Aircon on a 1991 Eunos

Have many of you guys got the aircon running well on a mk1 1991?

My only reason for asking is mine is most definitely empty of gas and probably has been for years.

The car stood garaged for about 10 years as well.

Electrically it all seems ok, so probably just needs gas.

I’m currently doing a lot of fettling on our 1991 Eunos, and I’m now changing the cambelt, waterpump and belts etc.

Whilst doing this I’ll have the rad and fans out to clean and paint etc so its the ideal time to remove it all.

Do I spend the time on it, vac test, convert the valves, fill and test, bearing in mind the old gas isn’t available any more…

Or take the whole lot out and save a few kgs…

Opinions differ, but I think you nailed it yourself.

Replacement components are far away from their sell by date (bit like me really).

Removing the whole lot?

One less pulley and the weight saving was said, a while back, to be similar to a tank of fuel.

Lighter per volume that water but there we go.

A useful shedding of lard from a car painstakingly (per gram!) engineered for lightness as far as I’m concerned…as was done to my own Mk1.

Just more to go wrong again later on really…dodgy seals etc. 

Just my view mind.

To be honest I’d kind of come to the conclusion of getting rid.

As its sitting at the moment It’d be easy enough to remove, compared to getting it all back together, getting the valve converted just to find leaks everywhere!

I just thought I’d ask if anyone has had some success with it and what my chances would be… 


My S-Limited had it removed at some point; I replaced the fan-aircon combination switch for the correct non-aircon knob. You need to find a fairly large blanking plug for the bulkhead.

Having read previous threads I have the impression that many members aren’t too fussed about air con. Personally I feel extremely fortunate to have this system in my Mk 1 Eunos. It makes a huge difference when demisting the windscreen and it makes the cabin much more comfortable even when the outside temp isn’t particularly hot - a lot of heat is transmitted to the cabin from the engine and gearbox which is not well dissipated even with the roof down and even with the roof down you gain some benefit from the air con. I recently completed a 2,500 mile trip on the continent and could count the number of convertibles I saw over the whole trip on the fingers of 2 hands - I imagine it just gets too hot in a car without air con. On any long trip comfort is a very important consideration particularly when travelling with one’s spouse and it was a factor in maintaining marital harmony. I would happily invest a lot of my time and money maintaining the air con in my MX5. More resilient owners may take a very different view.




Mine is still on the car but one filling of gas only lasts one year as it is leaking from the compressor joints. I keep meaning to replace it but other home jobs keep cropping up to do that are more of a priority. I am going to try and sort the pump out over Autumn/ Winter time. I agree that it is well worth having it installed. I can’t imagine that the weight of it is that detrimental that it makes it worthwhile removing it all from the car. My philosophy is that if I can’t afford the petrol to run and drive the car the way I want to I would get rid of it.  


But your car uses R134, not R12. So you have more options. I’m expecting that systems in early cars are approaching the point of non-serviceability, due to lack of parts.

Fair point Saz and I did manage to get it re-gassed at MX5 restorer when the sills were done recently. I take it then that there are no aftermarket solutions for the early cars. One problem is that you cannot turn off the air-vents and even when the fan is turned off and set to demist a significant amount of air still comes through the vents and this seems to be warmer than ambient temp presumably because it picks up heat from the engine area particularly on a long run - so without air-con you just don’t seem to get much cooilng benefit from the vents.




There are aftermarket “solutions”, but you are also regassing/converting a system approaching 30 years old. I recall back in 1997, with a then 5 year old Eunos Roadster, that the aircon was pretty feeble compared to my US spec weedy  1992 Honda CRX HF, which could rapidly reduce the interior to a fridge like temperature, with outside temps of 40+.


Condition of the top boots and presence of the transmission tunnel insulation has a lot to go with ingress of engine heat.



Just a point to mention. When removing the compressor mounting bracket, which is quite substantial (heavy) one of the bolts is longer, there are four, it passes through the oil pump I believe? A lot of folk say to replace it in position. I never did on my supercharged mk1 and didn’t have an oil leak from there but worth searching and reading up about it if you’re removing the entire A/C equipment. Never an issue for me but   you never know.


It is getting very difficult to fend off the inevitable with both MK1/Eunos aircon systems.

Various age related problems with the early R12 system on the 1.6 mainly with the compressor pump where water ingress through the main seals causes bearing failure and seizing and the rubber flex section on the clutch plate getting to the end of its life and failing. No aftermarket replacement as far as I know and the dealer supplied pump was extraordinarily expensive when available(£600 from memory)

The R134a on the 1.8 is generally a slightly younger system. The compressor pump seems to have a better rubber on the clutch but can still seize up through water ingress. Worst part of this system is the condenser and the pipework attached to it on the top. It is almost impossible to remove these from a donor car without damage and no aftermarket replacement available as far as I know. If you have a 1.8 with aircon take particular care of pipe on top of the condenser, especially where the ‘P’ fixings hold it and the pipe union - I would plaster it in waxoyl regularly to stop corrosion. Not much that can be done to protect the condenser aside from the usual and recommended mesh grille to prevent stone damage.     

The aircon is certainly much less effective than in any other cars I have owned but it does just enough to make things acceptably comfortable. Looks like I will really have to look after what I have for as long as it works and thanks for the advice on this



Wow, thanks for all the replies, opinions and advise everyone.

Just on another note, I spoke to a wise man who installs and looks after all of our many aircon systems at work, and one thing he did say was if we’re considering filling the system with R134a, its imperative to make sure all of the oil from the old R12 is removed, if its not, when it mixes with the oil in the R134a, it will turn acidic and attack seals, bearings etc… just a note…

If the system is vac’d out properly you should be ok, but running on R134a  it may not be as efficient, given the age of it all too, could well be quite weak in operation.

I think mine will be coming out, and tidy up the engine bay a bit, the ac fan on the rad is quite rough looking too.

I’ll dig into the interesting point about the bolt and oil pump too, thanks…


If there’s any more views keep them coming…



My experience with domestic/industrial a/c engineers is that they nothing about the automotive a/c market.Filling a car with r132 is absolute rubbish. If the car was originally filled with r12 (in fact any car ),the retrofit gas is r134a. Even this gas is soon to be phased out ,so it will have to be the latest gas r1234yf (incredibly expensive) or there is a new blend ,nominated as r513a.

He didn’t say it can’t be done, just to make sure the old R12 and any oil is removed, and converted to 134a properly.

My mistake earlier, R134a is what I meant to say…

When I bought my 92 Eunos in June, the aircon seemed to be working well and was very cold. Recently, though, it’s started blowing white vapour into the car through the eyeball vents.

I was thinking that wasn’t an urgent problem, with winter coming and the aircon switched off.

I would imagine the vapour is just condensation and not a problem.  Back when my aircon worked I mostly used it in the winter anyway.  It’s a boon for instantly demisting the windscreen on a wet day.  If you get in the car with a wet coat on, the cabin is so small that it fogs up pretty much straight away but aircon is just the job for drying everything out.

Hmm, there should be drainage for the condensation that happens on the cooling element (evaporator). 

If the drain is blocked (leaf etc?) then you might be getting that condensation coming into the cabin as a mist. 

And no, I don’t know how to check it quickly, and the Mellens manuals look to be a nightmare for investigating the cabin air system.

That’s a good point.  Assuming the R12 system isn’t substantially different to the R134a version, the evaporator is in a plastic enclosure behind the glove box with a short rubber drain tube leading down from its right end to a drain hole on the transmission tunnel.  Easy to pop it off and see that it’s not blocked up.