xsboost90

didnt see anything about an EMPTY system- but i could have skipped it. If your system is empty, technically you should find your leak, replace the drier, and pull a vacuum on the system before charging. When changing from your stock R12 refrigerant to 134a refrigerant, you should empty the compressor of its oil and refill w/ appropriate amount of compatable oil like PAG.

or you could be lazy like me, drain the oil compressor oil, pull a vacuum and charge w/ 134a mixed w/ oil.

DarylJ

Definitely. And no, empty wasn't addressed. I felt that doing an already marginally working system recharge would be the best starter on this. When you get into empty systems, you get into a lot of other issues, as you know - how long has it been empty, why is it empty, what is dried out that needs to be replaced, plus the whole procedure for vacing the system.

On the other side of this, there's the "leaking system that needs to be recovered, repaired, and vaced", which is a whole other set of things to deal with.

Maybe if someone has a working late compressor they'll let go of for cheap I'll document the "resurrecting your A/C that's been disconnected for 3 years and didn't work for probably 5 years before that" procedure

DarylJ

OK, so I got email notification of GloriaRedStang posting this, but I never showed up in the thread:
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Thanks for the post. Very helpful. BUT: is the equipment you describe readily available to the general public and if so from where? Depending on cost of obtaining this highly specialized gear it may or may not be worth DIY-ing this.
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Good question. I missed that part.

Here's what I used:
- Manifold gauge set - used from Re-Tool $75.
- R134a hose adapters - new from Re-Tool $20
- R134a valve - new from Pep Boys $10
- 14 oz can of R134a and oil - Napa $18

You can skip the first 2 and get a perfectly serviceable R134a gauge set plus hoses that need no adapter brand new from Harbor Freight for $50. Mine are much nicer. They retail new for like $130. But its just not necessary for doing the occasional charge.

So, if you plan on doing this more than once in your lifetime, it's probably cheaper to buy the stuff and just do it.

In fact, you're better off, because you can check all of your vehicles in the spring time, top them off, and never get to the point where you're short cycling your compressor. Refrigerant leaks. Those hoses are called "barrier hoses" because they aren't considered fully refrigerant tight. Brand new cars leak refrigerant from the time they are charged. It only gets worse as you use the A/C (because of the pressure on the high side), so it likely you can use a small bump just about every season.

No, you need no certifications to get ANY of it. The only time you'll need a certification is for small (under 20 pounds, I think) quantities of R12.

FlatSix911

Daryl, well done!

What advice do you have for those of us who still use R12?

Pay the price for R12 or convert to R134? What is required for the conversion?

xsboost90

conversion to 134a is quite simple- contrary to popular belief there is no reason to swap all the seals in the system. You should swap the oil in the pump to a compatable oil like PAG or otherwise. Drier should also be replaced, the pull a vacuum and recharge. Your operating pressures will be different.

DarylJ

PAY THE PRICE. R134a is not nearly as efficient a refrigerant as R12. Both are green house gases, but R12 also likes to punch holes in the ozone layer. That's why it was phased out - not because R134a was better at cooling.

R12 is expensive because you can't manufacture it anymore. But you can recover and reclaim it. So cars with R12 in scrap yards are being drained as they come in and that is being sold off to reclaimers, because its liquid gold.

Get it while you can and stick with it. R134a in these cars works fine when you are moving. When you are sitting still - to quote Jeremy Clarkson - "its like an asthmatic sitting behind your dashboard breathing on you through a straw".

To fix that, you're need more surface area for the condenser and evaporator. I know I don't want to figure out how to make that happen.


Let's say your system is fine or just low.
- Evacuate the system of any existing R12. Requires an expensive machine. Like $1500 for a cheap used one. So you're paying someone to do this.
- get a fairly inexpensive kit, which includes service port adapters and a sticker that says it's been converted. Install those.
- remove the compressor and dump out the oil, and optimally run a flushing kit through the lines before replacing the compressor. (R134a does not mix with the same type of oil that R12 mixes with - the dumping and flushing is to get all of the incompatible stuff out)
- replace the receiver/dryer (that thing with the little window the high port is near)
- Evacuate the system with a vacuum pump
- Add POE or PAG oil (compatible with R134a)
- Charge as per the earlier posts

DarylJ

lol...tag team xsboost

V2Rocket

this is excellent thank you

im going to need to empty out all the R12 oil from my compressor and fill it with PAG before taking it to the shop to be charged but 2 questions:
1) is there anything i can use to flush out any remaining r12 oil or will the upsidedown draining trick by itself get enough R12 oilout that adding PAG wont cause any problems?
2) how much PAG to put in?

eniac

I've posted this many times here in the past years but here goes again:

about 6 years ago my R12 filled system stopped blowing cold. I bought a $35 R-134 conversion kit that was simply some adapters, a can of oil, and R134. I did nothing else but attach the adapters and fill with the oil then R134. It was nicely cold for 2 years before getting warm again. Every spring since I refill it with a small can of R134 and it lasts the summer.

Nothing blew up, nothing smoked, and I have cold air at an idle. Not as cold as R12 but certainly nice on a 90' day.

I do think I have a worse leak however this year, it's not as cold and only sucked up half a can...maybe the system just needs to be drained and re-filled but it's still cold enough for me. It's was 84' here today and I actually had to turn it off for a bit while driving because it was too cold inside my car.

vt951

My a/c was not working at all last year, and the system was evacuated and re-charged with r134a with oil (by xsboost actually) and I can tell you it really does work. It blows so cold it makes my teeth hurt.

I read a lot of horror stories on here about all the stuff that *should* be done to convert the system to 134, but I luckily took Dan's advice and just did the recharge.

DarylJ, this is THE BEST DIY I have ever seen. Nice job!

xsboost90

yeah I charged my car about two years ago-just to see if it worked before i did my bro-in law's car - and still has better a/c than my truck.

one good way to check for leaks- if your system is empty, charge it w/ a few lbs of nitrogen and use a leak detector to sniff for a leak- usually its at the compressor- or you can search around for a spot w/ oil seeping out somewhere. Mine have always had leaks at the compressor after engine swaps so i always buy those seals while doing the swap.

DarylJ

No doubt you can get away with that sometimes. I wouldn't be comfortable recommending it to anyone, but I'd likely do it myself if I were in a hurry. An old R12 system that's been steadily leaking just isn't going to have much of anything left in it. And if you kill the compressor from the oil mix, it's not the end of the world....it was probably on its way out anyway.

DarylJ

Just drain it. It doesn't have to be perfect. Hook it up the hoses loosely so that they can disconnect them to flush it. DON'T REPLACE THE RECEIVER DRYER. You do that AFTER you put the flush through it, so let them do that.

And you won't be putting the oil in. They will. Either with an in-line injector or with a refrigerant/oil mix.

V2Rocket

ok thank you very much

surfdog4

Can someone confirm that the location of the ports is different on '87 up? I read in the manual that the ports were changed, that the low side port is on the compressor, but the high side port is located where the previous low side port was (next to the shock tower on the driver's side)

I looked at mine after seeing this picture, and sure enough i have on port at the shock tower but nothing near the drier (have to get underneath to even see the compressor)

Thanks!