R12 to R134a conversion....

[evol90accord]

Thats all B.S. You don't have to replace anything (unless you have a failed component or leak). All you do is evac the R12 including all the oil out of the system, install the R134a retrofit fittings onto the old R12 fittings, pull vacuum on the system for about 15 minutes or so, add the necessary amount of R134a PAG oil, and then charge the system with R134a.....done.

Like you said, thats if everything is working perfect and you have no leaks. If that were the case then why switch at all? R12 does cool better. If it doesn't leak your not going to care how much it costs to get the system charged, your not going to have to do it. However, components go bad and its a good idea to replace those three components if just one goes out (usually its the compressor). The compressor and drier are ALWAYS replaced together, so why not the expansion valve as well? Might as well, it goes bad too and you can't easily test it. Why evac the system and recharge when you can just do it all at once for a little more money and not worry about it for several years? Also, kind of like switching from standard oil to synthetic, the orings do have to be replaced or they will leak eventually.

Are you a certified a/c tech mrhonda? I know you know your shit, I'm just asking.

[evol90accord]

Minimum requirements for converting a system to R134a.

If system has any refrigerant R12 left in the system it must be reclaimed by an approved recovery machine.

Accumulator/drier must be replaced with an R134a compatible replacement. Conversion fittings and label must be added to the system. Label should have the amount of R134a used and quantity and oil type listed. If vehicle is not equipped with a high pressure cut off switch it must be added.

That is the required minimum! Flushing the system to remove the mineral oil and debris should also be done. R134a and mineral oil do not work well together so leaving it in the system with R134a is not recommended! O-rings should be replaced with either NBR or HNBR replacements. Adjustment of the pressure cycling switch may also be needed to achieve the best performance. In some cases an upgrade of the condenser may be required to achieve the original performance.

There are many different suggestions when charging a R12 system with R134a. System must be evacuated before starting the charging procedure. I suggest you start with about 70 percent of the original R12 charge and add an ounce at a time until vent and pressure readings reach the best available results. Remember it is easy to over charge a system with R134a so patience is important.


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Tim R. Bohringer
ACKits.com

BTW mrhonda, I'd like an apology. Not ALL of my post was BS. I do know what I'm talking about on some things

[mrhonda]

No, my point was just that you don't have to replace anything just for the sole purpose of switching refrigerants. The only time I would recomend switching is if there is a problem or a leak somewhere....if not, hang onto that R12 as long as you can. As far as the o-rings, I've never replaced a single one (unless it was already leaking) when switching a system to 134a and none of them have ever had a problem with leaking. Oh, and yes I am a certified A/C tech....and I have a license to buy R12 too.

[evol90accord]

Oh, and yes I am a certified A/C tech....and I have a license to buy R12 too.

Bastard. I'd still be using R12 if it wasn't worth its weight in gold and I could buy it myself

The only reason I went through all the shit I did when I did it was because my compressor kicked the bucket, and I have been fixing my A/C every year for the past 3 years. Driving with a hair dryer in your face (which is what its like in AZ) SUCKS so I decided I'd rather do it ALL at one time and do it right rather than just waiting for the next component to fail. Your right its not all necessary, but every a/c tech I talked to recommended I do all the shit I just listed. Its a worry free solution if you have the money, and the compressor really is the most expensive part. Like I said, if your replacing the compressor, now is a great time to do all that stuff and not worry about it anymore.

Edit: and BTW, there is no way to completely vacuum out old oil from your compressor. See this post here . Hence the reason you have to flush anyway if you are going to be retrofitting to r134a, because r12 mineral oil does not play well with other refrigerant gasses.

[xtremeskier97]

Wow....this thread is going places I didnt think it would go! LoL

Oh well. When I was replacing my radiator support, I had to disconnect a/c lines, so I had a friend come out and retrieve what was left of the R12 (only about 3 oz.) He then did a leak test to make sure everything was good. He found a leak in the shaft of the compressor. So, I replaced the compressor, drier, expansion valve (because r134a is higher pressure and may make the old one crap out soon), and all the o-rings (just because of all the stories Ive seen/read about the oils not mixing well, plus the fact that o-rings are cheap!) My new compressor came pre-charged with that P-oil, whatever it's called, and will be getting charged tomorrow by the same guy.

This Louisiana heat AND HUMIDITY is killing me, the wife, and our 2 poor kids stuck in the back of the coupe with just the vent windows!!

[evol90accord]

Man that sucks. I drove through a part of louisana last summer when I was helping my dad move to FL. I had no a/c and i could only roll down 1 window in a geo tracker, it fucking sucked. I couldn't get through that state fast enough. The a/c actually kind of worked, I think it was just low on refrigerant. You had to go 70 to feel any kind of mildly cool breeze...

