Parts for your 2001 Daihatsu Gran move-Tx valve

2001 Daihatsu Gran Move TX Valve: Purpose, Service Tips and Replacement Advice

Yes, the 2001 Daihatsu Gran Move uses a thermostatic expansion valve (TX valve/TXV) in its air-conditioning system. Technical references confirming fitment include the Daihatsu Gran Move/Pyzar M100/M110 factory service manual (A/C “Cooling Unit” section), which details a block-type TXV fixed to the evaporator, and the Daihatsu Electronic Parts Catalogue, which lists a “Valve, Cooler Expansion” for this model. Major aftermarket catalogues from well-known A/C suppliers also list an expansion valve for 1996–2002 Gran Move applications. The TXV is typically mounted at the evaporator on the cabin side of the firewall, secured with two bolts and sealed by O-rings where the refrigerant pipes enter the case.

The TX valve’s job is to meter the exact amount of R134a into the evaporator and keep the outlet superheat stable. That balance stops the core from icing up, prevents liquid slugging, and keeps cabin temps steady whether the car is crawling in traffic or cruising down the motorway. Compared with fixed-orifice systems, a TXV gives more consistent cooling and better efficiency across changing conditions.

While the valve itself isn’t a routine service item, it becomes a must-check component whenever the A/C system is opened, performance drops, or there’s contamination from a compressor failure. Common signs pointing to TXV trouble include:

• Poor or intermittent cooling, especially at idle
• Evaporator icing or noticeable temperature swings from the vents
• High/low gauge pressures that don’t match spec, or a loud, persistent hiss at the firewall

Replacement is straightforward for a trained technician. Refrigerant must be recovered by a licenced A/C professional (ARCtick rules apply in AU/NZ). Access is typically via the evaporator housing behind the glove box. Best practice is to fit new HNBR O-rings, lightly torque the TXV fasteners to avoid stripping the aluminium block, and replace the receiver–drier anytime the system is opened. If the system suffered a compressor failure, lines and condenser should be flushed and any filter screens checked for debris.

On reassembly, use the correct PAG oil (commonly PAG 46 for R134a in this model, verify on the under-bonnet label or service data) and evacuate the system under vacuum before recharging by weight to the factory specification. A dye-and-leak test plus a quick road test will confirm stable vent temps and proper cycling. Treated this way, the Gran Move’s TXV system remains reliably frosty through Aussie summers and Kiwi road trips alike.

Popular questions about the 2001 Daihatsu Gran Move TX valve

Where is the TX valve located on a 2001 Gran Move?
It’s a block-type valve mounted at the evaporator where the A/C pipes pass through the firewall into the cabin. Access is generally through the evaporator housing behind the glove box. Two bolts hold the valve to the evaporator fitting, sealed with O-rings on the inlet and outlet.

What are the signs the TX valve is failing?
Owners often notice weak cooling at idle, vent temperatures that swing hot–cold, or icing on the evaporator case. On gauges, expect abnormal high/low pressures that don’t track with ambient temperature. Contamination or a stuck needle inside the TXV can cause these symptoms.

Can a TX valve be cleaned, or should it be replaced?
If debris or black death from a compressor failure is present, replacement is the smart move. While minor contaminants might be flushed from lines, the TXV’s internal passages and diaphragm are delicate. Technicians usually replace the valve, renew O-rings and the receiver–drier, then evacuate and regas to spec.