Delica Canada | Mitsubishi Van Club

Hello guys!

I'm about to service my HVAC system and I'm wondering if anyone has done it before...?

I have L300 1993 dual AC system.
Shows R-134a post 91 but some still used R-12...?

If so... To whom do you know what type of refrigerant was inside (R-12, R-22, or R-134a)?
Also, to whom, did you have to add fittings so that a R134a Manifold gauge shreder valve could fit on?
And finally, did you have to replace the CCOT valve?

Thanks to anyone who can answers those!!!

I serviced mine: rebuilt the compressor, replaced all the O-rings, flushed the lines, and replaced the receiver-dryer, switched to R134a at the same time (Mine's a mid-'91, originally R12).

Mine had a service sticker under the engine cover saying "R12". The definitive way to check would be to look at the fill ports: I had to add R134a adaptor fittings. They just screwed right on.

Mine has expansion valves (TXV) rather than a CCOT, so no worries there. I don't see any mention of CCOT in the workshop manuals so I imagine yours has too.

I don't know how much oil or refrigerant was added- I left that (and the drain/flush/refill) to the AC shop. They also supplied the compressor rebuild kit and receiver-dryer.

Growlerbearnz wrote:..., switched to R134a at the same time (Mine's a mid-'91, originally R12).

So, am I to understand that you can just replace R12 with R134a? That it doesn't matter which refrigerant you use?

Correct, though you have to flush all the R12 out before putting R134a in, and you need to change the fill ports (R12-to-R134a adapters just screw right on). It's a good idea to flush out the old oil too- R12 oil is allegedly compatible with R134a oil, but your oil is 25 years old. It's a good time to replace it.

And how does one flush the lines?

I've always had the AC shop do it after they've removed and safely disposed of the R12 (we Kiwis are a little touchy about ozone depletion and the resulting skin cancers).

...though it looks like you can buy flush kits online. Not sure how they work, it looks like a cannister of solvent, perhaps propelled by compressed air. AC shops usually have a machine that does it.

Thanks for that info, Growlerbear