Air conditioning R12 to RS24

Page may contain affiliate links. Please see terms for details.

mercmush

Active Member
Joined
Apr 13, 2009
Messages
269
Location
London
Car
w222 S500e PHEV 2014
Hello all forum members, not sure if I've posted in the right place but I just wanted to share an excellent a/c engineer's services. My 1991 560SEL suffered the usual nonsense from the previous owner about the a/c just needing regassing to magically come to life again. Against my better judgement I still took a punt and bought the car anyway ( having suffered from an expensive weakness for w126s for about 25 year now...).

I know that R134a is now king but I thought I'd google for anyone who might be honest and competent enough to get the RS24 in and tell me if the whole process was worth doing beforehand rather than just regas, get paid and drive away as quickly as possible.

I had the great fortune to find a chap operating out of the Surrey area called Paul Clements on 0794 107 3136 ( Mobile car air conditioning service Surrey 0794 107 31 36 ) who checked my entire a/c system first for leaks, then if the compressor was a "gonna" or not and then in went the RS24. What a relief to feel the cold air coming out of the vents !

So if you have an old w124, 123, 126, 140, 201 etc etc you could do a lot worse.
 
What's the advantage of RS24 over R134a, is it just price or does it not need the conversion I gather R12 to R134a does?
 
I think the advantage is price as the a/c system in my car is still all the stuff that was there from its origin in 1991. So the RS24 went in without any conversion required at all, just working a compressor & condenser etc etc.
 
Sorry I meant to write a working compressor & condenser etc etc.
 
Thanks, I'll look into it as I have a 1992 Corvette which runs R12 but never worked in the 5 years I've owned it and I'm not keen on the idea of a £150+ conversion to even see if it might rise from the ashes. In the 1980's I used to repair and regas mobile plant air con but I'd not even heard of RS24 before.
 
Hello all members, although it is very embarrassing for me I need to "adjust" my recommendation in my first post above regarding old a/c systems.

The man didn't check my a/c system for leaks properly as a few weeks later the system went back to blowing hot air in my face. I thought I'd give the whole thing another punt and called subzero mobile automotive air-conditioning on 07843 936 155.

A fellow called Ian turned up and informed me that my condenser was leaking. He ordered a replacement, fitted it and then regassed with RS24 and now my a/c is working properly once again.

He's based in Folkestone, Kent but covers the M25 area ( I live in Morden SM4 ). Good luck for anyone who needs an old R12 system being brought back to life with nice cold air especially with the current weather.
 
Last edited:
Hmm.... Is it really that complicated & expensive to convert a R12 a/c system to run on R134a?

So far I've had a '91 Granada 24v 'converted' - a new drier, condenser (old was was leaking), pressure switch and new port adapters to get the system working again. I had it for 5 years and sold it to a friend. Must be 9 years now and apart from a regas, it still works.

My W126 was similarly done, again after the condenser failed back in 2000. Granted they both aren't daily drivers and don't do many miles annually, but the bottom line is it works fine. Probably not cool enough if you lived in the tropics or Texas, but in the current British summer heatwave, my W126 is as cool as my Honda.
 
Our old 1990 300E-24 was converted a few years back when it needed a new condenser. As far as I am aware no other parts were replaced and it worked fine for the next 20,000 miles before it was written off in Valencia.
 
I converted a 560SEL to run on modern refridgerant and I got a kit consisting of a couple of seals from my local MB dealer.....these were for the pipes unions where they join up with the condensor. Very easy and very quick to replace and had no problems from there on in.
 
On all of my cars, all I have done is used the conversion kit available widely and followed the instructions... I have never had an issue.
Just have to remember that you use 80% of the stated R134 quantity.
 
It looks like RS24 is basically R134a and butane mix that's supposed to help carry the mineral oil that was used in R12 systems. R134 molecules are smaller then R12 molecules and require barrier hoses. If not, you'll always have a slight leak through the hoses and seals.

Blends are not that great as different gasses leak at different rates so you're probably better off converting to R12, the difference is that you have to do is flush the system and use PAG or ester oil.

I'm not sure what the deal is in the UK, but R12 is still available in the US (old stock) and prices have come down significantly. So much so, that there is no sense in converting.
 
R12 is not legal to use in Europe....
 
Hello all members, although it is very embarrassing for me I need to "adjust" my recommendation in my first post above regarding old a/c systems.

The man didn't check my a/c system for leaks properly as a few weeks later the system went back to blowing hot air in my face. I thought I'd give the whole thing another punt and called subzero mobile automotive air-conditioning on 07843 936 155.

A fellow called Ian turned up and informed me that my condenser was leaking. He ordered a replacement, fitted it and then regassed with RS24 and now my a/c is working properly once again.

He's based in Folkestone, Kent but covers the M25 area ( I live in Morden SM4 ). Good luck for anyone who needs an old R12 system being brought back to life with nice cold air especially with the current weather.

Hello Sir,

I'd love to know whether your system is still working. Is it?

If so, I might contact your Folkestone chap when I visit my mum in Kent.

Thank you and all the best.

RayH
 
Hello RayH

Sorry for the late reply and yes my a/c system is still working. Good luck with yours.
 
Thanks for posting. I really wouldn't mind getting my 190's a/c running and the old man lives in Folkestone so very useful!

(It was converted to R134 by the previous owner but that was many moons ago!)
 
My w126 SEC 'needed a re - gas' when I bought it. I had a good experience with my other w126 (SE) with a mobile guy near me, really seemed to know his stuff and got it going nicely. Managed to stop a leak with sealant too on that one.

The SEC hadn't been converted but it held a good vacuum so he used rs24 and it came to life nicely. It cools the car well, lasts about a year and a half before it needed more gas. I thought that was ok considering it's an old system.

The only with the rs24 is it seems a bit expensive.
 

Users who are viewing this thread

Back
Top Bottom