1G R12 to 134a refrigerant & oil

[AWD-Tony]

I’m converting from r12 to 134a. For r12, our cars take 33oz of r12 & 5oz of mineral oil. Now that I’ll be converting to 134a, what’s the correct capacity? I’ve read a few threads on this topic and I only found a single post saying you can’t use 33oz of 134a.

So...
How much 134a?
Is mineral oil compatible with 134a? If so, I guess that amount won’t change. If not compatible, what oil and how much?

Thanks
Tony

 

[Dericsh]

It’s been a while but I believe you want to put about 80-85% of the original capacity then top
it off if needed.

you want to look for POE oil, it’s compatible with both types.

 

[Jk's97DSM]

75-80% capacity but watching the low and high side gauges is key for AC stuff.

 

[AWD-Tony]

There was some oil in the evaporator. Can all the oil be removed when evacuating the system?

 

[1990TSIAWDTALON]

Oriellys sells a citrus type of cleaner that I used on my Chevy Caprice when I flushed it and put all new stuff on her for nice cold a/c.
@Jk's97DSM is correct in watch the low side and high side on the manifold (do you have a set of gauges Tony?).
Also, you can still find R12, and it is a colder refrigerant than R134 is. See here...............
https://www.ebay.com/itm/R12-R-12-r...=283617500746f6693c866ab643b3ab36c964ebeacdc0
I do my own a/c on all of our cars, so keep the low side pressure to 40 lbs or so and the high side no more than 350.
That is what I try to do and usually works out well.
Marty

 

[AWD-Tony]

Oriellys sells a citrus type of cleaner that I used on my Chevy Caprice when I flushed it and put all new stuff on her for nice cold a/c.
@Jk's97DSM is correct in watch the low side and high side on the manifold (do you have a set of gauges Tony?).
Also, you can still find R12, and it is a colder refrigerant than R134 is. See here...............
https://www.ebay.com/itm/R12-R-12-refrigerant-support-Artic-Air-Air-booster-6-cans-and-hose/283617500746?_trkparms=ispr=1&hash=item4208eb9e4a:g:~McAAOSwfaxdgUsV&enc=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&checksum=283617500746f6693c866ab643b3ab36c964ebeacdc0
I do my own a/c on all of our cars, so keep the low side pressure to 40 lbs or so and the high side no more than 350.
That is what I try to do and usually works out well.
Marty

Most likely not but I did see a set of gauges and vacuum pump locally for $100, so I might pick it up just to have it. This way I’ll know if there’s any leaks even if I don’t charge it myself.

Only oil was in the evaporator so I’ll pull that out AGAIN and flush it out. I know r12 is colder but seems to be harder to find. I read somewhere that you can’t buy it anymore unless you have a license and it’s not cheap so I’m just going with the retrofit

 

[1990TSIAWDTALON]

I use a guage set like this (yep its cheap but it works good) https://www.ebay.com/itm/3-Way-AC-D...=392927972829010b11f0d2874cecb28a936352fdf8f7
OR
https://www.amazon.com/JIFETOR-Mani...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

and a venture type vacuum pump that runs on my air compressor exactly like this.....https://www.ebay.com/itm/BRAND-NEW-...338922&hash=item23066d2b33:g:RTQAAOSwm8VUu0mX
OR
https://www.amazon.com/Goplus-Pneum...operated+ac+vacuum+pump&qid=1600964128&sr=8-7
I have lots of "friends" that want me to "tune up" their A/C, so this is what I use.
Just putting it out there.