My Compressor may be leaking anyway but we were trying to test the a/c and added r134. It chills great but the car originally had freon 12. Do I really need to replace everything? My mechanic swears he's done this before and no one has complained yet.

Thanks

Well, anything is possible.

Put it this way. If your comp was leaking anyhow, then you'd need to do a conversion to R134 sooner or later (or spend the cash on 12). That is, when you changed the compressor. Or compressor seal.

But then you should change the accumulator tank too, since it's been opened up to the air.

What I'm saying is, if you have another problem, here's what to do: Flush the system, change the accumulator and maybe the compressor, fix the leak, and go on your way with 134. The 91 system was designed for 134 to begin with, with the cooling fan and a different condenser.

/// I looked several places and the authority is SAE J1661, on the AC conversion. I won't have time to go look it up for several days/weeks.

What the manufacturer recommends is also the final word. There are seal materials effected by R134a and other seal materials are not. One of the recommeded oils used is chemically reactive with some seal materials and incompatible with mineral oil used with R12.

Find out what the manufacturer for your system says do and do that.

What is probably happening is that the kits used eliminate any possible problem regardless of your origional seal material.

I believe it is just a mater of time. The lubricants already in your system aren't surposed to be compatible with the R134. The pump will eventually die from being poorly lubricated I believe.

The system needs to have the oil flushed and replaced to use 134A, the expansion vale may also be replaced.

Use Freeze12 instead.

The mechanic only put a little in there... it was just to find the leak and see how long it lasted. It looks like there is some oil leaking from the compressor so I imagine the compressor will need to be replaced.

Try the Freeze12, alot of shops do not like it because they make more on the conversions. Also the 134a charge is critical and most can't get it right. Condenser is sized according to charge R12, and the correct charge using 134a is supposed to 80% of the original charge. And mixing oils is not a good idea it will probably cause compressor damage. The best way I've found to find freon leaks is with the GE detectors they have a built in pump to draw freon into the detector. I found a leak in my evaporator on my truck and started using the Freeze12 after I ran out of R12 works great.

You are asking for trouble unless your mechanic swapped out the mineral oil used for R12 for ester oil that the r134a needs. That is the absolute minimum for a refrigerant swap-- some argue you should also change the receiver/dryer and possible the orifice valve and o-rings.

Good luck!

>some argue you should also change the receiver/dryer and possible the orifice valve and o-rings.

receiver dryer - no the flush will take care of this

orifice valve - maybe

o-rings - not unless they are leaking

and I'll add, use Freeze12 and you won't have to change a thing. As I've said before I'm on my 3rd cooling system with freeze12 and it works well, oh, and I even have a trace of the old R12 in the system.

I have a 244 volvo 1991 and I just change my conditionner pump. Because of the highest price of the R12, my garagist change the fittings and simply use R134 with ester mineral oil. You will not have any problem unless your garagist have not used this ester oil. The mix of these 2 freese without this mineral oil will be like putting sugar into your gaz tank.

Just fittings have to be changed, unless your system is in bad condition.