Hi Guys,


My 1990 XJS V12 still is running R12 and before I start calling mechanics, I was wondering what it may cost to convert to R134A. I know they replace a few gaskets, etc and also drain and refill with R134A. It needs to be done so I am getting prepared for the cost. LOL. Hopefully it is only a few hundred dollars.


My cars A/C still seems to work OK but not very cold as it used to be. Thanks for the help...

 

After a friend who works in the AC branch told me, you don't need to swap anything. Just make sure the compressor is R12/R134a compatible (the Harrison "blocks" should be, as mine in my 89 has R12/R134a on the sticker) and then have it refilled with the correct oil for R134a. That is important! The system also needs to be evacuated for a longer period.

My old Volvo 960 I had was fitted with a R12 system. No rubber gaskets or so were replaced. I simply had R134a filled into it and done. It worked for 2 years before I sold the car and probably still runs.

The only thing you may need, would be an adpater to fit the R134a hoses (filling hoses) to the R12 valves (like on the silencer of the compressor).

 

The only trouble I found with 134 port converters is the one on the muffler is dangerously close to the hood.
Complete conversion about £1000
http://www.ebay.co.uk/itm/Jaguar-V12...0AAOSwBLlVNSbN

 

That UK company may be frightening potential customers with that quote, which in my opinion is for replacement of many items that don't require routine replacement such as new compressor, condenser, all hoses and receiver/dryer and expansion valve.

Unless you want to completely refurbish whole system then just replace receiver/dryer for R134a compatible and appropriate filling port/ valves then air conditioning supplier will evacuate old system including oil and recharge (assuming no leaks).

 

I agree and did my own conversion or at least got all new parts from various suppliers
I only like to change things that could appear factory just to confuse show goers. My total was about £700 but didn't include condenser which is original. The compressor is from an xj40 that jdht were selling off, as you may be able to see in the picture rear top lug had to be removed from it to fit the 6lt HP side pipe . I think anyone who converts to 134 will be sadly disappointed with the performance of the original comp but that of course will depend on how good the cooling was in the first place.


1984 v12 HE

 

Was that your experience that cooling of R134a conversion was inadequate (assuming correct level of charge of refrigerant) ?

 

Def. In my own experience. Compared to R12. It now is about 3/4 (plus side) between R12 & 134 with original Harrison. Plus there's fuel economy gains I found on a run to Devon last weekend, I think Greg knows more about the advantages and is more eloquent than I. Lol

 

My 90 XJS(32K miles) is still all original, so I will see if any parts/components need to be replaced. I was told today around $300 which includes the kit for it to be converted to R134A. The mechanic also mentioned that R134A will not get as cool as R12. I am still deciding on where to take it so it may be a few weeks before I get it done. Its getting hot here in Wisconsin. LOL... Thanks guys!

 

My 89 runs R134 and is totally stock apart from 2 new hoses and seals as the old ones were leaking.

 

FYI:there are many resources for converting to R134a on the web. You must change the oil in the system to Ester style which is comparable with R12 and R134a. You also much change the connectors. As stated before you also must pull a vaccum before charging your system. Those are all the must haves. The optional things are changing to Green R134a Orings (very cheap) and new R134a grade hoses, and receiver drier. One thing to keep in mind is R134a molecules are smaller than R12 so using R12 o rings and hoses it will leak out eventually. Since all our cars our old it is cheap insurance to just go ahead and replace those components which are not very expensive. A kit of o rings is ~$10 and the hoses are ~$20-30 each. So it you keep the old hoses/rings you might have to top up in the spring each year. A/C is suppose to be a closed system that doesn't have leaks. The drier is recommended to be replaced whenever the system is opened up. It removes the moisture from the system which reduces the performance.

 

r134 performs pretty poorly in r12 designed systems. I did it a while back and I will switch to a replacement soon. Many are propane and butane mixes.

 

I switched my 86 coupe 8 years ago to r134 and its ICE COLD here in NE Florida. Works like a champ. ( seriously you have to run it in low AND its a black car) Propane and butane mixes under pressure under you dash in the interior compartment are not a good idea especially since it's converting from a liquid to a gas at the evap core. If yours isn't running cold enough something is not right. I also strongly suggest changing out to the expansion valve calibrated for r134 and not using the r12 original. http://www.aa1car.com/library/flamma...frigerants.htm
And yes, I'm a/c licensed, MVAC/HVAChttp://www.bernardembden.com/xjs/acup/index.htm

 

Mine doesn't, I still have the stock Harrison compressor, receiver dryer TX valve and condenser. Mine keeps the car cool in 40°C temps.

 

Hello everyone
good weather returning
I did charge the gaz
in my Jaguar XJ40
originally with the R12 gas now with gas R437A
no leakage and efficient cooling
here I am in compliance with the law
the operation cost about 160 euros

 

Check the height first.

The kit I put on my a6 dented the hood.

 

Had the conversion done and my AC is working great. Only had to have the conversion kit installed and then the ester oil and R134A. Total cost was around $140... It did take a couple of hours because of the long evac process and then slowly filling and testing the whole system for pressure and any leaks. So far, everything is working as it should and it gets very cold... Thanks for everyones help.

 

I think my 134 change out is fine with no issues . Your want to do o rings, oil in comp, and the filter that is rated for 134.I pulled a vacuum for ten hours just cause I could. There are no leaks and as reported above anything beyond mid settings and you will be frost bit in that car.

 

The r12 mineral oil that is in the system now wont mix with r134a.

You should try to get out all the old oil. The mineral oil tends to collect in the base of the condesor, evaporator, the lowest hoses and in the sump of the compressor.

The Harrison compressor is one of the few that has an oil sump and I've seen some with a drain plug. If it doesn't have a drain plug, you can remove the compressor and set it upside down and let the oil drain out the back, turn the compressor a few times to expedite the processes.

The lines, evaporator and condenser can be flushed with non CFC brake clean and compressed air. If you feel spendy get the the flush kit designed for the process.

When you are finished flushing you should reassemble with the green orings, (Harber fright has a kit), vac it down for an hour, recharge with PAG oil and r134.

It will work well but wont be like a modern car designed for 134a from the start. This is mostly because the TX or expansion valve will not be right for R134 and the condenser will be too small. This will mostly show up as low speed and idle warming of the vent temps.

You can mitigate the small condenser issue with an additional pusher fan installed on the condensers hottest spot. Just use your hand to feel for it and put the fan there.

There is some internet talk about a TX valve designed for R134a but I've never actually be able to get one.

 

All my original R12/oil was evacuated which seemed to take forever... I was at my friends shop for 3 hours and he was very meticulous on the procedure. Very experienced with Jags and pretty much anything else. The whole AC system is working very well and it is very cold... Maybe I was lucky because my car is in great running condition and very low miles and has always been maintained. He told me the system was still up to pressure before the change over and had zero leaks. So far so good... Knock on wood. LOL.

 

In my 94 XJ40 (with factory R134A) I had to replace the condenser and o-rings.

Hopefully the R12 systems use standard o-rings because none of the o-ring kits (eBay, Harbor Freight etc) included the correct size green o-rings, all rings in the kits were either the right diameter but too thin or the the right thickness and the wrong diameter. Napa couldn't supply the sizes either.

I finally had to bite the bullet and get them from the Jag dealer - who knew o-rings could be so expensive!!

Larry