A/C retrofit retrospective (1 Viewer)

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My ass-kicking days are over, and I thought I'd share my A/C experience with you guys as an FYI.

I had the AC fixed and going great, but went wheeling a little bit and it caused one of the hoses going into the firewall to loosen up. Lesson #1, use Loc-tite on all connections that could see movement.

Lesson #2 comes in the form of evacuation. Though you can buy the vac pump and manifold pretty cheaply, it's better to go to someone and have it done professionaly. With the leak, I refilled it once to make sure it wasn't a heat related pressure change, when it leaked again I added dye and more oil, then another can of freon/oil once I got the leak fixed. Now the system has too much oil in it and doesn't cool well at all. I tried evacuating it last night with my setup, but couldn't get all of the oil out. Replaced the freon and it cools even less...Good thing it'll be 100 degrees f. Thursday!

Anyway, if I were to do it all over again, I'd have someone diagnose system faults, fix it myself, use loc-tite on the threads for the hoses on the firewall (and maybe the dryer), have it professionaly evacuated, fill it with one of the retro kits that has the oil and freon mixed already (and I'd buy one of the $20 low-end pressure guages from O'Reilly) and fill it myself.

I've got a call into my guy up the street, and I'm going to see what it will cost to have the system re-evacuated and the crap recovered, then maybe refilled. I may refill it myself, but I dunno. If I have him do it, maybe he'll cut me some slack next month when I have to have my junk inspected :D .

So there it is, my A/C gift to the board, on the heals of all my idiot bragging. :doh:
 
I learned more talking to my guy up the street this afternoon; thought I'd share. This thread has been a huge hit, anyway.

With R134a, you don't have to have the system in a vac state to add the freon and oil. That's a plus. One reason to have it all professionally done is when they evacuate the system, it pulls out all moisture and any contaminates, which inhibit the cooling properties of the compressed freon. Wht my guy does after a flush is to send liquid nitrogen through the whole kit, which pulls any and all remaining moisture.

Second thing I learned is if you add to much oil, as I have, you have to pull the system apart and drain it - condensor, compressor, and put a new dryer in it, too. The reason the system won't cool when there is too much oil is because the oil and freon create a foam, basically, and that just don't work none...

Oh, most importantly, I learned that if you do convert to R134a from R12, you have to use 80% of what is called for in the system (for the 60 with single AC, you need between 650 - 750 grams of R12) - R134a expands differently than the R12, and creates more pressure. When you do fill 'er up with more R134a, your compressor will howl like crazy, and it will make the expansion valve sound like a trumpet and make weird breathing sounds. Ask me how I know.
 
Wow!
For a month or so you were like the god of FJ60 AC, & now you're confessing that you're a mere mortal?

Thanks for the PS. Saved me buying a bunch of tools I'd only get frustrated with.
 
Thanks for sharing!
I am in the midst of going through the same scenario you have been through.
I have done at least 15 retrofits and have never had a problem. This FJ60 is kicking my butt.
After three leaks and refilling my system three times, thought I had it licked.
New exp valve, new drier.
A/C worked fine for two weeks, driving down the road, A/C suddenly goes warm.
Take it home put my guages on. Pressures are perfect. 150 high side, 30 low.
Not even a hint of it getting cold.
Time for me to throw the towel in too and get someone else to look at it too i guess.
 
Correct, use less R134 than R12 when charging. Total of 8oz refined ester oil or poly-alpha for a system (each component ratains about 2-oz, so when replacing accumulator/drier, compressor, evaporator or condensor, add 2-oz). Always pull a complete vacuum - this is what makes AC work properly. Get all moisture out of the system...it eventually reacts/converts to an acid that eats your system. You should be getting vent temperatures in the low 40's to upper 30's dependent upon temperature and humidity. It is not possible to do proper service without vacuum pump and manifold gauge set.
 
I wouldn't convert to R-134a.
It does not cool as well as R-12. And with all the glass in a 60, this makes a big differece.
And the EPA is about to pull the same s*** with R-134a as they did with R-12. So no financial savings, and when the replacement is agreed upon, no one will manufacture R-134a anymore.
And then, in another 10 years, lather, rinse, repeat.
Last I heard, the front runner for a replacement is CO2. But now CA is calling this a greenhouse gas and pollutant, too.
Soon we'll all have to have catalytic converters in our lungs, too
 
I was just about to go through the same scenario Swank explained!
Thats some really valuable insight!!
I think I'll have the PRO diagnose, I'll R&R the bad stuff and fix the leaks (w/locktite) then I'll have the PRO evac and fill.
 
Here's another update and bit of advice from someone who jumps the gun and usually tries to fix what isn't broken in the first place.

Last night I put the guages on - I still need to do a 2000 RPM reading - but I went on a hunch that my diagnosis was totally wrong, bled off some of my R134a (had the pressure up above 35psi) brought it down to 20-23psi, and the system started cooling again. I used the manifold to bleed it off, and it took some of the oil with it, which needed to go anyway...

That said, I got it to cool again! I was really close to just pulling the system apart and starting all over again, but luckily I've learned my leason about diagnosing something myself without really knowing WTF I'm looking at, and took a step back. After draining the excess pressure, I bought one of those little dry AC thermometers and I'm getting a reading at the dash vent of about 43 degrees f. What I may do now is take it up to my guy and have him recover, flush and refill my system and add just a little bit of freon to get me up to about 25-28 psi on the low side - deferring to his judgement - that way I won't have to worry about O2, water vapor or anything else in the system. Should cost about $40.

FL Cruiser - Your pressure readings are a lot different than mine (at idle) When my low side was at 30psi, the high side was around 250psi. Now that it's down to 20-22psi, the high side reads close to 199-200psi (again, at idle) The FSM says, for R12, the high side should read from 200-220 psi at 2000 RPM, with the AC and fan set to the coldest setting. In the trouble shooting section it says that if it's cool for a while and seems fine, then it's warm (and I took it to mean over a period of weeks, not just driving down the road) it's a bum expansion valve. Do you have the FSM?
 
I don't have the FSM. Whenever my high side pressure got to 225 PSi, my high pressure line would get extremely hot and pressure releif valve would blow on the back of my compressor releasing refrigerant. Thought my guages were wrong or compressor bad.. Tried another set of guages, got same readings. tried another compressor, same thing happened, releif valve blew on it too..
I may have found the problem. The hose between my compressor and condensor felt a little spongy where it attaches to the condensor. I cut it open and found the inside of the hose had swelled almost shut. I could blow compressed air through it a few weeks ago when I checked the system, but now it's bad. Ill get a new hose and see what happens. If this doesn't fix it I'll go crazy :mad:
 

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