Parts for your 2008 Honda Stream-Tx valve

2008 Honda Stream TX-valve: fitted, purpose, and care

Based on Honda’s technical literature for the RN6–RN9 Honda Stream (HVAC section of the 2007–2012 service manual) and the Honda Electronic Parts Catalogue, this model is fitted with a block‑type thermostatic expansion valve (TX-valve) at the evaporator, using R‑134a refrigerant. In other words, the TX-valve is relevant and used on the 2008 Honda Stream, not an orifice tube. General HVAC references from DENSO/Sanden training material support how the TX-valve controls refrigerant flow to the evaporator to stabilise outlet air temperature and system pressures.

The TX-valve’s job is to meter liquid refrigerant into the evaporator while responding to evaporator outlet temperature and pressure. By doing that, it keeps the evaporator just shy of freezing, giving consistently cold air without icing up. On the 2008 Honda Stream, the TX-valve is mounted at the evaporator case behind the dash, and it works in tandem with the compressor, condenser, receiver–dryer, and the blower system to deliver steady cabin comfort.

It isn’t a scheduled replacement item, it’s replaced when there are symptoms of sticking or restriction, or whenever the system has suffered contamination (for example after a compressor failure). Typical signs that point toward a TX-valve issue include:

• Air-con that’s cold on the open road but meh at idle
• Frosting at the evaporator or on the suction line, plus erratic vent temps
• Uneven high/low side pressures that don’t respond to normal servicing

When servicing a 2008 Honda Stream air-conditioning system, best practice from Honda’s service procedures and industry HVAC guidance is to:

• Recover refrigerant properly and leak-test with dry nitrogen and soapy solution (or an electronic detector) rather than “top up and hope”
• Replace the receiver–dryer whenever the system is opened, and always use new O‑rings lubricated with the correct PAG oil specified by Honda
• If replacing the TX-valve, keep the mating faces spotless, torque the fasteners to Honda spec, and cap lines to keep moisture out
• Evacuate for the recommended time, then recharge with the factory‑specified R‑134a mass shown on the under‑bonnet label, verify superheat/subcooling where applicable

Because the valve is buried at the evaporator, labour can be the main cost. Many owners opt to change the TX-valve when the evaporator case is already open for other work. For Australia and New Zealand, the job should be carried out by a licensed air-conditioning technician familiar with Honda systems and ARCtick requirements.

Popular questions

Does a 2008 Honda Stream use a TX-valve or an orifice tube?
Honda’s service manual and the Honda EPC list a block‑type expansion (TX) valve for the RN6–RN9 Stream. So this model uses a TX-valve, not an orifice tube.

What are common symptoms of a failing TX-valve on a 2008 Honda Stream?
Owners often report weak cooling at idle, intermittent blasts of very cold then tepid air, frosting on the evaporator/suction line, and compressor cycling that seems out of whack. Gauge readings may show low evaporator pressure or unstable differentials even after a correct recharge.

Can a TX-valve be cleaned, or should it be replaced?
If contamination is the cause, cleaning rarely restores proper metering for long. Standard practice is to replace the TX-valve and receiver–dryer, flush lines where approved, and ensure the correct PAG oil balance before recharging with the specified R‑134a amount.