1991 AC refill - which type

[Mcgyver]

Hi all,

my 1991 which I purchased beginning of this year needs an AC refill as it's completely empty.

Now the manual is not mentioning which type to be used and also previous owner has no idea.

I read somewhere that by looking at the filling points it can determined which type, old R12 or newer types.

Any idea's ?

Manu

[Fredjohn]

If you check HERE in wikiLEC, it says R12 was standard.

Suggest you take it for a refill and see what the garage says.

[MPx]

I think its irrelevant what it was originally. You wont get R12 now. Indeed I don't think you can even get R134 that replaced R12. Every new iteration of the allowed gas adds more issues for the old systems to cope with (increased porosity etc) so it may require more than just a regas even if all of the components would otherwise function as originally intended. So yes, take it to an aircon specialist and see what's poss.

[Mcgyver]

Correct, but I wanted to check if anyone could identify by looking at the filling points if these are original or updated ones.

Also because I could take the car to a garage and they could just tell me to upgrade the whole system which maybe is not needed at all.

See this post : viewtopic.php?f=134&t=22554#p285508

So looking at the pictures are these the converted ones ?

Manu

[Simon_P]

Hi Mogyver,
The 1991 system was R12. Those look like R12 connectors and I don't think lotus changed them even for the R134a system, anyway it doesn't matter as you can buy the converter which screws on.

There are a few technical differences between the systems. Seals, Oil and operating pressure are the ones to keep in mind.
R12 has a slightly lower pressure meaning that conversion to R134a will be less efficient (you won't notice).
A lot is written about molecule size and leakage - in practice this means that you have to change the seals that you can get to and run the system regularly.
Oil - R12 uses mineral oil and 134a uses PAG the two are not compatible, but that isn't a problem. In practice you need to remove as much oil as possible, there is a drain in the compressor, you can remove the condenser and you will need to change the receiver drier - the black cylinder as you need a new one anyway. Some people say you need to flush the system, but as the small amount of mineral oil doesn't mix it will eventually migrate to the receiver drier.

Your first stop should be with an A/C specialist at least to identify if it is leaking and if you are doing any work yourself to make sure it is safely depressurised.

Get a quote for doing the job - you won't need more than a few o rings, adapters, a receiver drier, oil and gas - that's about £100. Anything that is broken and labour are where the cost comes in.

[Simon_P]

Gas - will be whatever the latest replacement is.

If it has already been converted there should be a sticker on the wing by the charging port.

[Mcgyver]

Thanks a lot for this info. I will get a specialist look at the current system.

[steve411]

Hi my name is Stavros from Athens and i am an s2 owner. Is it possible to have R134 SYSTEM with R12 connectors as Simons says (if i understood well).?? I was told that my connectors are R12, but i think i might have R134 A compressor and system (1995 s2 car). I was trying to see the compressor above the engine and i was struggling (i have the pictures of the two compressors and the differences). Is another obvious difference? In that case i refill with R134A using R134A adapters? Thank you