual spec and add the correct PAG oil balance for any parts changed. Given Australian and New Zealand regulations, this work should be handled by an ARCtick-licensed A/C technician.

To keep the TX valve happy between services, run the A/C regularly, keep the condenser clean of bugs and grass seeds, and check cabin filtration if your Pajero is fitted with a pollen filter. If cooling falls off, a quick performance test and pressure check can catch a sticky TXV early before it takes out the compressor.

• Does a 1998 Pajero use a TX valve or an orifice tube?

The 1998 Pajero uses a thermostatic expansion valve at the evaporator, not an orifice tube. This layout is shown in Mitsubishi’s service literature and parts catalogues for the V20 series, and aligns with DENSO’s TXV-type systems used on Japanese 4x4s of that era.

• Where is the TX valve on a 1998 Pajero?

It’s mounted on the evaporator block behind the glovebox, where the refrigerant lines pass through the firewall. Access typically involves removing the glovebox and trim, then disconnecting the lines after safe refrigerant recovery.

• Should the receiver–drier be replaced when changing the TX valve?

Yes, it’s strongly recommended. The drier captures moisture and debris, renewing it when the system is opened helps protect the fresh TXV and compressor and supports stable pressures and cooling performance.