Parts for your 1987 Suzuki Jimny-Tx valve

1987 Suzuki Jimny TX Valve — what it does, when to replace it, and how to keep it happy

For the 1987 Suzuki Jimny (SJ410/SJ413, commonly known as Samurai in some markets), the air-con system uses a thermal expansion valve (TX valve/TXV). This isn’t guesswork: the Suzuki factory service manual air-conditioning section and period parts microfiche list an “Expansion Valve” at the evaporator inlet, and the dealer/factory kits of the time (Sanden/Denso-based R12 systems with a receiver–drier) were engineered around a TXV. So, yes — a TX valve is relevant and fitted on this model.

What does it do? The TX valve meters liquid refrigerant into the evaporator based on temperature sensed by a bulb on the outlet pipe. By maintaining correct superheat, it keeps the evaporator cold without flooding the compressor with liquid. That means better cabin chill, steadier low-side pressures, and reduced risk of slugging the compressor.

When these Jimnys are blowing warm at idle, icing the evaporator, or swinging wildly between too cold and not cold, a sticky or mis-sensing TXV is often on the shortlist. Abnormal pressure readings (starved low side with high high-side, or the reverse) can also point to a TXV restriction or overfeed.

Replacement isn’t an every-service item, but it’s smart to consider a new TX valve whenever the system is opened, especially after compressor failure, or when converting from R12 to R134a. Many owners have better results with an R134a-calibrated TXV rather than reusing an old R12 valve.

• Have an ARCtick-licensed technician (AU) or certified refrigeration tech (NZ) recover the gas and handle recharging — it’s the law.
• Replace the receiver–drier whenever the system is opened.
• Use new HNBR O-rings, lubricated with the correct oil (mineral for R12, PAG/POE for R134a as specified).
• Mount and insulate the sensing bulb firmly on the evaporator outlet at the clock position recommended by the service literature so it reads accurately.
• Evacuate thoroughly (30–45 minutes), charge by weight, then leak-test and verify superheat/vent temps.

A clean, correctly sized and installed TX valve helps these tough little trucks punch above their weight on hot Aussie and Kiwi summer days. Get the basics right and the Jimny’s air-con will feel far more modern than its age suggests.

FAQs

Does a 1987 Jimny actually have a TX valve?
Yes. The SJ410/SJ413 service documentation and period parts microfiche show a thermal expansion valve at the evaporator inlet. Factory and dealer A/C kits of the era were TXV-and-receiver–drier designs, not orifice-tube layouts.

What symptoms point to a failing TX valve on a Jimny?
Warm air at idle, icing on the evaporator, surging cabin temps, or pressure readings that suggest the evaporator is starved or flooded. After compressor failure, debris can lodge in the TXV and cause restrictions.

Should the TX valve be replaced during an R12 to R134a conversion?
It’s recommended. An R134a-calibrated TXV, fresh receiver–drier, correct oil, and meticulous evacuation/charge help restore proper performance and reliability.