A/C R12/R134 Conversion

[Malo83]

My A/C on my truck is still the R12 and it's been running great for the last 10 yrs but lately it's been slowly starting to loose efficiency, like when sitting at idle the air won't be as cold as when it's running at speed, which to me sounds like it's running low on R12, going to go looking around tomorrow for some R12 to charge up but everybody i've talked to says there is none available think i'll be good for the rest of the summer but thinking of switching over to 134 next year, my question is what is invoved in the conversion??? and done right???

[Pyrotechnic]

There is tons of misinformation out there with the whole R12/R134 deal.

R12 is still out there. You just can't buy it off the shelf, you must be a licensed A/C technician. It's still fully legal to use. The only problem is whats left is stockpiled and it's not being produced anymore. If you don't mind the high cost, you can still get it. If all you need is a top off, it may not be that costly.

There are lots of opinions on the conversion. Some conversion kits say you don't need new seal, o-rings, or even a flush for that matter, just fill the thing with R134 and the appropriate oil and it's all good. Supposedly, the remaining mineral oil won't mix in and just goes to a low spot in the system, and the mineral oil on the existing o-rings will protect them. They say even the existing dryer is ok.

Others say you need change everything, seals, o-rings, complete system flush, and a new dryer.

I have yet to do the conversion although I will very soon, this is just information that i've come across. I'll be starting from scratch with my A/C and I can't justify the costs of R12 when R134 is so cheap AND readily available to the public.

[Malo83]

Thanks Pyro, i'm gonna check around the various shops around town and see what I can come up with.

[Captkaos]

Ditto, on the above. I just did this to my '90 Suburban. You can find R12, but it is like $40 for a 14oz can, where 134a is $5.
Mine had everything hooked up, but wasn't working and there was no pressure in the system, so I decided to convert it. I had a friend that does this for a living and he said only replace the O-rings you have to, which is what I did. I ended up pulling the whole system apart though, so I replaced them all. (autozone has an o-ring kit) Then I used some flush for the AC and flushed the whole system. (I have front and rear air on the burb).
put it all together and pressure filled it with air to check for leaks, once everything looked fine I pulled a vacuum on it and put 2.5 cans in it.

If yours needs topping off, you may want to check the system for leaks, but I wouldn't convert it if it was functional. I know where 13 16oz cans are for about $45 per can, but.....

[Phuloi68]

r12 is all over ebay. Should be able to come up with a can(for resale).

[82c10]

get some freeze 12, i am pretty sure it is cheaper than regular r12,

[TexasJeff]

Hey Guys, my brother-in-law is a A/C tech and really knows his stuff. He says you can convert from R12 to 134 as long as you pull a vacumm on the system and not have to replace anything. He does recommend if there are no leaks in your system to pay the extra money for the R12 it just cools better than the 134. Normally it does not take much R12 to top off a system. I converted my system to 134 because I have a small leak under the dash and did not want to pull everything (aftermarket air) out of the interior to fix it until I am ready to replace the interior on it (which next on the list) So the last couple of years I have thrown a new can of 134 in the system and I am good to go the the summer.

[dswancutt]

I recently had my 92 Bonneville converted to R134. I had a the dealer do it and it cost me $120.00 and I don't know what they replaced. It does take a little longer to cool down, but once it get to temp, if has no problem keeping it cool.

[Malo83]

Well had the system checked out and no problems with the mechanicals both low and high press readings were good, seems I have a air duct door that is not fully closing letting warm air into the system which is not noticeable at speed but is at idle or stopped guess I know what will be on the agenda this weekend just relieved it was nothing more serious, trying to hang onto the R12 as long as possible, still colder than the 134 .
John

[Phuloi68]

That little plastic piece is almost always broke on these older trucks(on the flapper door). I would bet a chocolate donut that at least 7 out of ten of these older trucks has their's broke(unless it's been changed).
I change them by pulling the glove box off, then take the plastic piece directing air up to the defrosters off. It's right there on the door. I use a pair of pliers to force the little pin(looks like a nail) out, take the little screw out and slide off the rod. Just reverse the process putting it together.
You might want to look at the little plastic piece(for adjustment on top of the heater box also. It is cheap and is a good time to replace it also.

[Malo83]

Thanks for the heads up Phuloi

[Captkaos]

You might want to check for vacuum leaks also if the flap is ok.

[Phuloi68]

Originally Posted by Captkaos

You might want to check for vacuum leaks also if the flap is ok.

I forgot to mention that.... seems like the ones I dealt with, the hose right behind the carb comming off the tee (on top of intake) is almost always cracked or dry rotted. First time I replaced one, scared the hell out of me cause all kinds of things started working.
I am still willing to bet a choc donut that plastic ear is broke.

[boxrodz]

Here's some information on A/C; http://www.allpar.com/eek/ac.html.

As Phuloi mentioned, the bracket on the flapper door ends up breaking in time. I used part of the metal structure of an old PC to fab up a metal bracket. No plastic... no problem.

[Phuloi68]

I just went to chevy and ordered it. took a day to get it and just a couple of bucks. Actually, I bought 4 or 5 to put in various trucks.
I figure, if they held up for 5 or 10 years before they broke, that was good.

[sla90lx]

I second 82c10, I replaced the high side hose in my 90 mustang last year and recharged with freeze 12 and I can't leave that sucker on high for too long. The only drawback is you have to have a license to get it but parts stores carry it and it's about $9. bucks a can.

[Phuloi68]

You are supposed to have a license for R12 but I don't think you need one for Freeze 12.. You can get cans of r12 from ebay(if you want to pay the price). If you are the winning bidder, you send them a letter you are getting it for resale--------------

[AceX]

My truck is converted to R134.

The conversion requires all new seals and o-rings, a new dryer, a system flush. The new dryer will require a new sensor which will need to be spliced into the existing wiring harness for the old sensor.

You can contact Precision Auto Care in Woodland, CA for more information and perhaps they can get your their parts supplier's number as well. 1-530-661-0370

[Phuloi68]

Originally Posted by Phuloi68

That little plastic piece is almost always broke on these older trucks(on the flapper door). I would bet a chocolate donut that at least 7 out of ten of these older trucks has their's broke(unless it's been changed).
I change them by pulling the glove box off, then take the plastic piece directing air up to the defrosters off. It's right there on the door. I use a pair of pliers to force the little pin(looks like a nail) out, take the little screw out and slide off the rod. Just reverse the process putting it together.
You might want to look at the little plastic piece(for adjustment on top of the heater box also. It is cheap and is a good time to replace it also.

.

I see Ocbaud put a post on this forum "Help with heater controls". He put a picture in showing this plastic piece and where it breaks.
Check it out.