Recharging airconditioning with gas
My car (Ge300- 463 SWB) is with factory fitted air con . Though the compressor engages and seems to be working, the cooling is not all that great, even when the control is set at Max. It Looks like the system needs some gas .. The trouble is that the compressor runs with R12 and I am told that this gas is now obsolete and no longer available. I am also told that it maybe possible to change to R134(?) gas and run with a new compatible oil. I am also told that this change is not really a good solution as the new gas does not cool enough ( something like 75% compared with R12) and that there have been incidents that thecompressor had been damaged as a result of this change.
Any ideas of what I can do apart from changing the compressor , drier,accumulator etc ???? Thanks
I had to buy a new receiver drier and charge up with the new type gas on my 463 when I changed the steering box. It wasn't quite as cold and it needed charging every couple of years, but otherwise worked fine. I suggest you go to an air con specialist rather than a Merc dealer, as there are alternatives to the Merc driers that aren't quite so expensive. I actually used a John Deere tractor dealership for my air con problem.
You can convert to the new gas but it is advisable to have the compressor and aircon. system seals changed to accommodate the new gas. As our chairman has mentioned, it would be better to renew the dyer.
I also agree that an agricultural workshop would be more competitive than a dealer or an independent specialist.
I'm just going through this on an old 70's car at the moment. Where are you located?
You will need someone with the equipment to check how much gas and oil to put in and will need a pressure test to see if you have any leaks anywhere before re-gassing. The receiver dryer is about £30-£40 and you could give someone your car details or measure the dimensions. R12 can be found and is the best option. R134 will leak out through your hoses. The change I think you need to change seals and hoses/adaptors. You will probably need a cheap adaptor for the tester to use his machine to service your system. There are alternative R12 gasses out there but i dont think they work so well...
You need to find an air conditioning specialist who has R12 and is willing to do you a recharge "off the books" as this is not so much obsolete as against EU regulations. However I am told that for various reasons Rolls Royce specialists are still using R12 . Some older Gs have York compressors and I have located a source for an adaptor plate that fits to the engine using the York mounting points but allows more modern 134 compressors to be attached. If anyone is interested I can probably find a picture to send.
Hi
How would it sit to just try swopping to the latter R134 with the minimum of recommended changes and see what happens?
I assume that your Aircon is not working now? If it works with R134 your sorted, if it screws a component up you were going to have to change it anyway to get it working? So you have not lost anything? My twisted Yorkshire logic...
This wiki page seems to be up to speed...
http://en.wikipedia.org/wiki/Dichlorodifluoromethane
I have seen plenty of MB product re gassed to R134 without any immediate issues, the Reciever/Dryer is probably due changing anyway due to its age as they rust out.
PS I can't believe that in the 12+ years since R12 has been out lawed that your G has not been regassed!!! How long have you had it? Have you no history or bills for previous work etc. It has served you well if the aircon has worked for 12+ years with no issues.
PPS Consur's option of an "underground" regas with R12 is more common than the powers that be would have you think, you will find someone in most cities if you ask the right people, think under the arches rather than under the silver star!
PPPS How did the Head Gasket job go? It must be sorted if you are looking at sorting bonus features like aircon?!?
Cheers
Gav
Hi Montreal
Thanks. The car is in Leatherhead, Surrey. Happy to travel to a R12 outlet.
I had a complete recharge at ATS - £44.95 (inc VAT), cheapest around and a quick and simple solution - though finding the second Gas nipple did take some time! Been using it and seems to chill the interior rather well (bearing in mind is already cool as its a V8! 
)
Spider1V
Hi Spider,
Are you sure that you have re gassed with R12 at ATS ???, So far I have not managed to find a workshop or home regassing service that can supply R12. They are all talking about conversion to R134a , which I don't want to do.
Leonidas,
I called and chatted with ATS and it was the R134a gas they used for my 463. What the technician did say was that the gas is the same its the oil that has changed, the R12 gas is now illegal, (and according to him - he knows that some people will fill R12 - if you have a crash, and the insurance companies check and if you have had it filled with R12 it is a case for non payout!) ......but all they do now is re charge with the Gas and put the correct oil in. What he did explain to me was there are two types of oil that are used today, one for Hybrid cars and one for Normal cars. I did explain to him that one of our members did have an issue's as when he had the 'new gas' (134a) it did not seem to be as efficient, it was then things got funny as his colleague said is that the 'Gent with the G Wagen?' and I confirmed, he then laughed and said 'it sounds as if your mate had the correct Gas, but they may have put the wrong oil in'' - could be an explanation?
Hope this helps
Spider1V
Thanks Spider. I think it sums it up nicely, as the compressor for R12 requires a special mineral oil. (0.2 ltrs) which is not compatible with the R134a . Therefore you must vacuum out all the system and recharge with R134a and compatible oil. It will take about 1kg of gas according to the manual. As far as I am aware It is not illegal to operate with R12 in the system if the car was designed for this. It is illegal to re charge with R12. Therefore the insurance angle is rather overated. Besides they will have to prove that the R12 was a contributing factor for the accident to happen. Having said this, I found in the ebay that it is possible to buy 4 x350grams cans of R12 either from USA or Hong Kong for about $11.50 +$10 shipping costs. . What is the catch? When ordering, you have to provide a what they call EPA (Environmental Protection Agency ???) certificate before they can ship the gas to you. In addition the shipment may take 4 to 6 weeks before you get it.
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Thanks for asking Gav.
Head job went very well indeed. I thoroughly recommend the poeple who did it. ( Blakesley Garage at Clakesley Northamptonshire)
Very thorough and very proffessional and very reasonable bill wise. They stuck to their quote even though they had clocked more hours than had allowed. Only additional job was to replace the water pump which found to be leaking- having been left dry for the best part of 3 weeks. Now the engine is totally "leak free".
On the subject of the aircon, yes I had it topped up about 4 years ago when the car was in Greece and R12 was indeed available through a reefer engineer who serviced boat fridges. I tend to run the aircon for about 10 minutes each week just to get gases/liquids in circulation. It seems to be cooling somewhat in a hot day, but nothing like my other car that nearly freezes you.