R12 to R134A conversion

[northern-tech]

Im replacing a 1/2 HP hermetic compressor, on a small 2 door cooler. Original was R12. New compressor is R 134A.
Is changing the compressor enough, to satisfy the amount of mineral oil left in the system ?? :confused: I have read articles a few years ago, that recommened changing the oil several times, in order to get the residual mineral oil out. Is this somewhat true, or over - exaggerated ?? Thanks!

[Andy W]

I always blow out all of the pipework with OFN to remove any oil then use R49 as the refrigerant, even wholesalers will tell you it will be ok, people do not seem so worried about small amounts of oil mixing in smaller sysytems, now on a larger compressor I personally would change the oil.

[northern-tech]

OFN refers to.....? Also are you saying that R49 is the refrigerant to use for the system charge ??

[Andy W]

OFN is oxygen free nitrogen, R49 in the UK is a drop in replacement for R12 and will work with either mineral or synthetic oil unlike R134a which is designed for synthetic oil only, thats the way I would do it.

Oh by the way I have done literally hundreds the way I described, I did another condensing unit yesterday.

[afeef]

hi
flushing the system with a/c flushing fluid is better to remove all oil deposits ,,especially the burned oil that adhere on piping , this oil if it didnt be removed it will cause of blockage in capillary tubes.
changing the compressor is your chance to do flushing
regards
afeef

[Abe]

Afeef.

If you want to avoid having to worry about blowing out oil, replacinf with polyester oil, etc.

Then, as previous poster has pointed out, simply use a " drop in" refrigerant like R49

R134 is a problematic gas anyway, especially with copper spun driers, ( capillary tubes block up)

Ive used R49 for goodness how many years now with no probs

[g_norman]

i accidently used a r12 to a 134a unit, and it is almost a year and half now but the unit an upright freezer is still working until now. take note: until now it is charge with r12 and continue to its thing. im waiting for the the acid to work on the system but until now it si ok.

[g_norman]

Im changing my car ***** from R12 to R134a? what i need to change? do i have to change the expansion & compressors? my car a nissan vanette 95' model

[Andy W]

Im changing my car ***** from R12 to R134a? what i need to change? do i have to change the expansion & compressors? my car a nissan vanette 95' modelYou need a full retrofit, I bet it will cost more than your car is worth. A few years ago I remember Jaguar charging around £1600 for a R12 to R134a retrofit where as a recharge with R49 then was £50!:eek: