m73m95

I have decided to address my A/C problems. Its already over 100F in Las Vegas, and my "windows down, sunroof up" thought isn't working as planned. I was quoted today for $250 for a shop to do the swap. Evac the old R-12, retro kit (??) and the new R-134 w/ PAG oil.

First off, I don't think this price is to bad, but I think I can do it myself cheaper....well, I KNOW I can do it cheaper. What do you guys think? I'm not worried about my ability. I was a mechanic in my youth (Just never worked on A/C). Also, I found another shop that will do it with R-12, and will only charge me a 1/2 hour of shop time and the price of the freon. Also, not to bad. But, I think in the long run, it would be better to make the switch to R-134

So my questions to you all:
1. Is switching to 134 going to work? Here in Las Vegas, it gets 120 petty often, and I do sit n traffic from time to time. Will it still be cold at an idle?
2. If I spend the money for the R-12, what are the chances it will last another 22 yrs? lol
3. I can do both myself (I'm sure I can find some freon) but is it worth my trouble for prob only saving 100 bucks? (After buying all the tools)

I know a ton of people on here have done both, and I have searched for a few hours now, but never really found a definitive answer.

Thank you

speedtek

In Hawaii it gets in the upper 90's and gets d*mn humid!

The first thing is to change the dryer. then find someone who can suck out the R-12 and at the same time you will get the system vacuumed out at the same time. then I go to Walmart and get (1) R-134A conversion can and one regular one and charge it up. So far I have not had any problems with any cars I did. (over 50 cars in 2 years). and they blow cold. Start at about 10% less capacity than stated. (look for the sticker or look up the specs for your car)

But if your system has no pressure you will need to figure out why it leaked. for this you can just start with the R-134a to figure out the leaks.

GloriaRedStang

I paid somebody more than $250 to do the R-134 conversion and it's money well spent. It blows colder than one would expect. I'm also in Hawaii and temps rise, although not as bad as the desert, and it continues to blow cold. Only when I've been parked out in the sun without my sunshade up, does it take a while to cool, but I have the same problem with my 2004 truck.

Whether you do it yourself or spend that $250, you will be happy you did.

marky522

If you have R12, and your system isnt leaking why would you change to 134A? R12 is so superior it isnt funny. I recently had a 928 in the shop that was a R12 car, when you start the car while standing still ie no air across the exaporator it was damn cold, no 134a system is that good.

If your going to do it yourself you will need to have the system sucked down, replace the drier as said above, then have the system evacuated again, then you could charge with your choice of freon, dont forget to add oil. Your system will never be the same if you convert to 134A.

Mark

m73m95

I had the pressure checked, and I have about a 1/2lb of r-12 in the system. I'm trying to decide if it leaked out, or its just a 23 year old system, and recharging would last a long time.

If it was leaking, I would think it would ALL be out, and not just leave the 1/2lb.

I honestly would like to keep it R-12, but if its going to leak....even very slowly, I don't wanna spend 100 bucks every summer to refill it. Where, 134 would be 20 every summer

dacula951

I think the answer on whether or not to convert depends on the present condition of the system and how it got there. Is everything functional and is it just a little low on freon due to an extended period of non-use, or has everything leaked out and leak repairs are needed? Do you know if there is still some refrigerant pressure in the system?

If only low and the system is sound I would suggest topping off with R12. While R134a will work OK with sufficient air flow to the condenser, a noticable loss in performance will likely be noticed when stuck in traffic.

On the other hand, if the system is now empty it may take some effort to identify leaks and you could possibly loose some expensive R12 even after you think you've repaired the leak(s). (This risk can be mitigated by pressure testing with dry nitrogen first).

Before doing any repairs yourself, I suggest doing a lot of research. You will at a bare minimum need a good low-micron vacuum pump (not one of the type that work off of compressed air) and a manifold gauge set. If converting you'll want to remove the compressor in order to drain as much of the mineral oil out as is pratical and refill with PAG.

dacula951

How was it determined that there's 1/2 pound in there by pressure checking? The pressure will be the same if there's 2 lbs. of liquid refrigerant in there or a fraction of an ounce. The pressure will only go down when enough has leaked out to the point where all the liquid is gone.

One of the best ways to reduce leakage is to use the air periodically. I try to turn mine on a little every time I drive it (weekend car).

944Sknight

If your A/C system still works well, use Freeze 12 which was designed to replace R-12. This is available
in automotive stores other than your regular auto stores. It works very well. Keep the $250. in your poc-
ket and buy me a 6 pack. lol.

m73m95

I know there are alot of substitutes for freon...and I would prefer not to use them. I'm sure they work fine for most people, but it seems a little to "J B Weldish" to me. Just a temp. fix for a problem.

The system is low enough for me to have to jump the terminals on the pressure switch to get the compressor to turn on, But when I had a mechanic put the gauges on it, he said there was still some freon in it.....maybe 1/2lb.

It may be wishfull thinking, but I think its just low from non-use.

I think I'm going to have it evacuated professionally, and vac leak tested. If that turns out ok, I'll refill with r-12. I can get certs online for 20 bucks, then buy it myself for alot less than a shop.

Dacula --- how do I dry nitrogen test? Is it something I can do myself?

marky522

I dont quite understand what you are saying here, but you can tell by the pressures what percentage of the charge is in the system by the pressures while operating.

marky522

The down side to using Freeze 12 is no one will touch your system after you have charged it with this, as it will contaminate there equipment.

Mark

austin944

My fully charged A/C lasted about 4 years before much of the R-12 leaked out, leaving just enough to see in the sight glass when I jumper the low pressure switch.

The tech who removed the rest of the R-12 from my system said it was a very small leak for the A/C to last 4 years, but I wasn't able to find it with a sniffer while it was leaking.

544DRS

I was just thinking about this today. My '83 944 is now on the road, and when I tested the AC today, it didn't blow that cold. Then again, it was only about 65F here, so I couldn't tell for sure. Still, I'm sure the AC needs some help, because the car sat for a couple of years before I bought it.

Should I presume my AC is R12? How would I know otherwise? And, if I've read this thread right, I'd be happier with R12's performance, or be happier with R134's price.

Thanks,

Nick

m73m95

Thats pretty much it. Save some cash, or skin on my *** from hot leather seats.

I've decided to go get it evacuated, and checked for leaks. If I'm comfortable its not leaking, I'll go with R-12. Its what our systems were designed for, and will work the best on hot days in the desert. My local shop wants to charge 90 bucks a pound for R-12. The system holds a little over 2 lbs, minus oil (and stop leak lol) so for 180 bucks, and a 1/2 hour shop time, I think its a good deal.

Then I can always add some later, on my next trip to Tijuana lol.

m73m95

PS.... I would still like to know more about the dry nitrogen test. If anyone knows about this


Also, if anyone would like to sell me some good used A/C equipment, I would be happy give them a good home!