Parts for your 2008 Honda Elysion-Tx valve

2008 Honda Elysion TX Valve (TXV): What It Does and How to Look After It

Based on Honda technical literature and parts catalogues for the Elysion (RR1–RR5, 2004–2009), the air-con system uses a block-style thermal expansion valve (TXV) at the front evaporator, not an orifice tube. Factory service manual procedures for the HVAC unit show the TXV sandwiched between the evaporator core pipes, and Honda’s electronic parts listings label it as the expansion valve. On models optioned with rear A/C, a second TXV is fitted at the rear evaporator as well. That means a 2008 Honda Elysion absolutely does run a TX valve.

The TXV’s job is to meter refrigerant into the evaporator so the core runs cold without icing up, keeping superheat in the sweet spot. In normal driving—idling in traffic or cruising on the motorway—the valve reacts to load and temperature changes so the cabin stays consistently cool and the compressor isn’t flooded with liquid. It’s a small, clever bit of kit that makes a big difference to comfort and compressor longevity.

As part of A/C servicing, the TXV isn’t a routine replacement item, but it’s worth a look if there are cooling complaints. Common clues of a dodgy valve include:

• Fluctuating vent temps, especially cycling from chilly to lukewarm
• Frosting on the suction line at the firewall or unusual hissing
• Manifold gauge readings showing very high or very low suction pressure that doesn’t match ambient

If the system’s been open to air, contaminated, or the compressor’s failed, the TXV can get restricted by debris or stick internally. In those cases, replacement is the smart play.

Replacement on the Elysion typically involves recovering the R134a, removing the glovebox and HVAC case access, unbolting the block-style TXV from the evaporator pipes, and renewing the O-rings. Best practice is to fit a new desiccant/drier (Elysion uses a condenser-integrated desiccant pack), add the correct PAG oil for any components changed, pull a deep vacuum, and regas to spec. For rear A/C models, budget extra time—the rear TXV sits at the rear evaporator assembly. Using quality OEM-equivalent parts (Honda/Denso) keeps the system quiet and reliable.

Expect around 1.5–3.0 hours for the front TXV depending on trim and whether the HVAC case needs to be split. In Australia and New Zealand, A/C work with refrigerant must be carried out by a licensed technician—so let a pro get it sorted and enjoy air that’s cool as on scorching summer days.

FAQs

Where is the TX valve on a 2008 Honda Elysion?
It’s a block-type valve bolted directly to the evaporator core connections inside the HVAC unit behind the dash, typically accessed via the glovebox area. On Elysions with rear A/C, there’s a second TXV at the rear evaporator in the rear quarter/boot trim area.

What are the signs of a failing TX valve versus low refrigerant?
A sticky or restricted TXV often causes vent temps to swing hot–cold, frosting on the low-side line, and odd gauge readings (very low or erratic suction). Low refrigerant more often gives consistently poor cooling, compressor cycling too frequently, and lots of bubbles in the sight area (if visible). Proper diagnosis with manifold gauges and temperature checks is the way to tell them apart.

Should the TX valve be replaced during a standard regas?
Not by default. It’s replaced when it’s faulty or if the system’s contaminated. Any time the system is opened, renew O-rings and the desiccant/drier, evacuate thoroughly, and regas to spec. In AU/NZ, a licensed A/C tech must perform refrigerant handling.