Air conditioning R134A swap

[sheppardpat47]

Hey guys, is this the kit for the JDM OEM A/C compressor ? I'm going to switch to R134A (the good way) but I don't know which kit to buy..

Context : I have a kouki 10/1985 Sprinter Trueno with all factory manual air conditioning system, it worked "okay" when I got the car from Japan but on very big heat waves it wasn't as cool as I hoped.

So I had the great idea to, well, swap from R12 to R134A without swapping anything. A guy hooked up a machine who tested the system, removed the old oil and freon, filled up with new oil and R134A and, it worked, REALLY, REAAALLY well. Like the coldest A/C I've ever felt in my life. Unfortunately, it only lasted from June 2025 to late October 2025, but it worked everyday with no problem.

A/C button is blinking, someone told me it was related to low pressure in the system, so, there's a leak (like who could have guessed lol) because R12 is thicker than R134A, so it won't leak through the rings but R134A does.

The results : I have now a complete stock R12 system, filled with R134A and R134A oil, but non working. Was working, compressor not seized.

I know I need to change the o-rings on the lines, and in the compressor
Not sure about the A/C expansion valve if I really need to change it or not? If I can keep myself from removing the entire dash it'll be nice

Someone in the MR2 AW11 Facebook group told me to use a RAV4 compressor instead, easier and OEM and bolts right in, but I'm not sure which one to use lol

If anyone have ideas...

[banpei]

I had mine converted by a professional aircon shop in 2024 and the aircon has been working without an issue since. They only changed the adapter to fill the system. He did tell me first pressurized the system and didn't find any leaks and he didn't replace any O rings. He told me he used a different oil than what you regularly use for R134a as the system is R12, but I have no idea which oil that is.
I can ask them what they used for it, but I'm not sure if they remember me 18 months later.

[sheppardpat47]

(01-22-2026 11:10 PM)banpei Wrote:  They only changed the adapter to fill the system. He did tell me first pressurized the system and didn't find any leaks and he didn't replace any O rings.

Well actually that's what they did on mine too, it worked beautifully for a while but now it doesn't work lmao I'm so sad tbh...
Perhaps I do have a leak? There was some green liquid near the condenser on the plastic when I got the car from Japan, who knows... Gotta call a A/C shop tomorrow!