Hope it all works out for you. Good luck if you didn't flush the evaporator or condensor, I remember all the orange shit that came out of mine when I did it (I think it was dye in the old oil). I didn't have compressed air and had to blow through all the stuff, boy does that shit taste bad!

[xtremeskier97]

Hmm...the guy doing my a/c charging did mention anything about flushing. Ill ask him today when I go out to meet him.

And yeah...it does suck with this heat.

What sucks more though is, is when my wife and I just moved here, we only had our RX-7. It wasnt running, so we walked everywhere. Once we put a rebuilt engine in it (and yes, I mean WE put the engine in it) there was NO a/c and our windows DID NOT work! The ONLY thing we had was the sunroof. So we would constantly have our hands sticking out of the sunroof while we were driving to direct some air into the car, and sometimes even opened the doors while sitting at lights! It sucked BAWLZ!!

[evol90accord]

oh man I'm sorry thats funny but unfortunate. I could just imagine driving behind you "Hey are they waving at us? Maybe they want us to pass..."

As far as flushing, the evaporator holds most of the residual crap, and don't let him tell you that evacuating the system with the vacuum will pull it out. I've seen pictures and video of oil in a vacuum, this shit doesn't move and it doesn't "boil" out. I thought it would too, but thats why they tell you to flush. Seriously read up some on ackits.com forums they have faqs and how-to's just like this forum does and its very informative. And much like us they aren't making any money off of it they're just giving away good info

Oh, and just because someone is a/c certified doesn't make them a know-all about air conditioning (I'm not doggin anyone). You can pass the test in about an hour on the internet and its rediculously easy. Hell if my pops can do it, anyone can!

[xtremeskier97]

hmm....Ill look into that. Better start reading now....supposed to go get it charged this evening.

How much does a flush usually cost?

[evol90accord]

hmm....Ill look into that. Better start reading now....supposed to go get it charged this evening.

How much does a flush usually cost?

I don't have a clue, I did all the work myself. Its fairly easy to pull the evaporator box out to flush it. Come to think of it, you might be able to just disconnect the two lines at the firewall and blow compressed air through one of the lines. It's been a year, forgive me. I took mine out completely to do it because I had to clean the blower motor of all the leaves, straw wrappers, and cigerrette platic wrap... I don't even know how that stuff gets in there.

Some people get away with not doing it, and since you changed your compressor completely you might not need to worry about it. I'm just like to be thorough. Have fun and hope you have a good a/c system you won't have to worry about for years.

[xtremeskier97]

Yeah...I had a bunch of leaves and crap in there too. Cleaned it all out. I am going to pull my blower too though. I get a wierd sound coming from it when the fan is on. I didnt put my glove box back on yet, just in case I need to get back to the evaporator for a leak or something while vacuuming/charging. I did stick my head in there and had a look while the evaporator was out changing the expansion valve. Blower area looked pretty clear.

On a side note, is there any way to get more airflow from the blower? It just doesnt seem to blow that hard. Maybe its just because it was low on refrigerant and it didnt seem like it was blowing hard, because the air wasnt as cold as it should be? You cant take the blower out without taking the evaporator out, can you? I think the evaporator box is in the way.

[evol90accord]

The blower should put out the same volume of air if its on heat or cool, so low refrigerant won't make a difference on that. If the blower motor seems weak and is making noise (assuming its not something stuck in the housing) consider replacing it, it could be going bad. I don't know of any way to "beef up" a fan though if thats not it.

I've been told (and its my personal belief) that our cars seem to have weak air flow at the vents compared to other vehicles. I know my buddy's Ranger blew a lot harder at the vents on max than mine did, but only when he was moving or revved the engine. Sit in another accord and see if it feels any better. Also make sure you have the right buttons pressed on the a/c control panel and that its not blowing at your feet

[mrhonda]

oooohhhh.....you live in AZ....yeah, no A/C does suck....I know, I grew up in Phoenix. BTW, it is possible to evac all the old oil in the system, but you need a recovery machine to do it.

[evol90accord]

BTW, it is possible to evac all the old oil in the system, but you need a recovery machine to do it.

Really?? I've only read and heard the opposite. How exactly is the recovery machine different from a standard vacuum pump other than it obviously holds the old refrigerant and oil? I watched the guys at Sun Devil Auto when they serviced my A/C, and the tech said that a little oil comes out with the refrigerant, but most of it stays in the compressor and evaporator (which is exactly what I've read).

I'm just trying to get my stories straight. He said specifically that you don't need to add more oil to the system with a recharge, its still in the system.

And is that part of the reason you can never pull a perfect vacuum, or is that just physics and atmospheric pressure being wierd?

[cb9tunerguy]

napa sells them